Building America Best Practices Series: Volume 1

Builders and Buyers Handbook for Improving New Home Efficiency, 

Comfort, and Durability in the Hot and Humid Climate

Michael C. Baechler

Pacific Northwest National Laboratory 

Pat M. Love

Oak Ridge National Laboratory

By

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

November 2004 • NREL/TP-550-36960
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agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect 

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Contents

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TOC-1

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

MANAGERS

Putting building science to 

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS 

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast 

and easy installation

MARKETERS

Energy efficiency delivers the 

value that customers demand

HOMEOWNERS

Shopping for value, 

comfort, and quality

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INT-1

Homeowners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-1

Quick Tips: Homeowners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-1

You’re in Good Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-1

How Quality Houses Perform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-2

An Energy-Efficient Home Will Cost You Less . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-3

Energy-Efficient Mortgages Can Help You Get More for Your Money . . . . . . . . . HOM-3

What’s the Score? (HERS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-4

Guaranteed Energy Costs and Comfort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-5

And There’s More - More Green for You and More Green for the Planet . . . . . . . HOM-5

What to Look For . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-6

Sources and Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-6

Homebuyer’s Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HOM-7

Managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-1

An Invitation to Building Company Managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-1

Building America . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-1

Quick Tips: Managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-1

The Business Case for Building Science and Energy Efficiency . . . . . . . . . . . . . . . . MNG-2

Properly Choosing Materials and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-2

Reduced Risks, Increased Productivity, and Fewer Callbacks . . . . . . . . . . . . . . . . . . MNG-3

From an Economic Standpoint, Everyone Wins . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-3

Customer Satisfaction and Referrals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-3

Consumers Expect More . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-4

Competitive Advantage in the Marketplace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-4

Take the Next Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-5

Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-5

Sources and Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MNG-5

Marketers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MKT-1

ENERGY STAR Qualified Homes: Telling Your Story . . . . . . . . . . . . . . . . . . . . . . . MKT-1

Quick Tips: Marketers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MKT-1

Increase Customer Satisfaction and Let Your Customers Sell Your Product . . . . . . . MKT-2

Sell the Value that Home Buyers Expect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MKT-2

How Industry Leaders Sell Energy-Efficient Homes . . . . . . . . . . . . . . . . . . . . . . . . . . MKT-2

Sources and Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MKT-4
Contents

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TOC-2

Site Planners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLN-1

Lot Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLN-1

Quick Tips: Site Planners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLN-1

Shade Trees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLN-3

Other Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLN-4

Sources and Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLN-6

Designers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-1

Quick Tips: Designers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-1

Building Science and the Systems Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-1

The Cost of Doing Business . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-3

Heat and Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-5

Hot and Humid Climate Design Best Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-5

Site - Drainage, Pest Control, and Landscaping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-5

Foundation Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-6

Structural Moisture Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-8

Structural Air Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-12

Structural Thermal Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-13

Heating, Ventilating, and Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-19

Mechanicals Management and Appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-28

Sources and Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DES-30

Site Supervisors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-1

Managing Expectations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-2

Develop a Work Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-2

Plans - Get Them Right . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-2

Plans - Keep Them Right . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-2

Contracts - Write Them Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-3

Pre-Construction Meeting - Have One . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-3

Permits - Grease the Skids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-4

Managing Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-4

Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-4

Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-5

Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-6

Spot-Check Inspection Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-7

Pre-Drywall Inspection Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-8

Pre-Occupancy Inspection Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SUP-9
Contents

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TOC-3

Trades & Crafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-1

Slabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-2

Housewrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-3

Window Flashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-4

Air Sealing - Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-6

Electrical Air Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-7

Air Sealing Drywall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-8

Air Sealing Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-9

Fiberglass Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-10

Masonry Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-11

Radiant Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-12

Duct Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TRD-13

Case Study: Habitat for Humanity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CASE A-1

Case Study: Atlantic Design & Construction . . . . . . . . . . . . . . . . . . . . . . . CASE B-1

Case Study: GW Robinson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CASE C-1

Case Study: Medallion Homes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CASE D-1

Appendix I: Homebuyer’s Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX I-1

Appendix II: Energy & Housing Glossary . . . . . . . . . . . . . . . . . . . . . . APPENDIX II-1

Appendix III: Code Official Tear-Outs . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX III-1
Welcome

Taking action in your community

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • INT-1

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

This best practices guide is the first of a series produced by Building America. The 

guide book is a resource to help builders large and small build high-quality, energyefficient homes that achieve 30% energy savings in space conditioning and water 

heating in the hot and humid climate. The savings are in comparison with the 1993 

Model Energy Code. The guide contains chapters for every member of the builder’s 

team—from the manager to the site planner to the designers, site supervisors, the 

trades, and marketers. There is also a chapter for homeowners on how to use the 

book to provide help in selecting a new home or builder.

• Homeowners will find how energy-efficient homes package value, comfort, economy, 

durability, and performance. This chapter is a great introduction to energy-efficient 

home technologies and provides helpful checklists of what to look for when 

home shopping.

• Managers will learn why building energy-efficient homes makes business sense. They will 

find out how much consumers value energy efficiency and the quality that comes with it, 

and how their company can gain market advantage by building energy-efficient homes.

• Marketers will learn about great resources for selling energy-efficient homes, including 

getting plugged into the ENERGY STAR nationally recognized branding program.

• Site Planners will discover the huge impact building orientation, landscaping, and shading 

can have on energy costs, plus learn tips on moisture management and pest control.

• Designers will learn about the systems approach to home design backed up by 

building science. They will get guidance on key building components for designing 

energy-efficient homes.

• Site Supervisors will get guidance on contract specifications, tips on scheduling and 

training, and handy checklists for quality assurance and commissioning inspections.

• Trades will find step-by-step, easy-to-follow illustrated instructions for adding key 

energy efficiency technologies.

The last chapter has case studies showing real-life examples of builders who are 

designing and constructing energy-efficient houses in the hot and humid climate zone.

We designed this guidebook to be taken apart, passed around, and updated. Give 

the sections of the book to the right people in your organization. Pass on pieces to 

subcontractors to help them understand your objectives. Copy it as needed.

This first series of guides helps builders understand and implement the Building 

America process to reach 30% energy savings in space heating and cooling and water 

heating. Future guides will aim at even higher levels of efficiency based on the latest 

Building America research, giving builders the knowledge they need to build even 

more efficient and durable houses.

The practices in this book are intended for the hot and humid climate zone. 

Handbooks covering other climate regions will soon be available.
Introduction

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • INT-2

Many builders choose to try out Building America ideas in a prototype house. After building one or a few 

prototypes they decide what features they will carry forward into their regular construction. This chart shows a 

process for working with a HERS rating professional, an engineer, or an architect to build this first house and on 

an ongoing basis. The person offering guidance could also be an internal designer who has become familiar with 

this document or has taken other Building America training. An educated staff will be the best means of selecting 

building science support.

Building America welcomes reader feedback on this first volume of the Best Practices Series. Please submit your 

comments via e-mail to: Michael Baechler (michael.baechler@pnl.gov) or Pat Love (lovepm@ornl.gov).

BUILDER

PHASE #1

Decision

BUILDING SCIENTIST

ENGINEER / ARCHITECT / HERS RATER

PHASE #2

Pre-Construction

Analysis

PHASE #3

Construction

PHASE #4

Post-Construction

Evaluation

PHASE #5

Marketing

PHASE #6

Lessons Learned

Management decides to go 

forward with best practices 

and company submits plan 

to building scientist

Company evaluates success 

and decides on next steps

Company creates marketing 

program to emphasize 

improvements

Site Planners integrate lessons 

learned in selection and siting 

of future communities

Designer evaluates changes 

in style and materials

Designer adds new features to 

production plans

Site Supervisors evaluate skills, 

subcontractors and code issues

Site Supervisors train crews 

and set clear expectations

Trades professionals implement 

best practices in their installation 

and construction processes

Offers design solutions based 

on whole building analysis, 

including materials compatibility 

and durability, and system 

tradeoff modeling 

Communicates design approach 

to supervisors and crew

Determines impact of design 

solutions, including energy savings

Provides test results and 

data for marketing

Observes construction practices 

and recommends improvements 

and offers training

Offers help with upgrading 

production plans and with solar 

and green community design

Conducts field tests and 

inspections including blower 

door, duct pressure, and HVAC 

system tests

*Icons correspond with chapters and company capabilities
Homeowners

Shopping for value, comfort, and quality

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-1

Comfort. Economy. Durability. Performance. Some homes force you to choose. 

Energy-efficient homes deliver it all. And as a homebuyer, you deserve, and should 

demand, the whole package.

One way to know you have found an energy-efficient home is to look for the 

ENERGY STAR® label. ENERGY STAR has taken much of the guesswork out of 

buying new homes and other products. ENERGY STAR-qualified new homes are 

built to strict energy-efficiency guidelines using proven technologies and construction 

practices. Your builder also may have incorporated other building features that go 

beyond ENERGY STAR criteria for even more energy savings, and for greater 

health and comfort.

ENERGY STAR features should be included in all houses from lower cost starters 

to high-end customs. This chapter gives you an introduction to the technology that 

makes these houses work, how much they cost, how to pay for them, and a checklist 

of what to look for in new homes. The features described here are specifically 

designed for the hot and humid climate found in the Southeastern United States.

You’re in Good Company

The companies that build ENERGY STAR homes are among the best and largest in 

the nation. Over 2,000 builders work with ENERGY STAR in the United States. 

And about 50% of the largest 100 builders in the nation have at least one division 

building ENERGY STAR 

qualified homes. Thousands 

of small companies also build 

ENERGY STAR homes. And 

many of these companies are 

working with Building America.

In addition to discussing the 

minimum requirements for 

attaining ENERGY STAR, 

this packet suggests other 

techniques developed within the 

U.S. Department of Energy’s 

Building America program. These 

techniques can help you avoid 

common construction problems 

that occur in the hot and humid 

climate. The recommendations 

in this chapter are based on 

Building America’s building 

science research on over 25,000 

homes in 34 states encompassing 

every climate region in the nation. 

QUICK TIPS | HOMEOWNERS

• Look for the ENERGY STAR label 

for government-endorsed proof that 

a home is energy efficient.

• Learn why an energy-efficient home 

is usually a higher quality home all 

the way around.

• Use the enclosed checklist to shop 

for energy-efficient homes.

• Use the nationally recognized HERS 

rating to know just how efficient the 

homes you are considering really are.

• Own a home you can be proud of 

—energy-efficient homes are good 

for the environment.
Homeowners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-2

Building America works with the nation’s premier building scientists to conduct 

research and share knowledge with builders to help build better homes. 

If you are looking for energy-saving features in your new home you’re in good 

company. Recent homebuyer surveys have found that energy efficiency is the top 

upgrade that homebuyers choose in new homes. And homebuyers in Phoenix rated 

energy efficiency as the number one reason related to the house itself in determining 

their satisfaction with the production builder recognized by Professional Builder

magazine as having the top customer satisfaction in the nation (2003). This same 

builder won the J.D. Powers and Associates top ranking for customer satisfaction in 12 

of 21 markets in the United States. The winner, Pulte Homes, is a Building America 

Partner that brands its homes using ENERGY STAR.

How Quality Houses Perform

You don’t want to spend the first several months in your new home fixing construction 

problems. Not long after unlocking a new home’s door for the first time comes the 

reality of keeping the house and its inhabitants happy and comfortable. You’ll save 

time, money, and personal energy when you buy a house that works from the start.

The building materials and quality that go into an energy-efficient home help to keep 

temperatures even, the air clean, and the house dry, quiet, and draft-free. The checklist 

near the end of this chapter provides details of what to look for in quality home 

construction. Figure 1 provides an overview of features Building America recommends 

to help you avoid problems, while saving time, money, and energy.

FIGURE 1: Hot & Humid Design Features

All of these features save energy. Read the descriptions at right to see what else they do.

Hot & Humid Design Features

A. Efficient Windows: help to control 

and reduce ultraviolet light that can fade 

carpets and furniture, helping to keep 

your belongings looking like new and 

keeping window areas cooler and more 

comfortable to sit near. Window flashing 

protects against water leaks.

B. Compact and Tightly Sealed Duct 

Runs: shorter runs mean less to go 

wrong and fewer air leaks to put air 

where it is intended to go with fewer 

contaminants like humidity and dust from 

attics or crawlspaces. Leaky ducts are 

a major contributor to mold problems. 

Return air ducts in every room ensure 

balanced air pressure for less drafts and 

more balanced temperatures throughout 

the house. Put ducts in conditioned 

space, if possible.

C. Right-Sized and High-Efficiency 

HVAC Equipment: costs less to install 

than bigger equipment, saves energy, 

and is designed to comfortably handle 

heating and cooling loads.

D. Ventilation: exhaust fans remove 

moisture and pollutants. A controlled, 

filtered air intake ensures pplenty of 

fresh air. A fresh air intake is not an 

ENERGY STAR requirement but it is 

recommended.

E. Dehumidifier: ensures that indoor 

humidity levels are kept at a comfortable 

level. This measure is not an ENERGY 

STAR requirement but is recommended 

by Building America.

F. Sealed Combustion Appliances: 

reduce moisture buildup and ensure 

the removal of combustion gases. 

We recommend against non-vented 

combustion appliances such as nonvented fireplaces or heaters.

G. Overhangs: provide shade and direct 

water away from the house. Overhangs 

are not required by ENERGY STAR but 

are a sign of thoughtful design. 

H. Insulation: holds comfortable 

temperatures in conditioned spaces and 

helps control noise. For insulation level 

recommendations visit www.ornl.gov/sci/

roofs+walls/insulation/ins_16.html

I. Air Sealing: stops drafts, helps keep 

humidity and garage contaminants out of 

the house, and creates a barrier to rodents 

and insects.

J. Well-Designed Moisture Barriers:

avoid expensive structural damage and 

help stop humidity, mold, and mildew.

K. Building System: Perhaps the best 

thing about buying a system-designed 

house is that all of the parts are designed 

to work together. This can save you 

money on the purchase price, and it also 

means a durable and comfortable system, 

one that will help avoid maintenance and 

repair costs down the road.
Homeowners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-3

An Energy-Efficient Home Will Cost You Less

As with any upgrade, precisely how much is paid for an energy-efficiency upgrade will 

depend on many factors. Some builders make energy-efficiency features part of their 

base price, so you pay no more additional cost. Others will sell you a specific upgrade 

package at a predetermined cost. Depending on how the builder structures his costs, 

the home’s size and design, and the prevailing cost of building materials, the additional 

cost of a system-designed energy-efficient home may range from zero to $1,500 or 

more.

But even if you pay more up front, the good news is you are likely pay less for an 

energy-effiicient house on a monthly basis, if you consider the cost of energy. Here’s 

an example showing why:

FIGURE 2: Monthly Cost Comparison

Our example assumes a base price on the house of $200,000, an upgrade cost of 

$1,500, and a 30-year mortgage at 6% interest. We also estimate that monthly energy 

bills will be about $135 after energy savings of about $40 per month in the energyefficient home.

Your builder, realtor, or lender should be able to help you work through the savings for 

your house based on actual features, costs, and interest rates.

Energy-Efficient Mortgages Can Help You Get More for your Money

Lenders recognize that owning an energy-efficient home makes financial sense and 

they have developed energy-efficient mortgages to encourage consumers to purchase 

these types of homes. The loans work by allowing consumers to borrow more than they 

would typically qualify for.

STANDARD HOME ENERGY STAR® HOME

$1,159 $1,168

$175

TOTAL MONTHLY = $1,334

TOTAL MONTHLY = $1,303

< MORTGAGE BILLS >

< ENERGY BILLS > $135

$31 MONTH

$372 YEAR

SAVINGS

“You don’t know the quality 

of life you can experience 

until you’re in one of these 

homes. Our quality of life has 

improved tremendously and 

we’ll realize energy cost savings 

for years to come.” 

John Russo, purchased an ENERGY 

STAR home in 2002, as quoted in the 

Boston Herald, December 6, 2002.

According to the U.S. 

Environmental Protection 

Agency, which manages the 

Energy Star program with the 

U.S. Department of Energy, 

100,000 new homes have 

now earned the Energy Star 

designation, saving these 

homeowners a total of $26 

million in energy costs 

every year.
Homeowners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-4

The following features for energy-efficient loans are taken from Fannie Mae, the 

nation’s largest source of funding for mortgages. You can learn more about Fannie Mae 

at www.fanniemae.com.

• Energy-efficient mortgages (EEM) are available for both purchase and 

refinance in conjunction with most Fannie Mae first mortgage products, 

including conventional fixed-rate and adjustable-rate mortgages. 

• Monthly savings resulting from energy efficiency can be used to qualify 

borrowers for a larger mortgage. This means consumers can buy more home 

in the form of energy efficiency or other upgrades.

• The EEM can be used with many Fannie Mae mortgage products. The 

guidelines of the selected Fannie Mae mortgage apply, with the EEM allowing 

for the projected energy savings to provide an adjustment to the loan-to-value 

and qualifying ratios that favor the borrower.

• To qualify, you must obtain a Home Energy Rating System (HERS) report, 

which provides a rating of the energy efficiency of the home and estimates the 

resulting cost savings using average utility 

rates and usage data. See What’s the 

Score? below for more information 

on HERS. Building America 

recommends that every 

home receive this type 

of rating and many 

ENERGY STAR 

homes were rated 

in order to qualify.

What’s the Score?

The Home Energy Rating System (HERS) is a nationally recognized method of 

evaluating a home’s energy performance. Rating professionals are people trained 

in preparing HERS scores and accredited by the Residential Energy Services 

Network, found on the web at www.natresnet.org.

A house built to the 1993 Model Energy Code has a HERS score of 80. This 

is considered a base house for a HERS comparison. Each one-point increase in 

the score equates to a 5% increase in energy efficiency in heating, cooling, and 

water heating. The homes described in this document are similar to ENERGY 

STAR homes and must be at least 30% more efficient than the base house and so 

would have a HERS score of at least 86. In some states, greater HERS scores are 

required because of stringent current building codes.

HERS scores can be used to compare across houses even if the houses differ in 

design, size, or type of HVAC equipment. Even if homes are not participating in 

labeling programs like ENERGY STAR, the HERS score can be used to gauge 

energy efficiency. See the Designers section for more information on HERS.

FIGURE 3: HERS Score
Homeowners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-5

Consumers using Federal Housing Administration (FHA) loan insurance should 

consider FHA’s Energy Mortgage Program. This program helps borrowers to 

include energy-efficiency features in their home by stretching the size of the 

loan they may qualify for without increasing their down payment. An energyefficient mortgage is one of many FHA programs that insure mortgage loans. FHA 

encourages lenders to make mortgage credit available to borrowers who would not 

otherwise qualify for conventional loans on affordable terms (such as first-time 

homebuyers) and to residents of disadvantaged neighborhoods (where mortgages 

may be hard to get). To learn more about FHA programs visit the web site at 

www.hud.gov/offices/hsg/sfh/eem/energy-r.cfm.

Some builders are working with lenders to offer special mortgage terms, such as a lower 

interest rate, to help buyers of energy-efficient homes. Ask your builder if they have any 

special programs.

Guaranteed Energy Costs and Comfort 

Some builders go even further than doing a great job of constructing an energyefficient home. Some guarantee it. Builders who guarantee their homes are willing to 

tell buyers how much energy the home should use, and they guarantee these levels will 

not be exceeded. These guarantees are backed up with payments if limits are exceeded. 

Builders can work with insulation companies or other partners to offer guarantees or 

caps on their home’s energy costs, or they may develop their own programs. Some 

cover room comfort by guaranteeing that the temperature at the thermostat will not 

vary by more than 3 degrees at the center of any room served by that thermostat. A 

Building America team helped to develop these programs. Information on three of 

these programs can be found at:

• Environments for Living – www.eflhome.com/index.jsp

• Engineered for Life – www.us-gf.com/engineered.asp

• The Energy Use and Comfort Guarantee –

www.artistichomessw.com/guarantee.htm

And There’s More – More Green for You and More Green for the Planet

Where else can you find an investment that delivers monthly dividends, makes 

you more comfortable and your house more durable, comes with its own financing 

incentives, and may even have guaranteed energy performance? ENERGY STAR 

homes give you all this, plus they are good for the environment. Just one ENERGY 

STAR qualified new home can keep 4,500 pounds of greenhouse gases out of our 

air each year.

Last year, thanks to programs like Energy Star and other energy efficiency measures, 

Americans cut their energy bills by more than $7 billion, along with saving enough 

energy to power 15 million homes. The greenhouse gas emissions saved by these steps 

was the equivalent of taking 14 million cars off our country’s roads. Visit the ENERGY 

STAR web site at www.energystar.gov to learn more about how ENERGY STAR is 

helping the environment.

Just one ENERGY STAR 

qualified new home 

can keep 4,500 pounds 

of greenhouse gases out 

of our air each year.

“Knowing that 100% of our 

homes exceed the minimum 

standards makes a statement to 

our buying public that we are 

confident this is the way of the 

future and not a fad or style.” 

Andrew Nevitt, Architect, Medallion 

Homes, San Antonio, Texas
Homeowners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-6

What to Look For

Take the Homebuyer’s Checklist at the end of this chapter with you when you’re 

shopping for a new home. Ask your builder or salesperson to help you consider each 

item. For a more detailed checklist, go to Appendix I. You may want to ask to see 

houses under construction to see how some measures are installed. The builder or 

realtor may have models and displays to help you see other features. Not all of the 

measures will apply to every home (for example, homes don’t typically have more 

than one kind of heating system). Check the features that are most important to you. 

We’ve left some blank spaces at the end of the checklist in Appendix I so you can fill in 

features that you want to remember to check that may or may not be energy related.

If You’re Building a Custom Home

A great advantage to building a custom home, or ordering your home before it is built, 

is that you can work with your builder or designer to get the features you want. Give 

your builder or designer this Best Practices Guide. It contains everything they need to 

design and build a durable and comfortable energy-efficient home.

Sources & Additional Information

• J.D. Power and Associates. J.D. Power and Associates 2003 New Home 

Customer Satisfaction Study. West Lake Village, California. 2003.

• Johnston, David. 2001. “Buyer Green.” Housing zone.com. 

www.housingzone.com/topics/pb/green/survey/buyer.asp#
Homeowners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • HOM-7

Homebuyer’s Checklist

Use the following checklist to compare house features in different homes you visit. 

A more detailed checklist is available in Appendix I.

MEASURE Building 

America 

Builder

#1

Builder

#2

Builder

#3

BUILDER SERVICES AND RATINGS

ENERGY STAR Rated Yes

HERS Score of 86 or greater Yes

Energy Performance Guarantee Good Idea

Energy Efficient Mortgage Good Idea

Provides Owners Manual Yes

If you can answer yes to the above questions you will have a good energy performing home. 

Note that in some states, due to more aggressive energy codes, ENERGY STAR may require 

HERS scores greater than 86. 

VENTILATION

Controlled fresh air provided in the house Yes

Quiet Exhaust vents in bathrooms Yes

Quiet Exhaust (not recirculating) 

vents in the kitchen Yes

Supply and return air vents in 

each room Yes

WINDOWS

Windows flashed to help repel water Yes

Windows rated .35 U-factor and .35 SHGC* Yes

COMBUSTIONS APPLIANCES

Combustion appliance exhausts vented 

to the outside (except ovens) Yes

Hardwired carbon monoxide monitors 

included for every 1000 square feet of 

living space if combustion appliances 

or an attached garage are present 

Yes

DEHUMIDIFIER

Dehumidifier present or the house 

has been designed so one can easily 

be added

Yes

MORE TO LOOK FOR TO ENHANCE ENERGY EFFICIENCY

ENERGY STAR qualified light fixtures Good Idea

ENERGY STAR qualified refrigerator Good Idea

ENERGY STAR qualified dishwasher Good Idea

ENERGY STAR qualified clothes washer Good Idea

ENERGY STAR qualified dehumidifier Good Idea

*Solar Heat Gain Coefficient
Managers

Putting building science to work for your bottom line

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MNG-1

This document tells company leaders how to use proven technologies and a successful 

marketing program to gain competitive market advantage and improve your 

company’s economic and product performance. A more efficient home can mean 

a faster return on your investment

An Invitation to Building Company Managers

We invite you to use the information in this 

packet to lead your company to increased profits 

and greater customer satisfaction. Building 

America is a Department of Energy (DOE) 

program that has sponsored building science 

research on 25,000 homes nationwide. These 

technologies and the Building America systems 

approach can set your company apart, giving 

you a considerable competitive advantage in 

how you design, build, and sell homes.

Building America

Building America works with the nation’s premier building scientists to conduct 

research and bring knowledge to builders to help them build better homes. This 

knowledge has been gained from private/public partnerships involving builders all 

over the country. The program is sponsored by the U.S. Department of Energy. 

Many builders have adopted the program’s principles and improved the performance 

of their houses and companies. Over 250 builders and venders have partnered with 

Building America, including five of the largest 10 builders in the nation. This best 

practices guide contains results from this research in a form that your company can 

immediately build into your homes to increase efficiency, comfort, and durability.

QUICK TIPS | MANAGERS

• The smartest builders in the industry are working with Building America.

• Applying the Building America Process can: cut your production costs, 

reduce risks, improve your bottom line, help make you a market leader, 

and turn your customers into lead generators.

• This document gets you and your company started.

• ENERGY STAR® can help you market your new and improved product.

“I’m very positive about 

Building America. We are 

taking an approach of wanting 

to build a better product in 

all areas—energy efficiency, 

indoor air quality, no moisture 

problems, and one that is 

sensitive to the environment.” 

GW Robinson, 

President of GW Robinson
Managers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MNG-2

FIGURE 1: A small sampling of Building America’s 250 partners

Building America Partner Ranking among Top 100 Builders

Pulte Homes 2

Centex Corp 4

The Ryland Group 7

Beazer Homes USA 8

K Hovnanian 9

Shea Homes 12

Habitat for Humanity International 16

Weyerhaeuser Real Estate Company 17

The Business Case for Building Science and Energy Efficiency

Why are all these builders working with Building America? The answer is simple - 

Working with Building America can enhance your company’s bottom line through:

• Cost savings from making the best materials and equipment choices

• Reduced risks, increased productivity, and fewer callbacks

• Greater profit margins on energy efficiency and other upgrades

• Competitive advantage in the marketplace

• Customer satisfaction and referrals.

More information on each of these points is presented below. But boosting the bottom 

line isn’t the only reason builders build quality, efficient homes. Builders tell us it 

boosts their pride in their craft, increases the morale of their workforce, and gives 

them a good feeling at the end of the day, knowing they’re doing their part to help 

the environment.

Properly Choosing Materials and Equipment

Building science offers many tools to help you pick out the right materials and size 

them correctly, and to help make sure you are using them to build the right product. 

Explanations and suggestions on building systems, designs, and trade-offs are in the 

Designers chapter of this document. The costs of some measures can be more than 

what you are currently spending. The idea is to use the materials best suited to the job 

and to size equipment accordingly. Higher prices in one area can be at least partially 

offset with savings in other areas. Costs for all building materials can vary tremendously 

in their own right, but your level of experience and design choices have a large bearing. 

For comparison, some builders find they experience no overall increase in materials 

costs to offer an energy-efficient package, but others suggest added costs of up to 

$1,500 per home. In the Designers chapter, we show one example of costs and savings 

that resulted in a total additional cost of about $300 on average for the design used by a 

Building America partner in the hot and humid climate. Read on to find out how this 

investment can add to your bottom line.

“The biggest benefit is the 

sense of satisfaction of doing 

something good. We’re 

conserving the environment 

and providing a better product 

to our buyers.”

Lucian Kragiel, Co-owner of 

Atlantic Design and Construction 

“I owned a private construction 

firm for 30 years before I 

retired and joined Habitat. I’d 

say, with the Building America 

practices we’re using, these 

homes are better built than 

what I built before—and I was 

building houses up to a million 

dollars or more and I thought I 

was building well.” 

Walter Hendrix, Executive Director 

of Troupe Chambers Habitat 

for Humanity and Dependable 

Affordable Sustainable Housing 

for La Grange

“There is a sense of pride in 

knowing that Medallion 

Homes takes the extra effort 

in research and production to 

deliver the best product for 

the price. ” 

Andrew Nevitt, Architect, Medallion 

Homes, San Antonio, Texas
Managers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MNG-3

Reduced Risks, Increased Productivity, and Fewer Callbacks

These benefits follow closely from selecting and properly using the right materials and 

equipment. Making a change in your process may take extra time the first few times 

you try it, but once established, the payoffs can be significant.

One of the great values of using Building America approaches is that they were 

designed to solve construction problems, such as moisture degradation and mold 

growth, that plague builders. More than 10,000 mold cases are now pending 

nationwide, with an increase in cases of more than 300% since 1999 (Insurance 

Information Institute as reported in Wood and Clift, 2003).

Applying building science reduces the risk of big problems and helps to eliminate the 

more mundane defects that cost money to fix. If you reduce the time your crews are 

working on call backs, you increase the time they can be working on new product.

From an Economic Standpoint, Everyone Wins

As a manager, watching your profit margins is a full-time job. The structure of your 

business and emphasis you place on consistency determines how much profit you get 

from options packages. Some builders choose to incorporate energy efficiency and 

health and comfort options into their base price; others include them as options with 

a profit margin similar to other premium add-ons. Whichever approach you use, 

the experience of other builders suggest that customers place great value on energy 

efficiency and will pay to get it.

Profit margins vary substantially from company to company. A National Association 

of Homebuilders report (1999) and Professional Builder magazine (2003) suggest a net 

profit margin of about 10% on overall house construction. This number is consistent 

with publicly traded homebuilding companies. Six companies’ annual financial reports 

to the Securities Exchange Commission over 2001 and 2002 reported net profit 

margins ranging from 4.2% to 9.6%. Gross profit margins over this same time period 

ranged from 7.4% to 19.2%. In comparison, builders report they have gained about a 

30% profit margin on efficiency upgrade packages. 

In the Homeowners chapter, we offer an example showing how energy-efficient 

homes end up costing less for consumers on a monthly basis when both the mortgage 

and energy expenses are taken into account. Consumers can either pocket these lower 

costs or use them to buy a more expensive home. Any upgrades translate into 

added profit.

In short, builders can increase their profits at the same time that consumers lower 

their costs. From an economic standpoint, everybody wins.

Customer Satisfaction and Referrals

Customer satisfaction matters to your company’s future and energy efficiency matters 

to your customers. Pulte is a Building America Partner that brands its homes using 

ENERGY STAR. J.D. Power and Associates, a market research firm, gave Pulte’s 

various divisions top rankings in 12 of the 21 U.S. markets it surveys, including Houston, 

Palm Beach, and Tampa Bay, and placed it among the top 3 companies in 17 markets.

“Building America’s technical 

assistance on building science 

helped us to reduce callbacks by 

70% in our Chicago Division. 

That’s a tremendous savings for 

our company and means our 

customers are happier 

with their homes.” 

Frank Beasley, V.P. of Building 

Science, Town and Country Homes.

“Since partnering with Building 

America in 2001, Artistic 

Homes reports that its liability 

for defects and damage has 

been reduced, as has the 

number and cost of warranty 

calls; ‘meanwhile, customer 

satisfaction is at an all-time 

high,’ according to Max Wade 

of Artistic. The production 

builder has produced more than 

2000 Energy Star homes in 

Albuquerque, NM, since 2001.”

As reported in Builder Magazine 

11/1/03

“We offer ENERGY STAR 

as an upgrade, but everyone 

chooses it. We have 100% 

participation so all of our 

homes are ENERGY STAR.” 

Lucian Kragiel, Co-owner of 

Atlantic Design and Construction.
Managers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MNG-4

Pulte Phoenix, which J.D. Powers ranked first in that local market, also won the 

Diamond Award from Professional Builder Magazine and NRS Corp., a market research 

company that works with the home building industry. Pulte had the top customer 

satisfaction for production builders of nearly 300 builders in the nation. 

Paul Cardis of NRS, a market research expert, notes that “customer satisfaction is 

important for many reasons, not least is that satisfied customers refer future customers 

and the conversion rate for referrals is twice that of non-referred shoppers.”

Consumers Expect More

Buyers want energy efficiency and 

they are willing to pay for it. A 2001 

Professional Builder Magazine survey 

found that energy efficiency is the 

number one upgrade that homebuyers 

seek in a new home. Nearly 90% of new 

homebuyers in the survey were willing 

to spend more for energy efficiency 

features (Johnston 2001). Consistent 

with this study, the NAHB found that 

consumers would be willing to spend up 

to $5000 more on a new home if it saved 

them $1000 on their annual utility bills 

(NAHB 2002). And Pulte’s customers 

in Phoenix rated energy efficiency as the 

most important product-related reason 

for referring their contractor to new buyers.

Competitive Advantage in the Marketplace

One of your key goals as a manager is to gain competitive advantage in the marketplace. 

The technologies described in this packet can give your company a technological edge. 

One easy way to tell the public about your new product is to partner with ENERGY 

STAR. ENERGY STAR is a nationally recognized branding program sponsored by 

the U.S. Department of Energy and the U.S. Environmental Protection Agency. 

Consumers trust the ENERGY STAR logo to tell them whether their product is 

energy efficient. Participating in ENERGY STAR is easy and it gives you an effective 

way to distinguish your product from your competition’s. Over 2,000 builders work 

with ENERGY STAR in the United States. And half of the 100 largest builders in the 

nation have at least one division building ENERGY STAR qualified homes.

ENERGY STAR qualified homes are independently verified to be at least 30% more 

energy efficient in space conditioning and water heating than homes built to the 

1993 national Model Energy Code or 15% more efficient than the state energy code, 

whichever is more rigorous. These savings are consistent with the practices described in 

this best practices manual. Heating, cooling, and hot water energy use make up about 

half of a household’s total utility bills. 

The September 2003 issue 

of Professional Builder

provides six top reasons 

why customers are willing 

to recommend a builder. 

Energy efficiency is first 

among the reasons related to 

product.

Nearly 93%

of buyers of Pulte Homes in 

Phoenix had made at least one 

positive recommendation.

Professional Builder Magazine, 

September 2003, p. 67

“Our attention to energy 

efficiency is what really makes 

Pulte’s homes stand out.” 

Les Woody, Pulte Phoenix 

Director of Customer Service

Atlantic Design, a Building America partner, was recognized as a 2000 EPA Builder 

of the Year for its quality energy-efficient 

construction.
Managers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MNG-5

Take the Next Step

This information packet is designed to give your company all the information you need 

to start using the Building America systems approach in the hot and humid climate. 

The techniques described will help you avoid many of the problems plaguing all 

builders in hot and humid climate.

Make sure your team reviews the sections prepared for each of your company’s 

capability areas: marketing, site planning, design, building site supervision, and the 

trades. This information will help your company compete in an increasingly complex 

and risky market. Following the design practices discussed in the Designers 

chapter and the inspection and testing procedures outlined in the Site Supervisors

chapter will give you the technical information you need to build your business. Find 

more information on ENERGY STAR in the Marketers chapter and on the web 

at www.energystar.gov.

Case Studies

Take a look at the case studies at the end of the book. All offer examples of how 

builders achieve energy efficiency. Two of the studies offer a comparison in 

management style. These case studies show builders that companies can either climb 

stares, one step at a time, or jump on the elevator and push the button for the top floor. 

Both approaches will get you to your destination.

Compare Atlantic Design and Construction’s case study with their neighboring builder, 

G.W. Robinson. Both companies build high value homes in the Gainesville, Florida 

area. A subtle difference between these companies is in how they got to the point 

of building highly efficient homes. Atlantic adopted changes to their base practices 

over time, first just meeting ENERGY STAR requirements (HERS 86), then taking 

several steps to reach HERS ratings of 89 and 90. Robinson took more of a makeover 

approach. Robinson also builds homes resulting in HERS ratings of 89 and 90, but 

made the innovations to do so all at once. Both management approaches are valid and 

both have resulted in profitable companies building great houses.

Sources & Additional Information

• National Association of Home Builders. The Truth About Regulatory Barriers. 

Washington, D.C. 1999.

• Professional Builder. “Where are the Giants Headed? Industry Consolidation 

is Changing the Way Even the Smallest Production Builders Do Business, but 

How Far it Will Go is Still Open to Debate.” April 2003.

• J.D. Power and Associates. J.D. Power and Associates 2003 New Home 

Customer Satisfaction Study. West Lake Village, California. 2003.

• Professional Builder. “Customer Service Standard Setters.” September 2003.

• Wood, C., and L. Clift. “Seven Wonders of the Construction World.” 

ProSales. October 2003, pp. 28-44. 
Marketers

Energy Efficiency Delivers the Value that Customers Demand

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MKT-1

By selling homes you bind your company to its customers. Your work enables the 

company to capitalize on the benefits of its investments, including those made 

in energy efficiency. And you are the ones who help homeowners understand the 

quality, value, and economy represented by your product.

ENERGY STAR Qualified Homes: Telling Your Story

An easy way to sell energy-efficient homes is to become an ENERGY STAR® partner. 

Even if you build or sell great houses, if they aren’t ENERGY STAR qualified, it’s 

hard for your customers to know how much efficiency they are getting. ENERGY 

STAR helps you to tell your story. The ENERGY STAR logo makes it easy to tell 

consumers you are selling a superior product. And the ENERGY STAR program 

offers much in the way of advice and examples of how to use the logo. Differentiate 

yourself by offering a home that is certified to be more efficient—and better for the 

environment—than standard models.

To find out more about marketing with the 

ENERGY STAR logo visit the program’s 

web site at www.energystar.gov. You’ll find 

information about before-sales marketing, 

point-of-sale techniques, and building 

ongoing relationships with your customers. 

Much of the information comes from 

successful techniques used to sell ENERGY 

STAR homes across the nation. Tools on 

the website will help you instantly craft 

your message and prepare sales materials.

ENERGY STAR offers a marketing platform 

that home builders can use to recognize that 

you offer truly energy efficient homes.

QUICK TIPS | MARKETERS

• Energy efficiency, and the quality that comes with it, gives you a 

competitive advantage.

• ENERGY STAR can help you capitalize on your competitive advantage, 

produce marketing materials, and connect with buyers.

• Your customers see energy efficiency as a sign of value.

• Some of the biggest builders in the country have learned that energy 

efficiency can turn existing customers into new sales leads through 

customer satisfaction.

• Learn how industry leaders sell new energy-efficient homes.
Marketers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MKT-2

Increase Customer Satisfaction and Let Your Customers Sell Your Product

Wouldn’t it be great if, for every home you sold, you could add a new sales associate 

to your staff to sell even more?

That’s what energy efficiency can do for you. Happy customers will sell your products 

for you. And energy-efficient homes make happy customers. Compared to standard 

homes, energy-efficient homes cost less to own, are more comfortable to live in, and 

require less maintenance.

The builder with the top customer satisfaction rating in the nation, Pulte Homes of 

Phoenix, is a Building America partner offering ENERGY STAR qualified homes. 

Pulte’s Phoenix division has had one or more positive referrals from 93% of its 

homebuyers. The conversion rate for shoppers referred in this way is twice that of 

non-referred shoppers. Homeowners talk, and word of mouth is a powerful selling 

tool. Some experts, in fact, say word-of-mouth is the most effective selling tool because 

it carries with it the credibility of a 

trusted third party, such as a friend 

or relative. Add to that the fact that 

many potential buyers are skeptical 

of traditional advertising, and it’s 

no surprise that 10% to 30%, and 

sometimes more, of builders’ sales 

come from referrals (Farnsworth 

2003). The best way to sell homes is 

to let your customers do it for you. 

See the Managers chapter for 

information on the great customer 

satisfaction ratings received by 

builders selling ENERGY 

STAR homes.

Sell the Value that Home Buyers Expect

Market research shows:

• Energy efficiency is the number one upgrade sought by homebuyers 

of new homes (Professional Builder Magazine 2001)

• Nearly 90% of new homebuyers are willing to spend more for 

energy efficiency (Johnston 2001 and NAHB 2002)

• Buyers rate energy efficiency as a home builder’s most important 

product-related reason for referring new customers (Professional 

Builder Magazine 2003)

How Industry Leaders Sell Energy-Efficient Homes

The NAHB Research Center sponsors an annual award competition called the 

Energy Value Housing Award. The Center has compiled the winning builder’s 

“Tell other builders—it’s easier 

to do than they think. People 

really want ENERGY STAR 

if they understand it. They 

(the builder) can make money 

doing it. They can feel better 

about themselves at the end of 

the day by making the planet 

healthier, by building 

better homes.” 

Lucian Kragiel, Co-owner of 

Atlantic Design and Construction 

“If you don’t tell your story, 

you give it away!”

Vern McKown, President Ideal Homes

Shoppers love to peer into the attic through this 

viewing window in a Building America model house 

by Cambridge Homes. Shoppers can see the special 

insulation, and the thermometer tells them how cool 

the attic stays.
Marketers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MKT-3

marketing techniques into a document that can be purchased on the web at 

www.nahbrc.org/tertiaryR.asp?CategoryID=1705&DocumentID=3404 (Sikora 2002). 

Here are some of the best practices recommended by the NAHB Research Center and 

other sources:

• Educate customers and sales professionals. Show buyers how living in 

an energy-efficient home will benefit them with lower household costs. 

The ENERGY STAR Web site has an example as does the Homeowners 

chapter. Vital to customer education is an informed sales staff and team of 

local sales professionals.

• Walk-throughs and model homes can be invaluable educational tools for 

both buyers and sales staff. Model homes with display cutaways of energy 

features such as insulated attics and wall sections help them understand the 

energy-efficient construction process. Use labels, flags, and banners to create 

a fun self-explanatory message to give buyers a focus while they drive or 

walk the development. Recent research suggests just how important model 

home, models of house features, and other educational tools are to shoppers 

(Farnsworth 2003).

• Training sessions can be an effective tool for educating sales staff and 

professionals. Use slides, sample products, and energy bills as aids.

• One way to educate consumers is to emphasize an energy-efficiency upgrade 

when signing the final papers. One builder has a wall of testimonials, photos, 

and utility billing history in his waiting room. All prospects are given an 

opportunity to view this “wall of fame” before the final sale is made. Another 

builder has the buyer meet with the building site supervisor after the sale is 

made. This person gives them one more chance to sign up noting, from a 

builders’ perspective, what a better house they will get (Rashkin 2002). 

• Publications are an educational tool that customers and sales professionals can 

take home. Develop your own brochures or books or give away reprints of 

magazine articles, ENERGY STAR brochures, or Building America brochures. 

Don’t overlook vendors and trade associations. They can provide excellent 

materials, often at no charge. For example, excellent information on window 

performance is available at the Efficient 

Windows Collaborative web site at 

www.efficientwindows.org/index.cfm. 

Also, give potential buyers a checklist 

so they can compare the energy saving 

measures in your homes with those of 

other builders. A sample is included 

in the Homeowners chapter.

• Advertising can be used to explain the energy-efficiency advantages and 

distinguish builders from their competition. The ENERGY STAR website 

has useful information for designing advertising.

• The Internet and compact disk formats are another forum for presenting all 

of your education and advertising messages. Some marketers suggest that all 

builders should have a web site, even if it is simple and offers only limited 

information. CDs with brochures or slide shows can be given to potential 

buyers to take home and replay your message.

“It’s not hard to sell when you 

educate the buyer if you can 

show them (the buyer) that 

they will get lower utility 

bills. And they are also going 

to get a higher resale value on 

their house. ENERGY STAR 

is becoming increasingly well 

known. Builders who don’t 

do it will lag behind.” 

Lucian Kragiel, Co-owner of 

Atlantic Design and Construction
Marketers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • MKT-4

• Seek out free publicity. Nothing is more cost effective than sending a news 

release to local media to announce business news and other company activities. 

News releases can cover your company’s involvement in educational activities, 

for example, teaching school children about energy efficiency or other 

charitable actions.

• Offer energy-efficiency guarantees. Energy performance guarantees can 

help convince buyers that energy savings are real. Partnerships with outside 

companies can help to establish guarantees. For example, some insulation 

manufacturers offer home inspections, tests, and cost guarantees. The 

insulation company takes on the risk of covering the guarantee.

• Make buyers aware of energy-efficient mortgages.

• Take advantage of the testing data available on your homes. If your company 

follows the best practices in this guide, you will have blower door and duct 

pressure test data and a HERS score to share with buyers. Use these data to 

inform your customers and differentiate your houses.

Participate in ENERGY STAR and other partnerships. ENERGY STAR and Building 

America can provide technical guidance through publications and their Web sites. 

Partnering with ENERGY STAR cements your company’s commitment to energy 

efficiency and gives you access to the ENERGY STAR brand.

Sources and Additional Information

• Farnsworth, Christina. 2003. “The Weakest Link.” Builder Magazine, 

December 2003. www.builderonline.com/article-builder.asp?channelid=55&ar

ticleid=375&qu=consumer+survey

• Johnston, David. 2001. “Buyer Green.” Housing zone.com. 

www.housingzone.com/topics/pb/green/survey/buyer.asp#

• Laquatra, Joseph. 2003. “The Value of Energy Efficiency.” Home Energy, 

November/December 2003. www.homeenergy.org

• National Association of Home Builders. 2002. What 21st Century Home Buyers 

Want. NAHB, Washington, D.C.

• Rashkin, Sam. 2002. “Surprise! Energy Efficiency Sells without Rebates: 

Results of Mainstream Builders Selling ENERGY STAR Labeled Homes” 

Proceedings of the 2002 ACEEE Summer Study on Energy Efficiency in Buildings, 

Washington D.C.

• Sikora, Jeannie. 2002. Energy Value Housing Award Guide: How, Build and 

Profit with Energy Efficiency in New Home Construction. National Association 

of Home Builders Research Center, Upper Marlboro, MD.
Site Planners

Properly situated homes pay big dividends

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • PLN-1

MANAGERS

Putting building science to 

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS 

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast 

and easy installation

MARKETERS

Energy efficiency delivers the 

value that customers demand

HOMEOWNERS

Shopping for value, 

comfort, and quality

The National Association of Home Builders (NAHB) estimates that 1.6 million new 

homes will be built each year over the next decade (NAHB 2002a). How these new 

developments are designed will have a major impact on energy use, the environment, 

and customer satisfaction.

Developers and site planners can set the stage for efficient communities and can 

direct builders to protect a community’s value through quality building practices.

The sun is the main source of heat in all homes. By looking at how houses receive 

sunlight, site planners can help optimize how much solar energy is available to heat 

a house, and how much heat must be removed with air conditioning.

In the hot and humid climate, planners should do all they can to avoid the entry 

of solar energy into houses, especially in summer. Site planners have two important 

tools to help avoid solar heat gain: lot orientation and shade trees.

Lot Orientation

As planners map out lots and roads, the relationship between buildings and the sun 

should be key. Just as you lay out roads to allow houses to take advantage of great 

views, or to work around hillsides and other landscape features, also consider how 

road design, lot lines, and orientation will influence the way that houses face the sun.

Lot lines and roads should be situated to minimize home exposure to east and west. 

These orientations provide the greatest solar heat gains. Plan your subdivision so 

that the longer sides of the houses will face north or south. Single-family homes tend 

to have longer fronts and backs and narrower sides, so lots facing north or south 

are preferred. Streets should be positioned in an east-west direction. The Florida 

Solar Energy Center (FSEC – see additional resources below) estimates that proper 

orientation can result in substantial savings of heating and cooling costs, depending 

on specific site conditions and house designs. Highly efficient houses, especially when 

good windows are used, are less dependent on orientation and shading to manage 

solar gain. With proper 

planning, there may be no 

added costs to the builder for 

good orientation.

When the house has clear 

single glazing, which is not 

recommended, interior 

shades, overhangs and typical 

combinations of shading 

devices significantly reduce 

energy costs. Naturally, a 

completely shaded house has 

the best performance in a 

hot climate.

QUICK TIPS | SITE PLANNERS

• Lots facing north or south are preferred 

to manage heat gain from the sun, so 

position streets to run east and west.

• Preserve trees for shade and breezes.

• Take advantage of natural breezes 

from lakes, the ocean, or other 

geographical features.

• Properly grade your development to 

take water away from structures.

• Use sustainable building practices.
Site Planners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • PLN-2

Shading is not nearly as 

important when windows 

with a low solar heat gain 

coefficient (i.e., SHGC 

of 0.35 or less) are used. 

Using a low-solar-gain lowE coating results in great 

energy cost reductions for 

all conditions even with no 

shading. This is because 

the glazing itself provides 

the necessary control of 

solar radiation, so these 

additional measures 

become less important 

in terms of energy use. 

For a description of the 

interactions between 

window performance and 

shading, see the Efficient 

Windows Collaborative 

Web site at:

www.efficientwindows.org.

Lot orientation is especially important if solar heating or electric generation systems are 

planned. Inexpensive tools can help assess how much solar energy will be blocked by 

obstacles on a particular site. Low-cost tools for solar assessments are described in the 

Designers chapter in the section about windows.

In addition to helping manage the sun and providing a marketing advantage, proper 

street design can reduce the environmental impacts of runoff, encourage walking and 

bicycling, and discourage speeding by through-traffic.

Subdivision planning can also help to gain cooling benefits from the wind. Houses and 

other buildings that are tightly packed may create a wake in the wind that is four to five 

times the buildings’ eave height.

Curved streets and staggered lots can assist in preventing wind disturbance. Trees 

can help to keep breezes cool as described in the next section. Taking advantage of 

breezes will reduce cooling costs. Wind conditions at any individual site may differ 

considerably from regional averages. Local geography such as ocean beaches, lakes, 

fields, golf courses, parks, and malls can influence local breezes.

Wind Wake of a Typical House

8'

FIGURE 2: Wind wake of a typical house

Source: Viera et al. 1992. p.3-7

FIGURE 1: Plan subdivision lot lines and roads for 

predominantly north and south orientation

Source: Viera et al. 1992. p.3-5

N

N

Subdivision with Predominantly

North- and South-Facing Sites

Typical Subdivision

N

OR

S
Site Planners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Shade Trees

Tree preservation brings many benefits, one of which is increased salability. Native trees 

are most beneficial to the environment. The NAHB reports in its survey of buyers, 

What 21st Century Homes Buyers Want, that over 80% of respondents in the South 

rated trees as essential or desirable (2002b, page 61). In 1992, the Florida Solar Energy 

Center (FSEC) estimated that a treed lot may increase the value of a home by as much 

as 20%. American Forests and the NAHB (1995) found that mature trees may add 

from $3,000 to $15,000 to the value of a residential lot.

Trees also bring value by providing shade. It is far better to prevent solar energy from 

reaching a house than to attempt to manage it once it enters. Deciduous shade trees 

block summer sunlight before it strikes windows, walls, and roofs, dissipating absorbed 

heat to the air where it can be carried away by the breeze.

Truly cool neighborhoods have trees. A study in Florida has shown that a subdivision 

with mature trees had cooler outside air with less wind velocity than a nearby 

development without trees (Viera et al. 2000). The development with a tree canopy had 

peak afternoon temperatures during July that were 1.1oF to 3.1oF ( ± 0.7oF) cooler than 

the site without trees. The total effect of shading, lower summer air temperature, and 

reduced wind speed can reduce cooling costs by 5% to 10% (McPherson et al. 1994).

Trees are most effective when located next to windows, walls, and air conditioners, 

and when located on the side of the home receiving the most solar exposure. Shade 

to the southwest and west is especially important for blocking peak solar gain in the 

summer in late afternoon. Trees more than 35 feet from the structure are probably too 

far away for shade.

N

Shading of

Air Conditioner Area

Deciduous

Trees

Shrub Shading of

Lower Wall

Windbreak Shrubs

North Side Shading from Evening and Morning Sun

Peak Load

Landscaping

FIGURE 3: Configuration of shade trees

Source: Viera et al. 1992. p.3-8
Site Planners

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Other Steps

In addition to orientation and the use of trees, many other steps can be taken during 

site planning to make developments user and earth friendly.

Site Grading

Proper site grading directs surface water away from building foundations and walls. 

The steeper the slope away from the building, the better the water will drain. Floor 

levels should always be above the surrounding grade. Basement floors should be higher 

than the surrounding drainage system. Driveways, garage slabs, patios, stoops, and 

walkways should all drain away from the structure. See EEBA’s Water Management 

Guide (Lstiburek 2003) for more information. Additional information on moisture 

management is also available in the Designers chapter.

“What we tell buyers is that 

we sell value...it’s about high 

standards in every aspect of 

home building...The whole 

idea is to get builders all over 

the country more concerned 

about building this way—it’s 

about energy efficiency, indoor 

air quality, waste recycling, 

water recycling, better 

planning—it all leads to 

better development.” 

GW Robinson, 

President of GW Robinson 

Source: Lstiburek, J.W. 2003. p.4

FIGURE 4: Drain all water away from the structure

Drain Wall

Drain Roof

Drain Building

Drain Site

Drain Ground Drain Ground

Drain Site

Drain Materials

Drain Components

Drain Openings
Site Planners

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • PLN-5

Sustainable Development

Builders who choose to advertise their “green” designs have found that buyers are 

willing to pay for environmental features.

Features that help to conserve the natural environment can include:

• Orienting lots to best manage energy and light from the sun.

• Land planning that preserves the natural environment and 

minimizes land disturbance.

• Site design that minimizes erosion, paved surfaces, and runoff.

• Preserving and protecting trees and natural vegetation.

• Conserving water indoors and out.

• Designing energy efficiency into houses.

• Selecting materials that are durable and recyclable, or created from recycled 

products, and considering the energy that goes into making products.

• Recycling construction materials and reducing on-site waste.

Good places to start on sustainable development are found in the Southface Energy 

Institute’s Sustainable Design, Construction, and Land Development: Guidelines for the 

Southeast (Brown 2000), the NAHB’s Building Greener: Building Better: The Quiet 

Revolution (NAHB 2002c), and the Sustainable Building Council’s Green Building 

Guidelines (SBIC 2003).

G.W. Robinson pipes recycled 

irrigation water to cut water 

use and costs to homeowners at 

the Cobblefield development in 

Gainesville, Florida.
Site Planners

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Sources and Additional Information

• American Forests and the National Associationi of Homebuilders. 1995. 

Building Greener Neighborhoods: Trees as Part of the Plan. NAHB, 

Washington, D.C.

• Brown, W. 2000. Sustainable Design, Construction, and Land 

Development: Guidelines for the Southeast. Southface Energy Institute 

and Oak Ridge National Laboratory, Oak Ridge, Tennessee. 

www.southface.org/home/sfpubs/large-pubs/

Sustainable_community_development.pdf

• Lstiburek, J.W. 2002. Water Management Guide. Energy and Environmental 

Building Association, Minneapolis, Minnesota. www.eeba.org

• McPherson, G.E., D.J. Nowak, and R.A. Rowntree (eds). 1994. Chicago’s 

Urban Forest Ecosystem: Results of the Chicago Urban Forest Climate Project. 

U.S. Department of Agriculture, Forest Service, Northeastern Research 

Station, www.f.fed.us/ne/newtown_square/publications/

technical_reports/pdfs/scanned/gtr186a.pdf

• National Association of Homebuilders. 2002.a Builder’s Guide to the APA’s 

Growing Smart Legislative Guidebook. NAHB, Washington, D.C.

• National Association of Home Builders. 2002b. What 21st Century Home 

Buyers Want: A Survey of Customer Preferences. NAHB, Washington, D.C. 

www.BuilderBooks.com

• National Association of Homebuilders. 2002c. Building Greener: Building 

Better: The Quiet Revolution. NAHB, Washington, D.C.

• Sustainable Buildings Industry Council (SBIC). 2003. Green Building 

Guidelines: Meeting the Demand for Low-Energy, Resource-Efficient Homes. 

U.S. DOE. Washington, D.C. document available at www.SBICouncil.org.

• Sonne, J.K. and R.K. Viera, 2000. “Cool Neighborhoods: The Measurement 

of Small Scale Heat Islands.” Proceedings of the 2000 Summer Study on Energy 

Efficiency in Buildings, American Council for an Energy-Efficient Economy, 

Washington, DC. www.fsec.ucf.edu/bldg/pubs/pf363/index.htm

• Viera, R.K., K.G. Sheinkopf, and J.K. Sonne. 1992. Energy-Efficient Florida 

Home Building, third printing. Florida Solar Energy Center, FSEC-GP-33-88, 

Cocoa Beach, Florida.
Designers

Well-crafted designs capture benefits 

for builders, buyers, and business

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-1

Even good builders can have bad results if they are working toward the wrong product. 

Designers have the job of giving builders the opportunity to do the right thing well.

Building Science and the Systems Approach

Perhaps the most important step in designing any form or function is recognizing 

that the design is for the entire product. No one piece can be changed without 

affecting all related pieces. This simple proposition applies to all systems and allows 

for all kinds of trade-offs. In cars, without any loss in performance, lightweight 

frames may be translated into smaller brakes, a smaller engine, and smaller tires. Or, 

that same change may be used to produce more speed.

In houses, this systems approach recognizes the interaction of windows, attics, 

foundations, mechanical equipment, and all other components and assemblies. 

Changes in one or a few components can dramatically change how other components 

perform. Recognizing and taking advantage of this fact, and applying appropriate 

advances in technology to components, can result in cost and performance payoffs, 

both for the builder and buyer of new homes.

Building America has embraced the systems approach and combined it with 

the technology development and testing that make up building science. As 

with other scientific disciplines, building science provides an intelligent approach to 

understanding complex systems and diagnosing problems. Over time, knowledge, 

tools, and tests are developed that make the science and the product more 

efficient and more powerful. (Adapted from Florida Solar Energy Center Web site 

www.fsec.ucf.edu/bldg/science/basics/index.htm)

QUICK TIPS | DESIGNERS

• Building America brings you the results of research, real-world experience, and 

dialogue with builders from over 25,000 homes nationwide (as of early 2004). 

• System design and building science offer you tools and techniques to 

improve housing performance without sacrificing style and appeal, avoid 

problems plaguing new homes, find cost savings to help your company’s 

bottom line, and give consumers satisfaction in their investment.

• Seek the help of a home energy rating professional or engineer to avoid 

reinventing many of the solutions that have already been found and 

optimize your designs.

• Review the many technologies discussed in this chapter for help in selecting 

the applications right for you.

“If you do the wrong things with good materials and good workmanship, it is still 

wrong. You must do the right thing with good materials and good workmanship.” 

Joseph Lstiburek, Building Science Corporation
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-2

Four steps can help to manage risks and take advantage of system trade-offs.

1) Give builders the right target. Recognize you are designing a complete product—a 

system—and ensure the product is right for the hot and humid climate.

2) Take care of the basics. The basics are proven, cost-effective technologies that 

include good windows, insulation, moisture management, and ventilation. Make sure 

the house has adequate overhangs for shade and rain deflection. Guidelines for many 

of the basics are included later in this chapter.

3) Take only what you need. Size heating and cooling equipment, ducts, and fans to 

match the load. If equipment sizing is normally done by a subcontractor, ensure the 

sub uses the procedures listed in this document to properly size equipment. Proper 

sizing of heating and cooling equipment is a huge opportunity to save money and 

increase profit.

4) Put everything in its place. Be sure there is a place for everything the house requires 

and show it on your plans. Do not leave it to chance where ducts will be placed or 

even where plumbing will run. If there are places that should not be tampered with, 

for example a duct chase, make it clear the space is off limits to plumbers, electricians, 

and others who need to create routes through buildings.

“Understand the theory of your 

construction ....then be sure 

to question your engineer (or 

subcontractor) as to whether 

it’s all really necessary. If 

you don’t get a straight, 

understandable answer, find 

an engineer who will give you 

one. Remember, it doesn’t cost 

the engineer a penny to overdesign. But ultimately someone 

foots the bill.”

Tim Garrison, CEO of ConstructionCalc, made an important point 

about the cost of overdesigning 

structural components. He is 

quoted here because his point is 

equally valid for HVAC and other 

equipment (adapted from Nation’s 

Building News Online, 27 April 

2004, www.nbnnews.com).

Building Science and the Systems Approach: Problem Solving

Moisture, mold, and material degradation are examples of problems that building 

science can help solve. High temperatures create a need for cooling. High humidity 

adds to discomfort and is a source of moisture. Humid air and a cold surface result in 

condensation that can add up to discomfort, material failure, and high repair costs.

Leaky ducts located in attics or crawlspaces create air pressure differences that can draw 

in humid air through cracks and holes and deliver it into the house. Humid air inside a 

cool space encourages the occupant to turn down the thermostat for more cooling. This 

cycle can result in moisture forming as condensation on or in ducts, walls, and other 

assemblies. Accumulated moisture supports mold growth and leads to rotting, warping, 

and staining.

The result is that a small problem in one assembly (leaky ducts) that is inexpensive to 

fix during installation, can lead to big problems in framing, interior finish, and human 

health. Moisture problems may have causes other than leaky ducts, but many unintended 

problems can be avoided in a similar fashion.

Building Science and the Systems Approach: Reaping Rewards

There is more than avoiding problems to encourage you to use a systems approach. For 

example, trade-offs from installing energy-saving measures can help save construction 

costs for heating and cooling equipment. If good windows, adequate insulation, and 

efficient heating and cooling equipment are installed, the heating and cooling equipment 

capacity can also be smaller than typically used and shorter duct runs are possible. All of 

this can add up to reduced costs in heating and cooling equipment that offset the cost of 

the other measures. Using trade-offs to improve economics, durability, and comfort is 

essential to successful business and design.
Designers

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Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-3

The challenge to designers is to carefully select new technologies, consider their cost 

and rewards for your overall system, and use the changes that make sense. Building 

America has taken this systems approach to designing energy-efficient houses. This 

document presents you with information that will give you a straight-forward approach 

to designing houses that qualify for ENERGY STAR. Design information is provided 

for a variety of measures and components in the remainder of this section. Put in the 

recommended measures and your houses should qualify. You may also qualify using 

other trade-offs. Suggestions from Building America’s experience are also included that 

will improve the health and comfort of your homes. 

The Cost of Doing Business

The cost of building homes is different for every builder. Technique, experience, 

subcontractors, suppliers, and the size of purchases can all make a difference in how 

much a home costs to build. Even a builder’s accounting methods can influence 

how costs are reported. These variables all apply to energy-efficiency measures and 

contribute to the difficulty of providing cost estimates that apply to more than a 

limited example over a short period of time.

In addition to variability, other considerations apply to costs. First, the cost of higher 

quality housing represents an added value and holds the potential of a higher profit. 

Second, a tremendous benefit of the systems approach described above is that the costs 

of energy-efficient measures can often be offset by savings in other areas. And finally, 

buyers can recover any additional costs through reduced utility bills, increased resale 

value, and for some, better mortgage terms.

FIGURE 1: Cost Comparison of Energy Efficient Measures to Conventional Practice

Source: Edminster, Pettit, Ueno, Menegus, and Baczek 2000.

Some builders say that meeting 

ENERGY STAR qualifications 

does not increase their costs. 

However, they must focus on 

higher quality installations. 

Other builders suggest additional costs up to $1,500 to 

the consumer, but it’s unclear 

if these values apply beyond their 

experience. The chart at left 

shows an estimate of costs made 

in the year 2000 for homes built 

in the hot and humid climate 

using a design with calculated 

savings of 50% for heating and 

30% for cooling. The example is 

intended to show how costs and 

savings trade off, rather than 

to provide estimates of 

dollar savings.

Unvented Roof

Advanced Framing

-$100 SAVINGS

-$250 SAVINGS

COST COMPARISON TO CONVENTIONAL MEASURES

Less Cost Conventional More Cost

+$700 ADDED COST

+$150 ADDED COST

Controlled Ventilation System

+$250 ADDED COST

Dehumidifier

+$300 ADDED COST

+$300 ADDED COST

• No need to install vents

• 2x6s @ 24" o.c. instead of 2x4s @ 16" o.c.

Right-Sized Air Conditioner System

-$750 SAVINGS • 2-ton reduction

• Moving insulation

High-Performance Windows

COST DIFFERENCE
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-4

Best Practice: Building America recommends working with a HERS rating professional, 

architect, or engineer early in the design process to help select and size materials and 

equipment. The building scientists can be especially helpful in right sizing heating and 

cooling equipment. By forming a relationship with a rater who later will inspect the 

construction site, designers can get valuable feedback about what works and what house 

features require more detailed information for the site supervisor and the trades.

HERS Ratings and Qualifying for ENERGY STAR

The best use of a HERS rater involves working with your rater in creating your design. 

When following this path, the rater analyses your construction plans, in addition to 

at least one on-site inspection and test of the home. The plan review allows the home 

energy rater to view technical information such as orientation (if known), shading area, 

proposed equipment ratings, and insulation levels. The on-site test involves blower 

door and duct testing. Results of these tests, along with inputs derived from the plan 

review, are entered into a computer simulation program to generate the HERS score 

and the home’s estimated annual energy costs, based on heating, cooling, and hot 

water heating requirements.

A HERS rating is an evaluation of the energy efficiency of a home, compared to a 

computer-simulated reference house (of the identical size and shape as the rated home) 

that meets minimum requirements of the Model Energy Code (MEC). The HERS 

rating results in a score between 0 and 100, with the reference home assigned a score 

of 80. From the 80-point level, each 1 point increase in the HERS score results in a 5 

percent reduction in heating, cooling, and hot water energy usage (compared to the 

reference house). An ENERGY STAR qualified new home, which is required to be 

30% more efficient, must attain a HERS score of at least 86.

Your HERS rater can be a tremendous resource in the design phase. Raters who are 

trained in building science may help to solve construction problems. One important 

job your rater can help with is to work with the mechanical contractor to correctly 

size heating/cooling equipment, perform room-by-room calculations to determine the 

supply air needed for each room, and work with the mechanical contractor on duct 

sizes and lay out. This is likely to eliminate callbacks due to comfort complaints and 

can save substantial money by right-sizing the heating and cooling equipment. During 

the design stage, the rater can suggest alternatives to attain desired performance levels in 

the areas of energy, comfort, durability, and health.

Selecting a HERS rater is much like selecting any other professional services provider, 

such as an architect, accountant, or engineer. Be sure you are comfortable with the 

rater’s communication skills, experience, training, and references before making a 

selection. 

Best Practice: Building America recommends that every house receive a site inspection 

and diagnostic tests from a HERS rating professional. The information gained from 

these tests can help to isolate specific problem areas that can be solved with further 

training, more explicit details, better building materials, or other production changes.

HERS RATER

Building America recommends working 

with a HERS rater or building scientist 

early in the design process.

SITE INSPECTION

Building America recommends that 

every house receive site inspections 

and diagnostic tests.
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-5

Heat and Humidity

The recommendations in this Best Practices guide apply to the entire hot and humid 

climate region. If you aren’t sure that your project is within the hot and humid climate 

region we suggest working with a HERS rater to confirm your zone. Or you can visit 

the Building America Web site and view the “Building America Climate Zones by 

Counties of the United States” document.

Hot and humid climates face several challenges for home building. The intense solar 

radiation in such climates imposes a large thermal load on houses that can increase 

cooling costs, affect comfort, and damage home furnishings. This chapter contains 

some of the best methods to minimize the impact of solar radiation on the building, its 

mechanical system, and its occupants.

Moisture is a significant problem in this climate in the form of both high humidity and 

high rainfall. Most of the hot and humid climate receives more than 40 inches of annual 

precipitation. Some areas get more than 60 inches of annual precipitation. The ambient 

air has significant levels of moisture most of the year. Since air conditioning is installed 

in most new homes, cold surfaces are present where condensation can occur. Controlling 

the infiltration of this moisture-laden air into the building envelope and keeping moisture 

away from cold surfaces are major goals of design and construction in this climate zone.

Hot and Humid Climate Design Best Practices

Housing types vary greatly throughout all of the different climate zones, but nowhere 

is the contrast so great as in the hot-humid climate of the southern United States. In 

many parts of Florida, block wall assemblies predominate, whereas wood frame is most 

commonly used in Texas.

In the face of this diversity, this document does not recommend a single set of measures 

for achieving the 30% energy savings in space conditioning, water heating, and 

reaching ENERGY STAR qualification. We do recommend following the principles 

included in these Best Practices and adjusting these practices and your designs to make 

them work together. We also recommend working with a building scientist such as a 

Home Energy Rating Professional to help with the transition.

The best practices described in this manual are intended to give builders and designers 

recommendations resulting from Building America’s work on over 25,000 homes. 

Building scientists have tried and tested these measures on actual homes in the field. 

This does not mean that every measure will be for you. However, as builders start 

aiming for higher performing homes, details become more important. It may not make 

sense to install the best practice in every instance. Sometimes you can get away with 

less. But making this decision should involve an evaluation of the risks of not using the 

best practice, and questioning how the overall house system may be impacted. 

Site – Drainage, Pest Control, and Landscaping

Additional planning information related to overall site development is presented in the 

Site Planners chapter.

Drainage

Moving moisture away from a building is critically important to maintaining structural integrity.

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

FIGURE 2:

Hot and Humid Climate Zone

Drain Wall

Drain Roof

Drain Building

Drain Site

Drain Ground Drain Ground

Drain Site

Drain Materials

Drain Components

Drain Openings

FIGURE 3: Drainage

Adapted from Lstiburek 2003
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-6

Best Practice: Grading and landscaping should be planned for movement of building 

run-off away from the home and its foundation, with roof drainage directed at least 3 

feet beyond the building, and a surface grade of at least 5% maintained for at least 10 

feet around and away from the entire structure. This topic is also discussed in the Site 

Planners chapter.

Pest Control

Termites are a serious menace in the hot and humid climate.

Best Practice: Based on local code and Termite Infestation Probability (TIP) maps, 

use environmentally appropriate termite treatments, bait systems, and treated 

building materials for assemblies that are near soil or have ground contact (see 

www.uky.edu/Agriculture/Entomology/entfacts.htm). 

Landscaping 

Landscaping is a critical element to the marketability of a house. But plants must be 

placed to avoid interfering with visual inspections of termite access. Planting can also 

be used to shade foundations and reduce cooling loads.

Best Practice: Plantings should be held back as much as 3 feet and no less than 

18 inches from the finished structure, with any supporting irrigation directed away 

from the finished structure. Plantings may be selected to shade the foundation edge, 

especially on the southwest corner of the structure. Choosing drought-tolerant 

plantings results in less irrigation and less chance for irrigation water to create a 

moisture problem in the house. Decorative ground cover—mulch or pea stone, for 

example—should be thinned to no more than 2 inches for the first 18 inches from the 

finished structure. More landscaping information can be found on DOE’s Web site at 

www.eere.energy.gov/consumerinfo/factsheets/landscape.html.

Foundation Measures 

Slabs are more cost effective and prevalent in new construction in the hot and humid 

climate zone than other foundation systems. Building foundations should be designed 

and constructed to prevent the entry of moisture and other soil gases. Moisture may 

cause structural decay and can contribute to human health and comfort problems. 

Radon that enters a home is breathed by occupants and may cause lung cancer. 

Best Practice: Slabs require a 6-ml polyethylene sheeting directly beneath the concrete 

that accomplishes vapor control and capillary control for the slab. The vapor retarder 

should continuously wrap the slab as well as the grade beam. Other solutions may work 

for thegrade beam, but a moisture retarder is needed to damp-proof the stem wall.

Best Practice: A sand layer under the slab should never be placed between a vapor 

retarder and a concrete slab. Cast the concrete directly on top of the vapor barrier. 

Differential drying and cracking is better handled with a low water-to-concrete ratio 

and wetted burlap covering during initial curing. 

Best Practice: Sub-slab drainage should consist of a gravel capillary break directly 

beneath the slab vapor retarder.

In addition to other benefits, the gravel and vapor barrier are important first steps to 

radon control. The gravel provides a path for radon and other soil gas to escape to the 

TERMITES

Use environmentally appropriate 

termite treatments.

PLANTINGS

Select draught-tolerant plantings 

and keep them at least 18 inches 

from the foundation.

VAPOR CONTROL

Achieve vapor and capillary control 

with 6 mil polyethylene sheeting 

directly below the slab.

CASTING CONCRETE

Cast the concrete directly on top of the 

vapor barrier, with no sand in between

DRAINAGE

Place a gravel capillary break directly 

beneath the slab vapor barrier.

GRADING

Plan grading and landscaping to direct 

run-off away from the home and its 

foundation.
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-7

atmosphere rather than being drawn into the house. And the vapor retarder helps to 

block soil gas entry into the house. Where gravel is scarce, such as in Florida, builders 

often pour slabs onto sand. When sand or other native fill is used, a 3- or 4-inch 

perforated and corrugated pipe loop can be use for both drainage and radon control. 

Or drainage matting may be installed over sand. Both approaches are described in a 

US EPA document described in the following list., Building Radon Out (2001).

Radon-resistant construction practices are described in the following documents:

• ASTM WK2469 New Standard (Formerly E1465-92)(draft) Guide for 

Radon Control Options for the Design and Construction of New Low-Rise 

Residential Buildings

• Model Standards and Techniques for Control of Radon in 

New Residential Buildings (U.S. EPA 1994)

• Building Radon Out: A Step-by-Step Guide on How to Build 

Radon-Resistant Homes (U.S. EPA 2001) available on the web at 

www.epa.gov/199/radon/images/buildradonout.pdf.

FIGURE 4: Typical Building Slab Foundation

Adapted from Building Science Corporation

NOTE: Rigid slab insulation is typically 

not economical in hot and humid climates.

CONCRETE SLAB

SEAL ALL SLAB

PENETRATIONS

MASONRY WOOD FRAMED

GRAVEL BASE

����������������������������

PERFORATED

DRAIN PIPE

6 MIL. POLYETHELYLENE

VAPOR DIFFUSION

RETARDER

��������������������������

FOAM INSULATION

�������������������������������������

��������������������������������

RADON REDUCTION

 3" PLASTIC PIPE VENT STACK

OPTIONAL BLOWER

SILL GASKET

MEMBRANE

��������������������������������

METAL TERMITE 

FLASHING

ROOF FLASHING
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-8

Best Practice: Other than identifying areas that have had radon problems, it is not 

possible to predict radon levels in houses prior to construction, so it is important to 

include inexpensive radon control measures. One measure recommended by the EPA 

to control potentially high radon levels and other soil gasses, is a passive soil gas stack 

connected to a perforated drain pipe embedded in the gravel under the slab. The stack 

may also be attached to a perforated pipe loop or mat. If it turns out the house has 

unacceptable radon levels, a fan can be added to the stack to actively draw soil gas away 

from the house. To determine potential radon levels in the county in which you are 

building, visit the EPA’s radon potential map at: www.epa.gov/radon/zonemap.html.

For information about local variation in radon levels you can find local contacts 

at the following EPA web site: www.epa.gov/iaq/whereyoulive.html. The EPA 

divides counties into one of three zones based on radon level potential. The EPA 

recommends that all homes built in Zone 1 (high radon potential) areas have 

radon reduction systems.

Foundation Energy Performance 

Slabs in this climate are generally not insulated, even at the perimeter, because 

of the low overall heating load and code restrictions on below-grade use of rigid 

foam insulation.

Crawlspace Foundation Systems

Although not prevalent, some houses in the hot and humid climate are built with crawl 

spaces. Crawlspaces should be built as a conditioned space. Insulation should be applied 

to exterior walls and vents to the exterior should not be installed. The crawlspace 

should receive conditioned air from at least one supply duct, and transfer grills should 

allow for the transfer of air back to the living space. Other features include ground 

cover that is continuous and sealed to the perimeter walls and piers, air sealing of the 

exterior walls, and sealed air distribution ducts. If a heating system is installed in the 

crawlspace, use only a sealed combustion appliance. For more information see:

• The addendum to the Site Supervisors chapter, look for the section 

entitled: Details for Mechanically Vented Crawlspaces. 

• Yost, Nathan. May 2003. “The Case for Conditioned, Unvented Crawl 

Spaces.” Building Safety Journal. Available on the BSC web site at: 

www.buildingscience.com/resources/articles/24-27_Yost_for_author.pdf

• The Montgomery Building Profile in the Building America: Houses that Work

section of the BSC Web site: 

www.buildingscience.com/housesthatwork/hothumid/montgomery.htm

Structural Moisture Control

Best Practice: Roof and wall assemblies must contain surfaces that will drain water in a 

continuous manner over the entire area of the building. Water must have a path that 

will take it from its point of impact, around any elements such as windows, doors, and 

seams, all the way to the exterior ground, sloping away from the house.

Best Practice: In areas with potentially high winds and heavy rains install four inch to 

six inch “peal and seal” self adhering water-proofing strips over joints in roof decking 

before installing the roof underlayment and cover.

VAPOR BARRIERS

Roof and wall assemblies must 

contain elements that, individually 

and in combination, permit drying 

of spaces inside of walls.

RADON

Houses built in areas with potentially 

high radon levels can install a soil 

gas stack to draw soil gas away 

from the home.

WATER-PROOFING ROOF DECKING

Install water-proofing strips over 

joints in roof decking.
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-9

Two types of rain management systems have been identified: barriers and screens. 

Barriers rely on exterior cladding to drain water and are best used with water-resistant 

building materials, such as masonry block or concrete. Screens have multiple lines of 

defense against water entry and are used with wood, brick, and gypsum-based materials. 

Both barriers and screens rely on lapped flashings to direct water to the exterior at 

critical areas such as seams, windows, and penetrations. In both systems, it is essential 

that materials are lapped shingle fashion to direct water down and out, away from the 

wall assembly.

Water Leakage

One critical point of concern is water leakage around windows. The EEBA Water 

Management Guide offers examples of many window flashing applications. The window 

flashing examples here are taken from the Trades chapter. These examples are for 

homes with housewrap and plywood or OSB sheathing.

Best Practice: Specify that flashing be installed for all windows and doors. 

Window and door flashing details should be designed to match specific wall 

assemblies and claddings.

Flashing systems should be designed in accordance with the ASTM standard entitled 

Standard Practice for Installation of Exterior Windows, Doors, and Skylights (ASTM 

2002). In addition to the standard and the EEBA guide, see DOE’s Technology 

Fact Sheet on Weather-Resistive Barriers (DOE 2000), available on the web at 

www.eere.energy.gov/buildings/documents/pdfs/28600.pdf. 

The hot and humid climate is especially vulnerable to catastrophic high-wind, heavyrain events, such as hurricanes, tropical storms, and tornadoes. Proper structural 

fastening and impact resistant windows, doors, and skylights are critical to surviving 

high winds. Proper use of roofing materials can help roofs withstand high winds and 

protect against severe rains. This document does not provide detailed information on 

disaster survival but the following sources provide structural details and guidance and a 

listing of building materials acceptable for high wind areas.

• Federal Emergency Management Agency. Building a Safe Room Inside Your 

Home. www.fema.gov

• Florida Alliance for Safe Homes – FLASH, Inc. Building guidelines for 

hazardous areas in Florida. Blueprint for Safety. www.blueprintforsafety.org

• Institute for Business and Home Safety. The IBHS has building guidelines and 

public information. www.ibhs.org

• Miami-Dade County Building Code Compliance Office. This site includes a 

searchable database of building materials approved for high-wind locations. 

www.buildingcodeonline.com

• U.S. Department of Energy. A training program for home inspectors to 

identify hazards. www.eere.energy.gov/weatherization/hazard_workshop.html

Vapor Management Around Windows

With most areas in the hot and humid climate receiving at least 40 inches of rain per 

year, the source of water problems should be obvious, the rain. But water has many 

guises and water in its liquid state is not the only problem. Water can also cause 

WINDOW FLASHING

Flashing should be installed 

for all windows.

FIGURE 5:

Window Flashing Building Tips

Complete instructions for window 

flashing are provided in the Trades 

and Crafts section of this handbook.

CAULK

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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IMPERMEABLE COVERINGS

Never install impermeable 

coverings inside the house.

BACKPRIMING

Backprime all wood cladding 

to avoid water saturation.

AIR SPACE

Creating an air space between 

the exterior finish and the drainage 

plane effectively increases the 

durability of both components.

TWO LAYERS OF 

BUILDING PAPER OR FELT

Consider installing two layers 

of building paper or felt to create a 

double drainage plane.

CAREFUL INSTALLATION

Pay close attention to lapping 

around windows and doors, as 

well as the proper use of fasteners.

problems as vapor. The problem is especially bad when vapor gets trapped within 

an assembly, such as a wall; turns to its liquid form (condenses); and wets structural 

assemblies. Condensation can also form in and on ductwork, especially when air 

conditioning cools duct surfaces that come in contact with humid air, such as in an 

attic or crawlspace. The recommendations below are intended to control both liquid 

water and vapor.

Best Practice: Do not install impermeable coverings, such as vinyl wallpaper, on exterior 

walls and do not install vapor barriers on the framing side of gypsum board or other 

wall coverings. Use unfaced insulation.

Best Practice: Water soaking through wood can carry with it contaminants that interfere 

with the ability of housewraps and building papers and felts to resist water. One step in 

the solution is to backprime all wood cladding to avoid water saturation and migration. 

This practice also makes the wood much more durable. 

Best Practice: Creating an air space between the cladding and the drainage plane 

effectively increases the durability of both components. With some exterior 

finishes, such as bricks, an air space is even more important. An air space stops 

the capillary movement of moisture, stops the contamination of the drainage 

plane via contact with the cladding, and allows for better drying. Information on 

housewrap and building paper performance behind brick and stucco can be found at 

www.buildingscience.com/resources/walls/brick_stucco_housewraps.pdf

Best Practice: If building paper or felt is used in areas prone to severe rain, install two 

layers. The use of two layers was once common and provides better than twice the 

performance of one layer. By providing a double drainage plane, they offer increased 

resistance to leakage at fasteners and allow for more flexible installation. 

Best Practice: Installation is key for all types of housewraps. The sheets must be lapped, 

shingle-style, especially over and around windows, doors, and other penetrations (and 

their flashing systems). Use manufacturer-specified fasteners and space them closely 

enough to provide required support.

Additional information on moisture control can be obtained from:

• DOE’s Technology Fact Sheet on Weather-Resistive Barriers, available on 

the web at www.eere.energy.gov/buildings/documents/pdfs/28600.pdf

• Building Science Consortium’s web site at: www.buildingscience.com/

housesthatwork/buildingmaterials where you can compare wraps and 

other materials 

• www.buildingscience.com/resources/walls/problems_with_housewraps.htm 

• The following article provides an overview of house wraps and was a key 

source for this section: Straube, John. 2001. “Wrapping it Up,“ Canadian 

Architect. May, 2001. Available at: www.cdnarchitect.com.
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • DES-11

Roof and wall assemblies must contain elements that, individually and in combination, 

permit drying of spaces inside of walls and other assemblies. Exterior housewraps, 

including building paper, will allow vapor to pass through and should be installed on 

the exterior of sheathing. Interior walls should be painted but not covered with plastic 

vapor retarders (on the framing side of gypsum board) or impervious coatings, such as 

vinyl wallpaper. 

A more recent and graphical reference on moisture control is the EEBA Water 

Management Guide (Lstiburek 2003), available for sale from the EEBA Bookstore, on 

the web at: www.eeba.org/bookstore.

Housewrap, Building Paper, or Felt – Your Choices for Wrapping it Up

Housewrap, building paper, or impregnated felt should be part of the exterior wall system 

that protects the building from water penetration. None of the materials are waterproof, 

but are intended to shed rainwater that penetrates exterior cladding. The surface formed 

by these materials is called a drainage plane, house membrane, or rain barrier. They are 

used to shed liquid water that may penetrate siding or roofing and to prevent liquid water 

from wicking through them, while remaining sufficiently vapor permeable (“breathable”) 

for outward drying (Straube 2001). By helping to keep building materials dry, these 

membranes improve building durability, decrease maintenance costs, and reduce the risk 

of moisture-related problems such as pests, mold, and rot. 

Building Paper is a Kraft paper sheet impregnated with asphalt to increase its strength 

and resistance to water penetration. It is primarily employed as a drainage layer. It is 

graded according to a test of the amount of time required for a water-sensitive chemical to 

change color when a boat-shaped sample is floated on water. Common grades include 10, 

20, 30, and 60 minutes. The larger the number, the more resistant the paper is to water. 

Building Felts have been in use over a hundred years. Originally made from rags, today’s 

felts are made of recycled paper products and sawdust. The base felt is impregnated with 

asphalt. Ratings for felt harken back to the traditional weight of the material before the oil 

crisis of the 1970s. At that time 100 square feet of the material (1 square) weighed about 

15 pounds. Modern #15 felt can weigh from 7.5 to 12.5 pounds per square depending on 

the manufacturer. 

Housewrap typically refers to plastic sheet materials. Housewrap comes in a variety of 

materials and can be perforated or non-perforated. If joints and connections are sealed, 

housewraps can serve as air retarders to reduce air leakage. Housewraps are highly resistant 

to tearing, unlike building paper. Non-perforated wraps tend to have higher liquid water 

resistance because the holes between plastic fibers are very small. 

Most building paper is UV-resistant, whereas recommended housewrap exposure limits 

may vary by manufacturer. Check with manufacturers if outdoor exposure will exceed 

a month. One person can usually install building paper, while housewrap requires two 

people. However, housewrap is available in wide sheets that can cover an entire one-story 

wall surface in a single pass.
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Structural Air Sealing

FIGURE 6: Envelope Air Sealing

Best Practice: Use either interior gypsum board, exterior sheathing, or both as an air 

flow retarder. Exterior stucco may also serve as an air barrier. Carefully seal big and 

little holes. Pay particular attention to sealing shared walls and attic spaces between 

garages and houses.

A tight building envelope is necessary to control the movement of air in and out of 

building assemblies. Air infiltration can contribute to problems with moisture, noise, 

dust, and the entry of pollutants, insects, and rodents. Using mechanical ventilation as 

a superior approach to supplying fresh air is discussed in the section on Mechanicals, 

Electrical, and Plumbing.

Moisture-laden air moving into wall or roof assemblies (particularly from the 

outside while cooling in hot-humid climates) may lead to condensation and result in 

deterioration of moisture sensitive materials. Airflow retarders can be installed on the 

interior or the exterior side of the envelope or on both sides. Insulation made up of batt 

or loose fill products does not seal against air leakage. Rigid foam board insulation can 

be used as both a moisture and air retarder.

Controlling air movement through the building envelope requires sealing both the 

“big” holes and the “little” holes. The big holes occur behind bathtubs and showers 

on exterior walls, behind fireplaces, and where soffits or utility walls (double wall with 

chase) meet exterior walls or ceilings. Recessed lights collectively can be a really big hole 

AIR SEALING

Be sure to seal shared walls and 

attic spaces between garages 

and houses.

Building Science Corporation
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in the ceiling assembly. These big holes are responsible for wasted energy (high utility 

bills) and condensation that can cause mold and wood decay. These holes are easy to 

seal during the framing stage but only when someone has the responsibility for making 

sure it gets done. Only airtight recessed lights (ICAT rated) should be used in ceilings 

leading to unconditioned spaces.

The little holes occur between framing members (such as band joist to sill plate), 

around electrical boxes, and where plumbing or wiring penetrate the envelope. All 

penetrations leading to unconditioned spaces should be sealed with foam or caulk. See 

the Trades chapter, Building Tips on air sealants and the instructions for plumbers, 

electricians, and framers. Also see the sections later in this chapter for plumbing 

and electrical. 

When air sealing drywall, gypsum board acts as an interior air flow retarder. The 

gypsum board is sealed to the framing members at the perimeter of exterior walls and 

around penetrations such as doors, windows, and attic hatches. The gypsum board is 

also sealed to electrical boxes on exterior walls. Air cannot move through the gypsum 

board and the taped corners.

There are many approaches and practices to sealing buildings. Many details and 

photographs of air sealing techniques can be found on the Building Science 

Corporation web site at: www.buildingscience.com/housesthatwork/airsealing.htm, 

in the EEBA Builders Guides, and in the DOE Technology Fact Sheet on Air Sealing

available on the web at: www.eere.energy.gov/buildings/documents/pdfs/26448.pdf.

Best Practice: One area to pay attention to for sealing is the intersection of the walls and 

roof. This area may involve an attic, cathedral ceiling, knee walls, all of the above, or 

other examples of complex rooflines. Figures 7 and 8 show knee wall examples. Tight 

sealing of this intersection may require blown-in foam.

Another area needing special attention for occupant health and safety is sealing shared 

walls and ceilings between attached garages and living spaces. Carefully seal any 

penetrations, block air pathways through the attic, and weatherstrip any doors.

Structural Thermal Performance

Properly installed insulation is like your favorite winter comforter for keeping 

heat where it’s wanted. Any interior insulation type is acceptable that has vapor 

permeability. These include cellulose, fiberglass, and foam. Foam can also serve as an 

air retarder, but air sealing must be accomplished by a separate component or system 

when cellulose or fiberglass is used.

The following descriptions of insulation were adapted from DOE’s Fact Sheet on 

Insulation available on the web at: www.ornl.gov/sci/roofs+walls/insulation/ins_08.html.

FIGURE 7 & 8: Knee Walls

Figures 7 and 8 show possible 

approaches to sealing knee walls. 

Seal knee wall to create a 

continuous air barrier. Knee walls 

can be sealed following the wall 

and attic floor.

In new homes, it is preferred 

to seal along the sloping edge 

of the attic roof. 

Hardboard

Seal

Seal

Use rigid foam or sheet goods

to seal joist cavities

Desired

ventilation

INTERSECTIONS OF WALLS & ROOF

Tight sealing of the intersection 

of the roof and wall may require 

blown-in foam.
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BLANKETS

Blankets in the form of batts or rolls are flexible products made from mineral fibers, 

typically fiberglass. They are available in widths suited to standard wall, floor, and 

attic framing spaces. Continuous rolls can be hand-cut and trimmed to fit. They are 

available with or without vapor retarder facings. High-density fiberglass batts are 

about 15% more effective than traditional batts. Even if you choose to use other types 

of insulation, such as blown or sprayed in cellulose or foam, batts can be installed in 

areas that may become inaccessible as construction unfolds. These areas could include 

behind-shower inserts, stairs, or rim joists. Batts also make good dams in attics around 

access points or other areas where blown-in insulation should be held back. 

Best Practice: When fiberglass batt insulation is specified, use high-density, unfaced 

batts. Batt facing is a vapor retarder and can trap moisture inside walls.

BLOWN-IN

Blown-in, loose-fill insulation includes loose fibers or fiber pellets that are blown into 

building cavities or attics using special pneumatic equipment. Another form includes 

fibers that are co-sprayed with moisture or an adhesive that allows them to set in 

walls and makes them resistant to settling. The blown-in material can provide some 

resistance to air infiltration if the insulation is sufficiently dense.

FOAMED-IN-PLACE

Foamed-in-place polyurethane foam insulation can be applied by a professional 

applicator using special equipment to meter, mix, and spray into cavities. Polyurethane 

foam makes an excellent air seal and can be used to reach hard-to-get-at places.

RIGID INSULATION

Rigid insulation is made from fibrous materials or plastic foams that is pressed or 

extruded into sheets and molded pipe-coverings. These provide thermal and acoustical 

insulation, strength with low weight, and coverage with few heat loss paths. Such 

boards may be faced with a reflective foil that reduces heat flow when next to an air 

space. Foil facing also makes the board nearly impervious to water and vapor and so 

should be used with caution. Rigid foam insulation may be used in combination with 

other insulation types, such as on the exterior of walls that are filled with cellulose or 

fiberglass. Foam sheets that may be in contact with the ground should be borate-treated 

for termite resistance. (See Figure 10 on page 16 for an example of rigid foam insulation) 

REFLECTIVE INSULATION SYSTEMS

Reflective insulation systems are fabricated from aluminum foils with a variety of 

backings such as roof sheathing, kraft paper, plastic film, polyethylene bubbles, or 

cardboard. The resistance to heat flow depends on the heat flow direction; this type 

of insulation is most effective in reducing downward heat flow and requires an air 

space adjacent to the reflective surface. Reflective systems are typically located between 

roof rafters, floor joists, or wall studs. Reflective insulation placed in walls must be 

perforated. If a single reflective surface is used alone and faces an open space, such as 

an attic, it is called a radiant barrier. Radiant barriers are sometimes used in buildings 

to reduce summer heat gain and winter heat loss. They can be effective in the hot 

and humid climate at reducing peak cooling loads, especially if ductwork or cooling 

INSULATION

Use high-density batts, when 

fiberglass batt insulation 

is specified.

Blown-in wall insulation

Batt insulation

FIGURE 9: Insulation

Reflective insulation

Soy-based foams are now available

(Photo: Building Science Corporation)
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equipment is located in the attic. All radiant barriers must have a low emittance (0.1 or 

less) and high reflectance (0.9 or more). Additional information on radiant barriers is 

available in the following sources:

• FPC Residential Monitoring Project: New Technology Development 

– Radiant Barrier Pilot Project, available at the FSEC Web site at: 

www.fsec.ucf.edu/bldg/pubs/rbs/index.htm.

• DOE’s Radiant Barrier Attic Fact Sheet, available on the web at 

www.ornl.gov/sci/roofs+walls/radiant/rb_01.html

Frame Walls 

Best Practice: Best practice for frame wall construction involves advanced 

framing techniques. However, these techniques are not required to achieve 

30% space conditioning energy savings in the hot and humid climate. If you 

want to gain greater efficiency, more information on advanced framing can be 

found in the guidance provided in this document for code officials, in the EEBA 

Builders Guides, in DOE’s Fact Sheet on Wall Insulation, and on the web at 

www.buildingscience.com/housesthatwork/advancedframing/default.htm. If advanced 

framing is to be used, a detailed plan should be developed showing framing placement.

External walls with 2 x 4 framing may achieve 30% energy space conditioning savings 

in the hot and humid climate and should include the following features:

• Examples of exterior finish can include stucco over paper (paper to have perm 

rating of <1 perm) backed with lath, vinyl siding, or cementitous board.

How Much Insulation Do You Need?

This is an excellent question to ask your Home Energy Rater. The answer depends 

on your location, the overall design, and the efficiency of other building features. 

The ENERGY STAR website contains Builder Option Packages (BOPS) that 

recommend insulation levels on a county by county basis. The BOPS can be found at 

www.energystar.gov. Examining the ENERGY STAR BOPs provides some examples 

of how insulation can be traded off with other features such as efficient windows and 

HVAC systems. DOE can also help with insulation recommendations for each zip code. 

Visit the web site below. Have in hand the first three digits of your zip code and the 

type of heating system that you are considering. The calculator will recommend an 

insulation level.

www.ornl.gov/sci/roofs+walls/insulation/ins_16.html

If you prefer to work with a map, the following DOE Web site will give you 

recommended insulation levels.

www.eere.energy.gov/consumerinfo/energy_savers/r-value_map.html

These recommendations are only guidelines and are limited in scope. The more complex 

or advanced your design, the more you should rely on specific calculations.

ADVANCED FRAMING

Consider advanced framing 

techniques when contructing walls.
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• A housewrap should be installed as an air and water barrier.

• Insulation may be R-13 (high-density) friction-fit, unfaced fiberglass 

insulation or blown-in cellulose insulation.

• Frame walls between the garage and the conditioned space, including bonus 

rooms, should have R-13 friction-fit, unfaced batt insulation.

• Rim joists: unfaced R-13 friction-fit batt insulation cut to fit.

• Penetrations: Foam seal or caulk all top-plate penetrations and 

exterior wall penetrations.

• In addition to sealing all penetrations, air leakage through the walls should be 

controlled by sealing the gypsum board. Pay particular attention to air sealing 

penetrations to garages and porches.

Masonry Walls 

Masonry walls are common in parts of the hot and humid environment, especially 

south Florida. Masonry walls may be finished with stucco, wood, or other claddings. 

Best practices to improve thermal efficiency include the following:

• Semi-vapor permeable rigid insulation should be installed on the interior of 

wall assemblies and should be unfaced. Foil facing and polypropylene skins 

should be avoided.

• Wood furring should be installed over rigid insulation. The rigid insulation 

should be continuous over the surface of the wall, except for a 2x4 furring at 

the intersection with the ceiling. This blocking attaches directly to the masonry 

block and serves as draft and fire stop. The rigid insulation abuts the blocking 

but does not cover it or extend behind it. Penetrations: Foam seal or caulk all 

top plate penetrations and exterior wall penetrations.

• Electrical boxes can be surface mounted to the masonry, avoiding chipping 

or chiseling. The rigid insulation, furring, and gypsum board will build up 

around the box for a flush finish.

• Use pressure treated lumber to frame out sub-jambs and spacers within 

window and door rough openings.

• As with other walls, penetrations to the exterior or through top and bottom 

plates should be foam sealed or caulked.

• In addition to sealing all penetrations, air leakage through the walls should be 

controlled by sealing the gypsum board. Pay particular attention to air sealing 

penetrations to garages and porches.

• When pouring the slab take care to create a seat in the concrete to accept the 

block and seats in the concrete to act as drain pans where exterior doors and 

sliding doors will be located. 

More information on masonry construction can be found in the Builders Guides

(Lstiburek 2002) and on the web at the Building America Houses that Work section of 

the Building Science Corporation Web site www.buildingscience.com/

housesthatwork/hothumid/orlando.htm. Look for the Orlando Profile. Window 

flashing details can be found in the ASTM standard entitled Standard Practice for 

FIGURE10: Masonry Walls
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Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Installation of Exterior Windows, Doors, and Skylights (ASTM 2002) and the EEBA 

Water Management Guide. The Water Management Guide also contains information on 

other approaches to draining masonry assemblies. The Trades chapter contains a 

building tips sheet for masonry walls.

Concrete Walls

Some builders in the hot and humid climate are beginning to use poured concrete walls 

for residential construction. For more information on this approach see Builder System 

Performance Package Targeting 30%-40% Savings in Space Conditioning Energy Use

prepared by CARB (CARB 2004).

Windows

Best Practice: Specify efficient windows to control solar energy gains and to help reduce 

heating and cooling loads. Some Building America experts recommend that, nationwide, 

windows be used with a U-factor of 0.35 or lower and a SHGC of 0.35 or less. Note 

that ENERGY STAR qualification can be met with windows at less stringent ratings.

Windows are a prominent feature of any wall. High-performance windows can be an 

easy way to achieve ENERGY STAR qualification. Efficient windows will add expense 

to your project, but will provide tremendous value in comfort, durability, and energy 

savings. High-performance windows add so much to energy efficiency that smaller 

cooling and heating equipment can often be specified, which may recapture much of 

the cost. A voluntary rating system developed by the National Fenestration Rating 

Council (NFRC) provides performance information for about half the windows 

sold. The NFRC label contains ratings for the following features. You can find more 

information about the NFRC on the web at: www.nfrc.org.

• U-factors take into account the entire window assembly and rate how well 

the window prevents heat from passing through the window. The lower the 

U-factor the better the window performs at stopping heat flow. U-factors are 

the inverse of R-values used to measure the effectiveness of insulation. U-factor 

values for windows generally fall between 0.20 and 1.2.

• SHGC is the solar heat gain coefficient, which measures how well the window 

blocks heat caused by sunlight. The lower the SHGC rating the less solar heat 

the window transmits. This rating is expressed as a fraction between 0 and 1.

• Visible transmittance (VT) measures how much light comes through a 

window. VT is expressed as a number between 0 and 1. The bigger the 

number the more clear the glass.

• Air leakage through a window assembly is included on most manufacturers’ 

labels, but is not required. The AL rating is expressed as the equivalent cubic 

feet of air passing through a square foot of window area (cfm/sq.ft.) The lower 

the AL, the less the window leaks. A typical rating is 0.2.

• Another optional rating is Condensation Resistance (CR), which measures 

the ability of a product to resist the formation of condensation on the interior 

surface of that product. The higher the CR rating, the better that product 

is at resisting condensation formation. While this rating cannot predict 

condensation, it can provide a credible method of comparing the potential 

of various products for condensation formation. CR is expressed as a number 

between 1 and 100, with a higher value representing more resistance to the 

formation of condensation.

WINDOWS

Specify efficient windows to control 

solar energy gains and to help 

reduce heating and cooling loads.

FIGURE 11: NFRC Window Label

Energy efficient windows are 

comfortable to sit near and 

provide protection for furniture 

and window treatments.
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ENERGY STAR qualifies specific windows in addition to qualifying houses. For the 

southern climate region all windows, doors, and skylights qualifying for the ENERGY 

STAR label must have a U-factor rating of 0.75 or below and a SHGC rating of 0.40 

or below. You need not use ENERGY STAR-labeled windows to qualify a total house 

for an ENERGY STAR label.

The Efficient Windows Collaborative operates a web site that can help designers and 

consumers choose windows. The web site includes a tool that allows users to analyze 

energy costs and savings for windows with different ratings. Visit the web site at: 

www.efficientwindows.org/index.cfm.

The web site also has fact sheets with comparisons for each state. These fact sheets 

could make effective marketing tools. Also described on the Web site is a book entitled 

Residential Windows: A Guide to New Technologies and Energy Performance (Carmody 

et al. 2000), which offers homeowners, architects, designers, and builders a fascinating 

look at the state of the art in window technology. Emphasizing energy performance, 

the book covers every aspect of window design and technology: the basic mechanisms 

of heat transfer; new products and rating systems; the effects of window frame material 

and installation; and how to make the best decisions when purchasing windows.

Overhangs

Best Practice: Design roofs with overhangs to shade and protect windows and doors. 

Overhangs may take the form of eaves, porches, or other design features such as 

awnings, pergolas, or trellises.

Single glazing is not recommended, but when a house has clear single glazing, lightcolored interior shades, overhangs, and combinations of shading devices significantly 

reduce energy costs. Naturally, a completely shaded house has the best performance in 

a hot climate.

Reliance on any form of shading is not nearly as important when windows with a low 

solar-heat-gain coefficient are used. Using a low-solar-gain low-E coating results in 

great energy cost reductions for all conditions even with no shading. This is because 

the glazing itself provides the necessary control of solar radiation, so shading measures 

become less important in terms of energy use. For a description of the interactions 

between window performance and shading, see the Efficient Windows Collaborative 

Web site at www.efficientwindows.org.

Overhangs should be sized to account for differences in sun angles, elevation, window 

height and width, and wall height above the window. Free and low-cost computer 

programs and tools are available to help. For example a free program telling you 

the angle of the sun for any point in the country is available at www.susdesign.

com/sungangle/. Latitude, longitude, and elevation data can be obtained at www.

wunderground.com. Overhang dimensions can be calculated at www.susdesign.

com/overhang/index.html. For a listing of free and available-for-purchase energy 

models, including solar design tools, see DOE’s Building Technology Program Web 

site at www.eere.energy.gov/buildng/index.cfm?flash=yes. Click on Software Tools on 

the lower right side. A low-cost sun angle calculator is available from the Society of 

Building Science Educators at www.sbse.org/resources/sac/index.htm.

Overhangs also provide protection from rain, hail, and the effects of overheating and 

ultraviolet radiation on siding and windows.

OVERHANGS

Design roofs with overhangs 

to shade and protect windows 

and doors.

FIGURE 12: Overhangs

Sun angles for Charleston, 

South Carolina. A four foot 

window would need an overhang 

extending 18 inches with 12 

inches of wall above the window.

Winter

Sun

Summer

Sun

34o 77o
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Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Ceilings and Roofs

As indicated earlier, ceilings, roofs, and attics represent complex building assemblies. In 

addition to the sealing and insulation approaches shown in the Air Sealing section, here 

are additional insulation guidelines. These guidelines apply to traditionally ventilated 

attics. Unvented attics must be tightly sealed and are not described in detail in this guide.

• If attic access is provided, it must be insulated and weather-stripped.

• Use baffles to allow ventilation air to freely flow past insulation.

• Install an “energy” truss for more headroom at the eave to avoid compressing 

insulation and allow for consistent attic coverage.

• Use dams to hold insulation away from openings and storage areas. Thick batt 

insulation makes an excellent dam. Waxed cardboard, foam sheathing, and 

other sheet goods can also be used as dams.

• Only recessed lights rated for “insulated ceiling and air tight” (ICAT) should 

be installed in ceilings. See the section on electrical for more information.

Heating, Ventilating and Air Conditioning

Best Practice: For the best results in comfort, efficiency, and durability, HVAC system 

design for both equipment and ducts must be integrated in the overall architectural 

design. Work closely with your HERS rater, HVAC engineer, or HVAC contractor to 

properly design, size, and select your HVAC equipment. If done properly, you will save 

money and go a long way with this single step toward improved energy efficiency and 

comfort and substantial cost savings.

A well-designed house should have an HVAC system properly sized to its demands. 

Proper equipment sizing ensures a comfortable environment and provides opportunities 

to recapture some of the expense of an efficient building envelope. Rules of thumb for 

equipment sizing do not work in modern homes and should not be used.

Unfortunately, rules of thumb are still prevalent. A Florida survey points out some of 

the practices of HVAC contractors (Viera, Parker, Klonbergo, Sonn, and Cummings 

1996). Although only a small percentage of Florida’s HVAC contractors responded, 

the survey found that about one-third of respondents size air conditioning and 

duct capacities based on square footage or other rules of thumb. Compounding the 

problem, the rules were not consistently applied. Some respondents provided twice 

as much capacity as others for a given square footage of floor area. Over one-third of 

respondents indicated intentional oversizing of HVAC equipment on some jobs, in 

order to avoid complaints, accommodate future expansions, enable quicker cooling 

down of homes, and to allow for lower cooling set points by homeowners.

Sizing Air Conditioners

Best Practice: Right size air conditioners and other HVAC equipment.

In addition to wasting energy and money, oversized air conditioning systems in a hot 

and humid climate may cause moisture problems. Besides cooling, air conditioners 

provide the valuable service of removing moisture from the air. If humidity is not 

removed, reducing the temperature will create condensation on cool surfaces and create 

cold, clammy conditions. To compensate for the clamminess, occupants are likely to 

HVAC

Integrate HVAC system design in 

the overall architectural design.

RIGHT-SIZING

Right size air conditioners and 

other HVAC equipment.

Builder GW Robinson of 

Gainesville, Florida, was able 

to go from two HVAC units - a 

5-ton unit for the house and 

a 1.5-ton unit for the bonus 

room – to a 4-ton HVAC 

unit for the whole house, by 

giving extra thought to duct 

layout, specifying duct layout 

on the floor plans and using 

zone dampers and return air 

pathways in each room of his 

up-to 4,500.sq.ft. houses.

“The recommended changes in 

our practices meant we were 

able to downsize our equipment 

by a half-ton,” explains Andrew 

Nevitt, Medallion’s head 

architect. “Our contractors were 

concerned that they’d experience 

increased callbacks because of 

comfort issues.” That hasn’t been 

the case. Medallion is building 

all its homes to reach Energy 

Star performance levels and is 

working with Building America 

to learn practices that will push 

the performance of its homes 

even further. (as reported in 

Professional Builder 3/1/03)
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set the temperature much lower than would be the case if the space were drier, wasting 

energy and causing even more condensation and discomfort. 

In addition to “right-sizing” the unit for optimum comfort, an efficient building 

envelope often allows for downsizing of air conditioning units, further reducing initial 

cost. In larger homes, downsizing may allow one unit to replace two, for additional 

savings in cost and maintenance. These dollar savings can help compensate for the extra 

cost of window and insulation improvements.

One estimate states that a Manual J calculation takes about 30 to 60 minutes for 

an average home, using the measurements from construction drawings. Manual S 

calculations require an additional 15 to 30 minutes (SBIC 2003). A single calculation 

can work for multiple use of the same plans. 

Air Conditioner and Heat Pump Ratings 

Best Practice: Central air conditioners should be rated at a minimum of 13 Seasonal 

Energy Efficiency Ratio (SEER) for air cooling and heat pumps should be rated at a 

minimum of 7.6 Heating Season Performance Factor (HSPF) for heating.

In September 2006 DOE will begin enforcing a 13 SEER standard for all 

residential central air conditioners. For more information on this standard, visit 

www.eere.energy.gov/buildings/appliancestandards. 

Until recently, SEER-10 air conditioning equipment has been standard across the 

country. But SEER-11 and SEER-12 equipment is becoming more widely used. SEER12 equipment is nearly always cost-effective. Consider using SEER-14 air conditioning 

equipment to achieve performance levels greater than 30% savings. Equipment with 

SEER ratings up to 20 are now available. Currently, ENERGY STAR-labeled central 

air conditioners have a minimum rating of SEER 12.

Heat pumps are preferable to electric resistance heating in all but the mildest of 

climates, such as southern Florida, where there are fewer than 500 annual heating 

degree days. A unit with a HSPF of 7.7 or more will reduce the electric consumption 

during heating by more than 50% relative to electric resistance heating. The new 

standard will require that central heat pumps have a minimum rating of 7.7 HSPF. 

RATINGS

Central air conditioners should be 

rated at a minimum of 12 SEER 

and heat pumps should be rated at 

a minimum of 7.6 HSPF.

Four Sources for HVAC Design

The Air Conditioning Contractors of America (ACCA) has published simple but 

effective methods for determining loads and sizing ductwork and heating and 

cooling equipment.

• Manual J tells you how to calculate loads.

• Manual D tells you how to size ducts.

• Manual S guides you through the selection of appropriate heating and 

cooling equipment to meet identified loads.

• Manual T gives you the basics for small buildings.

For more information or to purchase these documents on the web, go to: www.acca.org.

FIGURE13: ACCA Manuals
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Lists of all ENERGY STAR rated appliances can be found at www.energystar.gov/index

.cfm?c=appliances.pr_appliances

Central Gas-Fired Furnace 

Best Practice: Sealed combustion gas furnaces should be specified for central gas-fired 

heating systems. ENERGY STAR labels furnaces that meet a minimum Annual Fuel 

Utilization Efficiency (AFUE) of 90. Lists of all ENERGY STAR-rated appliances can 

be found at www.energystar.gov/index.cfm?c=appliances.pr_appliances

Mechanical Ventilation 

Best Practice: Building America recommends the best practice of integrating mechanical 

ventilation into the HVAC system. Whole house ventilation is a requirement in some 

state building codes.

Central fan-integrated supply ventilation can be an easy and inexpensive way to 

provide outside air to the HVAC system. This system provides fresh, filtered, outside 

air in a controlled amount using the existing HVAC delivery system for 

even distribution and mixing.

Most of the Building America teams have designed and field-tested these 

ventilation systems. The systems involve exterior air intakes, ductwork running 

to the return air side of the HVAC system, dampers to allow control of the air 

intake, and electronic controls to ensure that the HVAC fans operate frequently 

enough to draw in adequate fresh air. For an example of these systems, see 

www.buildingscience.com/resources/mechanical/air_distribution.pdf for more 

detailed information.

VENTIALTION

Integrate mechanical ventilation 

into the HVAC system.

GAS FURNACES

Specify sealed combustion gas 

furnaces for central gas-fired 

systems.

Sealed Combustion

Sealed combustion means than an appliance acquires all air for combustion through 

a dedicated sealed passage from the outside, to a sealed combustion chamber, and all 

combustion products are vented to the outside through a separate, dedicated sealed vent.

FIGURE 14: Outside Vents

Source: Building Science Corporation

Air Intake being installed in a 

porch overhang to provide fresh air 

to attic HVAC.
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Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Supplemental Dehumidification 

Best Practice: Building America recommends that houses be equipped with a 

dehumidification system in the hot and humid climate or designed so that a 

dehumidifier can be easily added. 

One Building America team recommends that all homes in the hot and humid climate 

call for supplemental dehumidification. Other teams call for these systems in homes 

where moisture proves to be a problem.

In an energy-efficient home, there is less demand for cooling. Air conditioners tend to 

run less often and humidity control may require supplemental dehumidification. In 

any home where oversized air conditioners lead to short cycling, the system may not 

provide adequate dehumidification.

Building America scientists field tested six dehumidification systems in Houston. The 

study identified a good supplemental dehumidification system with reasonable costs and 

performance. The system can be installed either during construction or after occupancy. 

The best performing system from the Houston study consists of the following:

• a stand-alone dehumidifier located in the attic in an insulated enclosure 

(if the attic is not conditioned) and ducted to the living space, 

• a dehumidistat located in the living space,

• a fan cycler and an integrated supply of fresh air (see the section on ventilation) 

because moisture control performance is dependent on effective and regular 

mixing of indoor air.

Other systems may work well in circumstances where allergy-sensitive homeowners are 

seeking high-performance air filtration. In all homes, spot ventilation in kitchens and 

bath rooms is critical to humidity control.

ENERGY STAR qualifies dehumidifiers. Energy efficiency is measured in liters of 

water removed per kilowatt-hour of energy consumed. To earn the ENERGY STAR 

label, dehumidifiers must fall within the range of greater than or equal to 1.20 to 1.50 

L/kWh for standard capacity units. The requirement for high-capacity units is greater 

Efficiency Measures for Air Conditioners, Heat Pumps, and Furnaces

The Seasonal Energy Efficiency Ratio (SEER) is a measure of equipment energy 

efficiency over the cooling season. It represents the total cooling of a central airconditioner or heat pump (in Btu) during the normal cooling season as compared to the 

total electric energy input (in watt-hours) consumed during the same period. 

The Heating Season Performance Factor (HSPF) is a measure of a heat pump’s energy 

efficiency over one heating season. It represents the total heating output of a heat pump 

(including supplementary electric heat) during the normal heating season (in Btu) as 

compared to the total electricity consumed (in Watt-hours) during the same period.

The Annual Fuel Utilization Efficiency (AFUE) measures the amount of fuel converted 

to heat at the furnace outlet in proportion to the amount of fuel entering the furnace. 

This is commonly expressed as a percentage. A furnace with an AFUE of 90 could be 

said to be 90% efficient.

DEHUMIDIFICATION

Equip the home with a whole-house 

dehumidification system.
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than or equal to 2.25 L/kWh. Lists of all ENERGY STAR-certified appliances can be 

found at www.energystar.gov/index.cfm?c=appliances.pr_appliances.

More information on the Building Science Consortium’s Houston study of 

dehumidifiers (BSC 2002) is available on the web at www.buildingscience.com/

resources/mechanical/conditioning_air.pdf.

Compact Air Distribution System 

 Best Practice: Make duct runs as short as possible.

An efficient building envelope and 

efficient HVAC equipment allow for 

a compact air distribution system. 

Conditioned air may be discharged 

from inside walls (see the discussion 

in the next section on chase design) 

or from ceiling diffusers up to 12 feet 

from the window wall in most cases 

without compromising comfort. Such 

“inside throw” layouts cut ductwork 

runs, saving money and reducing the 

amount of ductwork that may run in 

unconditioned space.

Seal All Ducts and Air Handlers

Best Practice: Seal all ductwork seams 

and connections to air handlers with 

UL181-approved water-based mastic 

and seal drywall connections with caulk 

or foam sealant.

Sealing ductwork is very important. 

In the hot and humid climate it may 

be the simplest and most important 

step in controlling indoor humidity 

in some homes. Leaky ductwork in an 

unconditioned attic or crawspace can 

draw unhealthy and humid air into the 

air distribution system. Sealing ducts 

with mastic is desirable even for ducts 

located in conditioned spaces. Properly 

sealed ducts make sure air gets to the 

spaces intended, rather than leaking into 

a plenum space. It also minimizes the 

chances of creating pressure differentials 

from space to space that would induce 

airflow through the envelope. The 

process of sealing each joint reduces the 

chances of unconnected ductwork, a 

surprisingly common mistake.

DUCT RUNS

Make duct runs as short as possible. FIGURE 15: Duct Run Configurations

DUCT SEALING

Seal all ductwork and air handlers 

with mastic and seal duct boots to 

sheetrock connections.

Source: Building Science Corporation
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Mastic provides the most reliable duct sealing method for new construction. All ductwork, 

including the air handler compartment (which typically has many leaky joints), should be 

mastic sealed.

DOE research has found that some tapes perform adequately for sealing ducts, particularly 

fiberglass duct board. However, good performing tapes may be difficult to identify and 

traditional duct tape (cloth-backed rubber adhesive tapes) should never be used to seal ducts, 

even if it meets UL ratings. Do not use sealing tapes for structural purposes. Tapes have low 

tensile strength and should not be used to mechanically support ducts. A technical report 

(Walker, Sherman, Modera, and Siegel 1998) on duct sealants can be found on the web at: 

http://ducts.lbl.gov/Publications/lbl-41118.pdf and a less technical article (Sherman and Walker 

1998) on similar research can be found at: www.homeenergy.org/898ductape.title.html.

Ducts and Air Handlers in Conditioned Space

Best Practice: Ducts and air handlers should be placed in conditioned spaces to the 

extent possible. High temperatures and humidity levels can be found in unconditioned 

spaces and create an unfavorable environment for ducts and air handlers.

Ducts and air handlers perform best when placed within conditioned space. Keeping 

ducts inside conditioned space may require one of several strategies, such as:

1) Placing ducts in a chase designed to run through a central corridor below 

the attic or on top of the ceiling through the attic. If the chase runs 

through the attic, it must fit within the roof truss design and will be 

covered with insulation. For more information on designing and building 

an interior chase see the report, Design and Construction of Interior Duct 

Systems (McIlvaine, Beal, and Fairey 2001), available on the web at: 

www.fsec.ucf.edu/bldg/baihp//pubs/interior_ducts.pdf.

A New Standard in Residential Ventilation

In Autumn 2003, the American Society of Heating, Refrigerating And Air-Conditioning 

Engineers (ASHRAE) established a new standard for indoor ventilation in residences. 

The standard is ASHRAE 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise 

Residential Buildings (ASHRAE 2003). The following information is adapted from the 

Standard’s forward:

The standard contains three main sets of requirements and a host of secondary 

ones. The three primary sets involve whole-house ventilation, local exhaust, and 

source control. Whole house ventilation is intended to dilute the unavoidable 

contaminant emissions from people, materials, and background processes. Local 

exhaust is intended to remove contaminants from specific rooms, such as kitchens 

and bathrooms, where pollutant sources are produced. And source control measures 

are included to deal with other anticipated sources. The standard’s secondary 

requirements focus on properties of specific items, such as sound and flow ratings 

for fans and labeling requirements.

The standard is principally about mechanical ventilation, but its purpose is to 

provide acceptable indoor air quality. The most effective way for keeping exposure 

to pollutants low is to keep them from being released to the general indoor 

environment in the first place.

ASHRAE will publish guidance documents on meeting this standard in 2004.

Mastic provides the most reliable duct 

sealing method for new construction.

FIGURE 16: Mastic

“Sealing the ducts with mastic 

is I think the single most 

important thing that anyone 

should do. Sealing gets leakage 

rates down to about 2%. 

Not doing duct sealing on 

new construction is extremely 

short sighted. Mastic will last 

the life of the system, while 

conventional duct tape can fail 

within a year.”

Lucian Kragiel, 

Co-owner of Atlantic Design 

and Construction

DUCT RUNS

Ducts and air handlers should be 

placed in conditioned spaces to the 

extent possible.
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2) Insulating and sealing the underside of the roof sheathing to create a 

conditioned attic. This strategy requires tightly sealing the roof structure, 

especially where it connects with the walls, to avoid the entry of hot moist air. 

This technique essentially requires building a non-vented roof assembly. For 

more information on this technique see www.buildingscience.com/resources/

roofs/unvented_roof_summary_article.pdf

3) Insulating and sealing the exterior walls of the crawlspace so that 

it becomes a conditioned space, such as a mini basement. This 

strategy requires treating the crawlspace much like a living space 

with conditioned air supply, moisture control, and air returns to the 

HVAC system. More information on this approach can be found at 

www.buildingscience.com/housesthatwork/hothumid/montgomery.htm.

Air handlers should be placed inside conditioned space. One approach is to build 

a conditioned closet with sealed access from the garage. In addition to improving 

the efficiency of the equipment, this approach adds additional square footage to the 

conditioned space.

Duct Insulation 

Best Practice: Ducts in unconditioned spaces must be insulated.

To the extent possible, ducts should be placed inside conditioned space. In conditioned 

spaces, they require minimal insulation. If the ducts are placed in unconditioned 

spaces, due to the extreme summer temperatures in these spaces, 10% to 30% of 

the energy used to cool the air can be lost to conduction through the duct surfaces. 

Therefore, they must be insulated. ENERGY STAR recommends the following 

insulation levels for ducts in unconditioned spaces in the hot and humid climate: 

from R-4 to R-8 in attics and R-4 in crawl spaces (EPA 2000, available on the web at: 

www.energystar.gov/ia/new_homes/features/DuctInsulation1-17-01.pdf). 

FIGURE 17: Air Handler 

in Conditioned Space

Standards for Duct Sealants

Underwriters’ Laboratories (UL) publishes several standards that relate to duct sealants, 

the most important of which is UL 181. It deals with ducts in general, with UL 181A 

covering field-assembled duct-board, and the three-year-old UL 181B covering flex duct 

systems. Each standard includes test procedures for sealants. Duct tapes and packing 

tapes that pass UL 181B are labeled “UL 181B-FX.” Mastics can pass 181A or B and 

are labeled “UL 181A-M” or “UL 181B-M.” Foil tapes are designated with a P.

Most tapes that are labeled 181B-FX are duct tapes. Other 181B products are just 

coming onto the market. UL 181A and 181B appear to do a good job of testing for 

safety, tensile strength, and initial adhesion. However, they may not do a good job of 

rating how well sealants seal typical duct leaks or how well they stay sealed under 

normal conditions.

Adapted from Sherman and Walker 1998

INSULATING DUCTS

Ducts in unconditioned spaces 

must be insulated.
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Transfer Grilles and Jump Ducts

Best Practice: Use jump ducts and transfer grills and other return pathways to maintain 

balanced pressure in each room of the house. This practice is especially useful in rooms 

that are often isolated from the rest of the house by a closed door, such as a bedroom.

To maintain balanced pressure, air must be returned from each room to the central 

HVAC equipment. One way to do this would be to add a ducted return from each 

room. However, this would be expensive and consume a lot of space. A more reliable 

and cost-effective approach is to provide a central return and make sure that there are 

transfer grilles or transfer ducts, of adequate size, that allow air to pass from individual 

rooms to the central return even when doors are closed. Florida codes require that the 

differences in static pressure between any two rooms remain below 2.5 Pascals. Figure 

18 illustrates different approaches to creating paths to equalize air pressure and allow air 

to return to HVAC equipment. When designing registers and transfer grills, place them 

high on the wall in areas where furniture may block air movement.

FIGURE 18: Jump Ducts

BALANCED PRESSURE

Use jump ducts and transfer grills 

and other return pathways to 

maintain balanced pressure in each 

room of the house.

FIGURE 19: Jump Ducts

Source: Building Science Corporation

Source: IBACOS
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Draw Duct Layouts on Plans

Best Practice: Clearly identify on plans and drawings the locations, sizes, and types for 

all duct work and registers, including the heating and cooling supply ducts, passive 

return air ducts or transfers, the locations for the mechanical ventilation air inlet (at 

least 8 ft away from any exhausts or condensers), and all exhaust outlets. If chases or 

other spaces are to be dedicated to duct runs, indicate this on the plans.

This level of detail can be referenced in contract documents so you know exactly what you 

will be getting. These documents can provide guidance in the field for proper installation.

Energy Performance and Commissioning

Best Practice: Air conditioners and heat pumps should be evaluated after installation 

with a duct pressure test and, if needed, a smoke test to identify the location of leaks. 

Procedures are discussed in the Site Supervisors chapter.

Building Science Corporation has identified performance testing as a key reason for 

substantial reductions in callbacks (BSC 2003).

Occupant Health and Safety

The following best practices should be included in the house design:

• Base Rate Ventilation: controlled mechanical ventilation at a minimum base 

rate of 15 CFM for the master bedroom and 7.5 CFM for each additional 

bedroom should be provided, as listed in ASHRAE 62.2.

• Spot Ventilation: intermittent spot ventilation of 100 CFM should be 

provided for the kitchen; all kitchen range hoods must be vented to the 

outside (no recirculating hoods). Intermittent spot ventilation of 50 CFM or 

continuous ventilation of 20 CFM, should be provided for each washroom/

bathroom. Fans should be quiet, producing less than 1.5 sonnes.

• All combustion appliances in the conditioned space must be sealed combustion 

or power vented. Specifically, any furnace inside conditioned space shall be 

a sealed-combustion 90%+ (AFUE of 90 or greater) unit. Any water heater 

inside conditioned space shall be power vented or power-direct vented. 

Designs that incorporate passive combustion air supply openings or outdoor 

supply air ducts not directly connected to the appliance should be avoided. 

Gas cooking ranges shall follow the practices described in the second bullet.

• Use sealed-combustion gas fireplaces to eliminate the threat of harmful 

combustion gases from entering the house. All fuel-burning fireplaces should 

have sealed combustion and be properly vented to the outside. If not properly 

vented and sealed, the fireplace can produce harmful combustion pollutants 

that may be emitted into the home, such as carbon monoxide, nitrogen 

dioxide, and sulfur dioxide.

• Provide filtration systems for forced air systems that provide a minimum 

atmospheric dust spot efficiency of 30% or MERV of 6 or higher. MERV 

(Minimum Efficiency Reporting Value) is a measure of an air filter’s efficiency 

at removing particles. A fiberglass panel filter may have a MERV of 4 or 5. 

Critical areas in hospitals may use a MERV 14 filter. Electronic air cleaners 

should be used with caution because the ozone they produce may affect 

sensitive individuals.

DUCT WORK LOCATION

Clearly identify on plans and 

drawings the locations, sizes, and 

types for all duct work and registers.

EVALUATION

Evaluate air conditioners and heat 

pumps after installation.
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• Indoor humidity should be maintained in the range of 25% to 60% by 

controlled mechanical ventilation, mechanical cooling, or dehumidification. 

See www.buildingscience.com/resources/moisture/relative_humidity_0402.pdf.

• Carbon monoxide detectors (hard-wired units) shall be installed (at one per 

every approximate 1,000 square feet) in any house containing combustion 

appliances and/or an attached garage.

• Maximize hard surface areas (tile, vinyl, hardwood) to better manage dust for 

health purposes. For slab-on-grade houses, it also reduces the cooling loads.

• Information relating to the safe, healthy, comfortable operation and 

maintenance of the building and systems that provide control over space 

conditioning, hot water, or lighting energy use shall be provided to occupants.

Mechanicals Management and Appliances

Plumbing 

Water heater efficiency is described by the energy factor rating. The Consumers’ 

Directory of Certified Efficiency Ratings, Gas Appliance Manufacturers Association 

(GAMA) provides a concise listing of energy factors for water heaters of all fuel types at 

www.gamanet.org.

Best Practice: Do not install plumbing in exterior walls. Seal around plumbing 

penetrations in all exterior surfaces, surfaces that border on unconditioned spaces, and 

between floors. Use fire-resistant sealant in plates between floors.

Best Practice: Because of the dominance of warm temperatures in the hot and humid 

climate, water heaters are best kept out of living spaces, where heat losses could add 

to the cooling load. A garage location may also save money by eliminating the need 

for power-vented equipment. Water heaters can be located freestanding or enclosed 

within a closet in the garage. If enclosed, ventilation grills will be needed to provide 

combustion air.

Electrical

Best Practice: Seal around wires penetrating all exterior surfaces, surfaces that border 

on unconditioned spaces, and between floors. Use fire-resistant sealants between floors. 

If recessed downlights are to be used they should be rated for insulated ceilings and 

airtight (ICAT).

PLUMBING SEALING

Seal plumbing penetrations in 

exterior surfaces and keep plumbing 

out of exterior walls.

WATER HEATERS

Keep the water heater away from 

living spaces to avoid adding to the 

cooling load. If it will be located in 

a living space, use a power-vented 

water heater.

ELECTRICAL SEALING

Seal all wire penetrations.

Water Heaters

Water heaters come in many shapes, sizes, and efficiencies. The Oregon Department of 

Energy maintains a list of high-efficiency water heaters that qualify for state tax credits. 

The list contains high-efficiency gas combustion water heaters, instantaneous (tankless) 

water heaters, and water heating heat pumps. You may consider these products for your 

projects. The tax credits only apply to Oregon installations by Oregon taxpayers. See the 

list at: http://www.energy.state.or.us/res/tax/appheat.htm. 

FIGURE 20: Additional Plumbing 

Air Sealing Building Tips can 

be found in the Trades & Cratfts 

Chapter.
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ICAT is a combination of two standards. 

The first is ASTM E283, the standard for 

testing restricted air movement (ASTM 

2004) and the second is Underwriters 

Laboratory standard for direct burial in 

insulation contained in the Luminaires 

standard (UL 1598). The ICAT standard 

originated in the State of Washington 

building code and now, as part of the 

International Energy Efficiency code, covers 

almost 75% of the country’s population. See 

the Trades chapter for Building Tips for 

electricians for more information.

Consider the use of recessed downlights 

and other fixtures that qualify for ENERGY 

STAR labels. Highly energy-efficient recessed 

downlight fixtures that have undergone 

stringent testing are available for purchase 

at the following DOE sponsored website: 

www.pnl.gov/cfldownlights/. The lights 

featured are ICAT rated and hard-wired for 

compact fluorescent bulbs. Fixed prices have been negotiated for the featured fixtures. 

Using compact fluorescent lamps in lighting fixtures will reduce energy usage and 

lower the cooling load.

Appliances

Major appliances meet high-energy efficiency standards using current appliance ratings. 

Only those appliances in the top one-third of the DOE Energy Guide rating scale 

should be selected. (See list at: www.eere.energy.gov/consumerinfo/

energy_savers/appliances.html)

FIGURE 21: Additional Electrical Air 

Sealing Building Tips are available in the 

Trades & Crafts chapter.
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Sources & Additional Information

• Air Conditioning Contractors of America. Manual D: Residential Duct Systems. 

ACCA, Arlington, VA. www.acca.org.

• Air Conditioning Contractors of America. Manual J: Residential Load 

Calculation, Eighth Edition. ACCA, Arlington, VA. www.acca.org.

• Air Conditioning Contractors of America. Manual S: Residential Equipment 

Selection. ACCA, Arlington, VA. www.acca.org.

• American Society of Heating, Refrigerating, and Air-Conditioning Engineers, 

INC (ASHRAE). 2003. ASHRAE Standard: Ventilation and Acceptable Indoor 

Air Quality in Low-Rise Residential Buildings. ASHRAE, Atlanta, GA.

• ASTM 2004. Standard Test Method for Determining Rate of Air Leakage through 

Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences 

across the Specimen. ASTM E283-04.

• ASTM 2003 WK2469 New Standard (Formerly E1465-92) Guide for Radon 

Control Options for the Design and Construction of New Low Rise Residential 

Buildings.

• ASTM. 2002. Standard Practice for Installation of Exterior Windows, Doors, 

and Skylights. ASTM E2112-01.

• Building Science Corporation (BSC). 2002. 10. Case Study Material: 

Conditioning Air in the Humid South. National Renewable Energy Laboratory, 

Golden, CO.

• Building Science Corporation (BSC). 2003. 9. BSC Final Report: Lessons 

Learned from Building America Participation, February 1995-December 2002. 

National Renewable Energy Laboratory, Golden, CO.

• Building Science Corporation. 2003b. 1.C.2.1 Report Expert Meeting 

Summary. National Renewable Energy Laboratory, Golden, CO.

• Building Science Corporation. Undated. A. www.buildingscience.com/

resources/mechanical/advanced_space_conditioning.pdf.

• CARB (Consortium for Advanced Residential Buildings). 2004. NREL/SR550-34560. National Renewable Energy Laboratory, Golden, CO. Available at 

www.buildingamerica.gov

• Carmody, John, Stephen Selkowitz, Dariush Arasteh and Lisa 

Heschong. 2000. Residential Windows: A Guide to New Technologies 

and Energy Performance. W. W. Norton and Company, New York. 

www.wwnorton.com/npb/welcome.htm

• Edminster, Ann, Betsy Pettit, Kohta Ueno, Stephanie Menegus, and Steven 

Baczek. 2000. “Case Studies in Resource-Efficient Residential Building: The 

Building America Program.” 2000 ACEEE Summer Study Proceedings. ACEEE, 

Washington, D.C.

• DOE. 2000. Technology Fact Sheet on Weather Resistive Barriers. 

DOE/GO-102000-O769, Washington D.C. Available on the web at 

www.eere.energy.gov/buildings/documents/pdfs/28600.pdf.
Designers

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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• Lstiburek, Joseph. 2002. EEBA Builders Guide: Hot and Humid Climates. 

EEBA, Minneapolis, MN. www.eeba.org/bookstore.

• Lstiburek, Joseph. 2003. EEBA Water Management Guide. EEBA, 

Minneapolis, MN. www.eeba.org/bookstore.

• McIlvaine, Janet, David Beal, and Philip Fairey, III. 2001. 

Design and Construction of Interior Duct System. Report Number 

FSEC-PF-365-01, Florida Solar Energy Center, Cocoa, FL. 

www.fsec.ucf.edu/bldg/baihp//pubs/interior_ducts.pdf.

• Parker, D.S., J. R. Sherwin and M. T. Anello, 2001. “FPC Residential 

Monitoring Project: New Technology Development — Radiant Barrier Pilot 

Project,” Contract Report FSEC-CR-1231-01, Florida Solar Energy Center, 

Cocoa, Florida. www.fsec.ucf.edu/bldg/pubs/rbs/index.htm.

• Rudd, Armund. 2003. Refrigeration System Installation and Startup Procedures, 

and Air Conditioning System Efficiency. Building Science Corporation, 

Westford, MA. www.buildingscience.com/resources/mechanical/

air_conditioning_equipment_efficiency.pdf.

• Sherman, Max and Iain Walker. 1998. “Can Duct Tape Take the Heat?” 

Home Energy, Berkeley, CA. www.homeenergy.org/898ductape.title.html

• Straube, John. 2001. Canadian Architect. “Wrapping it Up”. May, 2001. 

www.cdnarchitect.com.

• (SBIC) Sustainable Buildings Industry Council. 2003. Green Building 

Guidelines: Meeting the Demand for Low-Energy, Resource-Efficient Homes. 

U.S. DOE. Washington, D.C. document available at www.SBICouncil.org.

• United States Environmental Protection Agency. 1994. Model Standards and 

Techniques for Control of Radon in New Residential Buildings

• United States Environmental Protection Agency. 2000. Duct Insulation: 

Air Distribution System Improvements. EPA 430-97-028. Washington, D.C. 

www.energystar.gov/ia/new_homes/features/DuctInsulation1-17-01.pdf

• United States Environmental Protection Agency. 2001. Building Radon 

Out: A Step by Step Guide on How to Build Radon Resistant Homes. 

www.epa.gov/199/radon/images/buildradonout.pdf.

• Vieira, Robin K., Parker, Danny S., Klongerbo, Jon F., Sonne, Jeffrey 

K., Cummings, Jo Ellen. 1996. “How Contractors Really Size Air 

Conditioning Systems.” Florida Solar Energy Center, Cocoa, FL. 

www.fsec.ucf.edu/bldg/pubs/ACsize/index.htm

• Walker, I., M. Sherman, M. Modera, and J. Siegel. 1998. Leakage Diagnostics, 

Sealant Longevity, sizing and Technology Transfer in Residential Thermal 

Distribution Systems. Lawrence Berkeley Natonal Laboratory, Berkeley, CA. 

http://ducts.lbl.gov/Publications/lbl-41118.pdf

• Yost, Nathan. May 2003. “The Case for Conditioned Unvented Crawl 

Spaces”. Building Safety Journal. www.buildingscience.com/resources/

articles/24-27_Yost_for_author.pdf
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Web Sites Not Included with Published Documents Above

• www.eere.energy.gov/buildings/index.cfm?flash=yes

• www.energystar.gov/index.cfm?c=bop.pt_bop_index

• www.epa.gov/radon/zonemap.html

• www.epa.gov/iaq/whereyoulive.html

• www.gamanet.org

• www.natresnet.org

• www.nfrc.org

• www.efficientwindows.org/index.cfm

• www.ornl.gov/sci/roofs+walls/insulation/ins_16.html

• www.fsec.ucf.edu/bldg/pubs/rbs/index.htm

• www.certainteed.com/pro/insulation

• www.susdesign.com/sunangle

• www.pnl.gov/cfldownlights/
Site Supervisors

Tools to help with project management

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • SUP-1

In the chain of events that results in a finished home, the site supervisor (or project 

manager) has the critical job of turning ideas into reality. The site supervisor’s job is 

to make sure everything happens. Plans must be correct, permits must be in order, 

contracts must be signed, subs must be scheduled, materials must be on site, and it 

all must happen on schedule. Successful construction of an energy-efficient home is 

essentially the same as other homes, although a few details are different and can demand 

more careful scrutiny because of the interdependencies in a systems-designed house.

Site supervisors working to build energy-efficient homes can generally do their jobs 

as they already know how, with a few simple but important changes. There are 

three keys to constructing any quality home—managing expectations, managing 

the schedule, and controlling quality and costs. This section will explain how to 

incorporate those three keys into your construction process.

An energy-efficient home built using these Building America recommendations looks 

a lot like any other home. It will maintain its visual appeal and style. The key points 

at which it differs typically involve more efficient HVAC equipment (including 

ducts), an engineered HVAC system design, a supply of outside air for ventilation, 

humidity control, better windows, better insulation, and better air sealing. The 

Designers chapter contains best practices recommendations on the features 

energy-efficient homes should include. Many builders make the comment that it’s 

not the quantity of changes that make an energy-efficient home, but the quality 

that is put into building the home.

“We found no significant increase in materials costs or in subcontract labor costs. It 

was really more in techniques,” said Walter Hendrix, Executive Director of Troup 

Chambers Habitat for Humanity and Dependable Affordable Sustainable Housing 

for La Grange, Georgia.

Of course, it is not always easy for a site supervisor to control all aspects of a 

subcontractor’s work. It may be necessary, especially while these best practices are 

new ideas, to prioritize activities and “pick your battles.” In hot and humid climates, 

the top priorities are 1) window selection and installation, 2) HVAC sizing and 

installation, and 3) moisture control.

Managing Expectations

A project manager who can foster a set of shared expectations among the important 

players in his or her building team can successfully build efficient houses. Two goals 

should influence the project manager’s actions at the start of the project:

• Make sure subcontractors and in-house workers understand what you want. 

• Eliminate the need for unknowledgeable (and often unskilled) laborers to 

make design decisions. 

The following best practices will help meet these goals.
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Develop a Work Plan

Decide who is going to do what. Will the plumber install insulation behind the tub 

or will the framer, or some other trades person? Develop a schedule for the order that 

activities should occur to be sure that actions are done in a reasonable order and that 

no actions will be forgotten. Be sure that all needed materials are on the site when the 

activity is scheduled to take place. More information on scheduling is included in the 

Managing Execution section.

Plans – Get Them Right

Best Practice: Before starting a project ensure that plans are correct and that you have 

everything you need to go forward. Once you have the plans you need, follow them.

Existing stock plans will likely need to be modified to both include necessary changes 

and to add details not commonly included in residential prints. See the Design section 

for a description of design best practices. 

A well-designed home should have well-designed plans that include everything 

necessary to explain expectations to the subs. Some points that should be included are:

• HVAC design details and duct layout. The duct layout must be included 

on a floor plan. The duct and diffuser sizes, quantities, and locations must 

be installed as specified. Subcontractors should be contractually obligated to 

these specifications. Performance requirements (such as SEER and AFUE) for 

system components should be specified on the plans.

• Framing plan. If advanced framing is to be included in the design, a detailed 

plan is needed showing how advanced framing techniques will be applied. 

These should detail the placement of studs to ensure proper “stacking” in twostory homes and should show details of window and door framing. Advanced 

framing is not required to achieve 30% energy savings in the hot and humid 

climate but is an important money and time saving measure for more highly 

efficient homes.

• Other call-outs or specifications. Call-outs and specifications should be 

written to detail how particular measures will be installed, including both 

the techniques and the materials to be used. Of particular importance are 

specifications and call-outs for items that differ from local standard practice 

such as caulking; draft stops behind bathtubs, stairs, and dropped ceilings; duct 

sealing requirements; gasket materials; window schedules specifying U-factors 

and SHGCs; and product performance metrics. Also call out items that should 

not be done, such as caulking ceiling penetrations under conditioned attics.

Plans — Keep Them Right

Best Practice: Avoid plan changes. When they are required, document the changes as 

you would the original contract.

Numerous difficulties can be avoided with correct building plans. If the plans have 

been properly developed, with the proper sizing of equipment, you must be sure that 

changes will not undo this good work. The practice of verbally communicating changes 

PLANS

Make sure they are correct 

and follow them closely.

AVOID CHANGES

Thoroughly document 

any changes to plans.
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is always risky and is potentially disastrous for a systems-designed home where highperformance features interact to achieve energy efficiency, comfort, and durability. 

Before making any changes ask yourself these questions:

• Why are the changes being made? If there are no clear benefits from the 

change, don’t do it.

• What effect will the change have on building performance? Will the change 

deviate from best practice recommendations? Will you need to change HVAC 

sizing or system selection? If you don’t know the answer to these questions, ask 

your HERS rater. Be sure to adjust all the systems related to the change. 

• Are new drawings or specifications needed to clearly document your 

expectations? Be clear in your expectations.

Contracts – Write Them Down

Best Practice: Prepare or update formal contracts with key subs that clearly show what 

you expect of them and what they can expect from other subs. Relevant call-outs, plans, 

and specifications described in the last section should be referenced in the contracts. If 

the sub is providing materials, list the specific materials that you want. Here are some 

examples of materials that a sub may supply:

• Recessed downlights, which should be air-tight and rated for insulation contact

• Mastic to seal ducts

• High-density fiberglass insulation

• Sealants and caulks to seal penetrations

• Windows are typically ordered along with other major purchases, but if the 

sub is supplying them, be sure they are rated as called out in the plans

• Draft-stopping sheathing.

If you have expectations for a sub, such as sealing certain types of holes, or installing 

insulation in some space that may become inaccessible, be sure these expectations are 

spelled out in the contract. The scope of work should cover things like equipment size, 

duct sizes, identification of who is responsible for sealing which holes, etc. Contract 

specifications and written assignments of responsibility can greatly simplify the ordering 

of materials. Duct installers, for example, will know exactly what kind of duct material 

will be used and how much; and with this knowledge may be able to prefabricate many 

of their assemblies back at the shop, rather than in the field. These pre-assembled pieces 

tend to be of higher quality thanks to the proximity of tools and materials and better 

working conditions in the shop.

Pre-Construction Meeting – Have One

A final strategy to manage expectations among the subs is to hold a pre-construction 

meeting that includes as many of the subs as possible. At this meeting you can 

emphasize the changes in workflow, shifts in responsibilities, and newly introduced 

building details. Tell your subs about your goals for energy-efficient houses.

WORKING WITH SUBS

Always prepare formal 

contracts and be clear 

about your expectations.
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Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Give the subs drawings and instructions on how to accomplish their jobs. Sample 

instructions are included in the Trades section. This meeting will go a long way toward 

helping people to understand their roles and responsibilities. Make sure that your subs 

are aware that you will be conducting inspections and that both the ductwork and the 

building envelope will be tested for air tightness.

It may be necessary, especially when starting your first energy-efficient homes, to hold 

additional training sessions with key subs. More on this is discussed in the Managing 

Quality section below.

Permits – Grease the Skids

A home built according to the instructions contained in this document for the hot and 

humid climate does not violate any provisions of the national model codes or, usually, 

of local regulations. However, many local code officials are unfamiliar with some of 

the recommended construction techniques. It is well worth your while to raise these 

issues yourself before construction begins so that you’re not surprised by a red tag later. 

(Ensuring that the “new” techniques are clearly delineated on the building plans can 

also help flag these issues during plan review rather than during inspection.)

A meeting with the building department before construction is well-advised. Should 

your code official need information in support of any of the new techniques used in an 

energy-efficient home, Appendix III contains several “tear-outs” that may be helpful. 

These cover some of the more common features that surprise many officials and should 

help in assuring your local official that the proposed techniques are both safe and in 

compliance with the model codes.

Managing Execution

If you’ve managed to establish clear expectations with your subs and suppliers, you’re 

almost ready to begin construction. The final parts of the plan involve training subs 

as necessary, scheduling everything, and monitoring progress.

Training

Best Practice: Attend and have your key subs attend a training course on 

systems-designed housing.

One good way to accomplish this may be to let your Home Energy Rating System 

(HERS) provider (see Quality Assurance below) conduct the necessary training. 

Information on general training is available from:

• Building America – www.buildingamerica.gov

• Energy and Environmental Building Association – www.eeba.org

• Building Science Corporation –www.buildingscience.com/workshops/default.htm

• National Association of Home Builders Research Center – www.nahbrc.org

• Southface Energy Institute – www.southface.org

• IBACOS – www.ibacos.com

SYSTEM DESIGNED HOUSING

Be sure to attend a training 

on systems-designed housing.
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Other sources may include regional universities or Cooperative Extension Service 

programs, homebuilder associations, utilities, and codes programs. More specialized 

training is available at the above sources, plus trade organizations, such as:

• Air Conditioning Contractors Association – offers technician certification 

– www.acca.org

• American Architectural Manufacturers Association – offers window 

installation master certification – www.aamainstallationmasters.com

Scheduling

Constructing an energy-efficient home requires careful attention to scheduling. Several 

of the new construction techniques may require changing the order of subs; some 

require (or benefit from) a shifting of responsibilities from one sub to another; and 

some new activities will need to be added into the schedule. Here are some of the more 

important schedule considerations:

• Schedule HVAC rough-in before plumbing and electrical. It is far more 

important for the ductwork to have un-constricted access and pathways than 

it is for wires or pipes.

• If using a conditioned attic, schedule insulating under the roof deck before 

HVAC rough-in. The insulators must be able to do their job without 

tromping on the carefully placed ductwork.

• Don’t forget to schedule for pipe insulation under the slab.

• Be sure to schedule pre-drywall insulation inspections, flashing inspections, 

and envelope and duct pressure tests. Inspect at key points to ensure that 

insulation and envelope sealing take place before areas become inaccessible. 

Inspections are much more likely to happen if scheduled. And subs may be 

a bit more conscientious if they know their work will be evaluated. 

• Be sure to schedule caulking of electrical and plumbing penetrations after 

drywall is completed and the lines have been installed.

Some situations that may require a shifting of responsibilities include:

• If using advanced framing techniques that include two-stud corners and 

floating drywall corners (see the section on wall framing in the Designers

chapter and Appendix III), someone must attach drywall clips. The framer 

is a more likely candidate than the drywall installer.

• Some caulking work needs to be done by the HVAC subcontractor. In 

particular, main supply and return trunks that lead through walls need to 

be caulked by the person connecting them to the equipment. Don’t let the 

drywall finisher do this with mud—it is neither a good sealant nor durable 

enough. Also, all duct terminations, including jump ducts, must be sealed 

when registers are installed.

• Some post-finish caulking can be avoided by having the electrician use 

pre-fabricated air-tight electrical boxes (see the Trades chapter for an 

electricians tip sheet).
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• If installation of windows and housewrap (or other drainage planes) are 

done by different subs, the window installer must be careful to leave flashing 

unattached at the bottom so that the first row of building paper may be tucked 

under it (see the Trades chapter tip sheets for window flashing, house 

wrap, and sealants).

• If you are using insulated headers, the framer will need to install insulation 

inside any double headers (using sandwiched foam insulation). Open headers 

may be left for the insulation contractor.

• Draft stops must be installed behind bathtubs and stairwells on exterior 

framed walls. The framer should do this, but be sure that insulation is installed 

before the draft-stop material goes on.

Quality Assurance

Inspections

Best Practice: Conduct several inspections during the course of construction, always 

conduct pressure tests of both the whole house and the HVAC ductwork, and always 

check AC and heat pump refrigerant charging. Have the house rated by a Certified 

HERS Rater.

Especially when energy-efficient systems-designed housing is new to your subs, you 

should conduct multiple inspections to ensure that the subs have understood what is 

required of them and how to implement it. After the process has become more routine, 

you might get by with just a couple of inspections. One key inspection should occur 

prior to installation of drywall.

The pre-drywall inspection allows you to ensure that insulation and draftstopping have 

been properly installed before they get permanently enclosed. This is also the best time 

to conduct a pressure test on the ductwork. The duct pressure test should be conducted 

with the HVAC contractor present, at least for his or her first several energy-efficient 

homes. If the ductwork fails to meet the pressure criteria, a smoke test will reveal the 

worst leaks. It is crucial that this happen while the ductwork is still visible and the 

HVAC contractor is present to see what the problem areas are.

Duct testing services can be most easily obtained through a Certified HERS rater. 

The rater can also conduct whole-house pressure tests and assist with training. And 

the HERS rating itself can be a valuable marketing tool for an energy-efficient house. 

To identify a certified rater in your area, check the registry at the Residential Energy 

Services Network (RESNET) web site: www.natresnet.org.

The second important inspection comes after completion of the home, including all 

interior and exterior finishes. This pre-occupancy inspection should check for proper 

sealing of electrical and plumbing (fixtures and drywall penetrations), HVAC registers, 

and the HVAC closet. A whole-house air leakage test (aka “blower-door” test) is 

crucial. Again, your HERS provider is the easiest resource for this service, and this is 

when he or she would be rating the home anyway. Also, if your HVAC contractor has 

not done it, a final check of the AC or heat pump refrigerant charge is crucial. Studies 

have shown that failure to check refrigerant charging results in the average system using 

13% too much energy. [Ref: http://hem.dis.anl.gov/eehem/00/001105.html]

INSPECTIONS

Conduct inspections throughout 

the construction process.
Site Supervisors

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

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Energy Efficiency Checklists

A successful energy-efficient building involves many details. It is worthwhile to 

maintain for each house a checklist of important features to keep track of what has 

been done. Although the best checklist is one you’ve made specific to the design(s) you 

are implementing, the following is a good baseline to work from and may be integrated 

with your existing checklists.

SPOT-CHECK INSPECTION CHECKLIST

These items should be checked if possible as they are installed because they may not be 

accessible at the pre-drywall inspection.

 Grading is sloped at 5% away from the house for at least 10 feet. 

Roof drainage is directed at least 3 feet beyond the building.

 A 6-mil polyethylene sheet is installed directly beneath the 

concrete slab, continuously wrapping the slab and the grade beam.

 Roof materials are installed to provide a continuous drainage 

plane over the entire surface of the roof. Wall/roof junctures 

should be appropriately flashed, including kick-out flashing 

at the bottom.

 HVAC system is appropriately sized and installed according 

to plans. No deviations should be made in the field.

 A mechanical ventilation system is installed as specified 

in the plans.

 Each bedroom has a separate HVAC return duct, a transfer grille, 

or a jump duct.
Site Supervisors

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • SUP-8

PRE-DRYWALL INSPECTION CHECKLIST 

Note: Some measures in this list are unnecessary depending on whether the house is 

sealed on the interior (e.g., air-tight drywall) or exterior (e.g., sheathing) of the wall.

 Bathtubs on exterior walls have insulation behind them and 

draftstops installed.

 Dropped ceilings, dropped-soffit cabinets, and stairwells on 

exterior walls have draftstops installed behind them (unless drywall 

was installed prior to framing-in).

 Windows and doors are sealed to framing using caulks, foams, 

backer rod, and/or similar.

 Window flashing is properly installed to shed water.

 All electrical and plumbing penetrations between conditioned and 

unconditioned spaces are caulked or otherwise sealed.

 All recessed lights beneath unconditioned spaces are air-tight and 

rated for insulated ceiling (IC). All kitchen and bathroom fans 

are appropriately rated (capacity and sound) and exhausted to the 

outside.

 All exterior penetrations (exterior light fixtures, phone and other 

service cables, etc.) are sealed with caulk, gaskets, or similar.

 All housewrap seams are overlapped and taped; top and bottom 

edges are sealed past the plates; housewrap is appropriately lapped 

under window flashing.

 Building paper seams are overlapped shingle style to shed water 

and appropriately lapped under window flashing.

 If housewrap is used, all seams are overlapped and taped; top and 

bottom edges are sealed past the plates; housewrap is appropriately 

lapped under the bottom window flashing.

 Batt insulation is unfaced or blown-in insulation is used.

 No vapor retarder is installed on the inside of the walls.

 Ductwork is sufficiently air-sealed as verified by a duct pressure 

test conducted by a HERS rater. Ductwork leakage to the exterior 

should be not more than 5% of the total air handling unit capacity 

(at high speed) when tested at 25 Pa pressure.
Site Supervisors

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • SUP-9

PRE-OCCUPANCY INSPECTION CHECKLIST

 Entry of main supply/return ducts into air handling unit closet is 

appropriately sealed with foam, caulk, or similar materials 

(NOT with drywall mud).

 Plumbing penetrations through drywall are air sealed.

 Electrical switch and outlet boxes are sealed to drywall with 

caulk or gaskets.

 Light fixture boxes are sealed to drywall with caulk or gaskets.

 Bathroom and kitchen fans are sealed to drywall with 

caulk or gaskets.

 Bathroom and kitchen fans are drawing air-tested with a small 

piece of tissue; the fan should hold the paper against the grill.

 Duct boots/registers are sealed to floor or drywall with 

caulk or gaskets.

 Attic hatches and kneewall entries are weatherstripped.

 Refrigerant charge on air-conditioner/heat pump is verified in 

writing by installer to be within specs, using superheat method for 

non-Thermostatic Expansion Valve systems or subcooling method 

for TXV systems; this may require a return visit during warm 

weather.

 The whole-house envelope is sufficiently air-sealed as verified by a 

whole-house pressure test. Air leakage should be tested by a HERS 

rater and should be less than:

 2.5 in2 per 100 ft2 of envelope area (CGSB, calculated 

at a 10 Pa pressure differential), or

 1.25 in2 per 100 ft2 of envelope area (ASTM, calculated 

at a 4 Pa pressure differential), or

 0.25 CFM/ft2 of envelope area when tested at a 50 Pa 

pressure differential.
Trades & Crafts

Professional tips for fast and easy installation

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-1

On the following pages you will find step-by-step, 

easy-to-follow illustrated instructions for implementing 

key energy efficiency technologies.

These Building Tips are designed to be easily duplicated 

and distributed.

• Slab

• Housewrap

• Window Flashing

• Air Sealing - Plumbing

• Air Sealing - Electrical

• Air Sealing - Drywall

• Air Sealing - Glossary

• Fiberglass Insulation

• Masonry Construction

• Radiant Barriers

• Duct Sealing
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-2

NOTE: Rigid slab insulation in hot and

humid climates is typically not economical.

CONCRETE SLAB

SEAL ALL SLAB

PENETRATIONS

MASONRY WOOD FRAMED

GRAVEL BASE

(4-6" deep coarse, no fines)

PERFORATED

DRAIN PIPE

6 MIL. POLYETHELYLENE

VAPOR DIFFUSION

RETARDE

(extends under grade beam)

FOAM INSULATION

(Provides thermal break for slab and

functions as an expansion joint)

RADON REDUCTION

3" PLASTIC PIPE VENT STACK

OPTIONAL BLOWER

SILL GASKET

MEMBRANE

(also serves as capillary break)

METAL TERMITE

FLASHING

ROOF FLASHING

Slabs

Sources & Additional Information

• U.S. DOE Technology Fact Sheet on Slab Insulation (www.eere.energy.gov/buildings/documents/pdfs/29237.pdf).

• Southface Energy Institute Fact Sheets #29: Insulating Foundation and Doors (www.southface.org/home/sfpubs/techshts/

29_insulatefloors4PDF.pdf).

• Southface Energy Institute Fact Sheets #30: Radon-Resistant Construction for Builders (www.southface.org/home/sfpubs/

techshts/30_radonresistantconst.pdf).

• Building Science Corporation: www.buildingscience.com/housesthatwork/hothumid/wood/default.htm
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-3

Housewrap

Sources & Additional Information

• Southface Energy Institute Fact Sheets #8 Air Sealing (www.southface.org/home/sfpubs/techshts/8_airsealing.pdf)

• U.S. DOE Technology Fact Sheet on Air Sealing (www.eere.energy.gov/buildings/documents/pdfs/26448.pdf).

• See also the Building Tips on Air Sealing and Window Flashing

• See: http://construction.tyvek.com/en/productServices/HomeWrap/index.shtml

• Straube, John. 2001. Canadian Architect. “Wrapping it Up”. May, 2001. www.cdnarchitect.com.

Minimize cuts in housewrap and caulk or tape to seal all penetrations

Unroll around house

Fasten flaps of window "T-cut"

to the inside of the framing.

(* See Window Flashing Building Tips)

Seal spigot

at opening

Tape housewrap according to manufacturers specifications at top plate,

band joist, and horizontal seams, and secure with plastic-capped nails

Housewrap should

be overlapped shingle-style

Seal overlap with tape Seal housewrap to foundation

below bottom plate in basement

or crawlspace.

Caulk under housewrap

and seal gap between

electrical box and

sheathing

= Another trade may have completed this step. Confirm with the site

supervisor. If not, and you need to complete the step yourself, ensure

that the necessary materials are available on site.

Seal floodlight

at opening

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

CAULK

CAULK

CAULK

WINDOW

HOUSEWRAP

PLASTIC-CAPPED NAILS

HOUSEWRAP TAPE

SHEATHING

TAPE

HOUSEWRAP CAULK

SILL GASKET
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-4

Window Flashing

>12" >10"

HOUSEWRAP

CUP NAILS

45∞ 6"

6"

CAULK

STEP 1- If Housewrap Has Not Been Installed STEP 1- If Housewrap Has Been Installed

STEP 2 - Sill Flashing STEP 3 - Jamb Caulking

HOUSEWRAP

HOUSEWRA

HOUSEWRAP

HOUSEWRAPSELF-ADHESIVE

WINDOW FLASHING

TAPE

HOUSEWRAP

HOUSEWRA

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

OUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUS

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

The apron should extend at least 10" past the sides of the

window opening, or to the first stud in open wall construction.

Attach only the apron's top edge with cup nails.

Apply at least a 12" flap, or apron, of building paper

or housewrap just below the windows sill.

Install self-adhesive flashing to the sill, ensuring that

flashing extends up jambs at least 6".

One commercial product comes with two removable strips

over the adhesive. Remove the first strip to expose half the

adhesive and apply this area to the sill. Begin pressing in the

middle of the sill and work towards the sides. Remove the

second strip to expose the adhesive that will be used to apply

the flashing below the window to the outside wall.

Tape down the bottom corners of the flashing

Caulk the outside edges of the head and side jambs

Do not caulk across the sill

Install the window using corrosion resistant nails and

following manufacturer's specifications.

If the window sill is close to the sill plate, the apron

can extend all the way to the sill plate.

Above the window opening, cut a head flap and

flip up to expose sheathing, and loosely tape in place

out of the way.

Cut the housewrap covering the rough opening in the

shape of a modified "Y".

Fold the side and bottom flaps into the window

opening and secure.

Example of window flashing details for home with housewrap and plywood or OSB wall sheathing.
Building Tips: Window Flashing

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-5

Sources & Additional Information

• Lstiburek, J.W. (2002). Water Management Guide. Minneapolis, MN: Energy and Environmental Building Association 

(ww.eeba.org). 

• U.S. DOE Technology Fact Sheet on Weather-Resistive Barriers

(www.eere.energy.gov/buildings/documents/pdfs/28600.pdf).

• Standard Practice for Installation of Exterior Windows, Doors, and Skylights. ASTM E2112-01, September 2002. 

West Conshohocken, PA.

CAULK

4" 1"

SELF-ADHESIVE

JAMB FLASHING

EXISTING

APRON

HEAD FLAP SECURED WITH TAPE

STEP 4 - Jamb and Head Flashing STEP 5 - Seal Rough Opening Gap

STEP 6 - If Apron was Installed STEP 6 - If Head Flap was Created

HOUSEWRAP

HOUSEWRAP

HOUS

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP SELF-ADHESIVE

HEAD FLASHING

FOLD DOWN

HEAD FLAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

HOUSEWRAP

SECURED TO

WINDOW FLANGE

WITH TAPE HOUSEW

HOUSEW

HOUSEWRAP

HOUSEWRAP

If housewrap has been installed, be sure that the head flap,

when it is folded down, will cover the top of the flashing.

Install self-adhesive jamb flashing extending 4" above the top

of the head flange and even with the bottom of the sill flashing.

If an apron was installed under the window, slip the housewrap

or building paper under the apron.

Tape the edges where the housewrap meets the window flange

if housewrap is installed after flashing.

If building paper is used, embed the edges in a bead of sealant

where the paper meets the window flange.

If headflap was created, fold it over the head flashing

and tape across the top window flange and the

45o angle seams.

Install self-adhesive head flashing extending 1" beyond

the jamb flashing.

On the interior side of the window, seal gap

between the window and the rough opening with

appropriate sealant.
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-6

Air Sealing - Plumbing

Sources & Additional Information

• Lstiburek, J.W. (2000). Builder Guide Hot-Humid Climates. Minneapolis, MN: Energy and Environmental Building 

Association (ww.eeba.org).

• U.S. DOE Technology Fact Sheet on Air Sealing (www.eere.energy.gov/buildings/documents/pdfs/26448.pdf).

PLUMBING

VENT

WALL

TOP PLATE

SEALANT BETWEEN

GASKET AND PLATE

STAPLES

CAULK/SEALANT

CAULK/

SEALANT

FLOOR INSULATION

PIPE

EXTERIOR WALL

RIM

JOIST

Another trade may have

completeed this step.

Confirm with the site

supervisor. If not, and

you need to complete

the step yourself, ensure

that the necessary

materials are available

on site.

Seal tub penetration

Vent pipe may be eliminated with a vacuum relief in some jurisdictions.

Seal all plumbing and electrical penetrations.

Insulate and airseal behind tub.

Keep pipes out of exterior walls and seal

penetrations through floor.

Seal penetrtations through rim joists.

Be careful not to compress or disrupt floor

insulation, keeping pipe runs parallel and close

to studs leaving more room for insultion.

Prefabricated roof vent pipe flashing can be adapted as air sealing gaskets.

CONTINUOUS BEAD

OF SEALANT OR

ADHESIVE

THIN SHEATHING

AS DRAFT STOP

BEHIND TUB

BLOCKING

CAULK
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-7

Electrical Air Sealing

Sources & Additional Information

• Lstiburek, J.W. (2000). Builder Guide Hot-Humid Climates. Minneapolis, MN: Energy and Environmental Building 

Association (ww.eeba.org).

• U.S. DOE Technology Fact Sheet on Air Sealing (www.eere.energy.gov/buildings/documents/pdfs/26448.pdf).

• See also Air Sealing Building Tips

Ceiling fans should be wired to a wall switch.

Seal all exterior penetrations, such as

porch light fixtures, phone, security,

cable and electric service holes, with

caulk, spray foam, or gaskets - note

that foam degrades in sunlight.

Use air tight outlet boxes

or seal standard boxes.

Seal standard plastic

electrical box at face

to drywall with joint

compound or cover

the plate gasket

with caulked foam.

Seal light fixture boxes to drywall with caulk or foam.

Seal bath fan box to drywall

with caulk or foam.

Caulk/seal/foam all electrical wires penetrating

top and bottom plates of exterior walls.

Run wiring along bottom plate at exterior wall.

NOTE: Some codes require wires to be held up from

bottom plates 6"-8" to protect from future drilling through plates.

Run wiring

along side

of stud at

exterior wall

and along

plates

Recessed light fixtures should be rated for Insulated Ceiling Air Tight (ICAT).

AIR TIGHTNESS

LABEL

AIRTIGHT WIRE

CONNECTION FROM

JUNCTION BOX

AIRTIGHT CAN

EXTERIOR WALL

CAULK

SEAL WIRE

CONNECTION

SEALANT

SUPPORT SHEATHING

ELECTRICAL

PANEL

FLANGE FOR SEALING TO

DRYWALL AIR BARRIER

NAILING

FLANGE

BUILT-IN

GASKET

BUILT-IN

SEALANT

CAULK

CAULK AT WIRE

PENETRATIONS

DECORATIVE

COVER

CAULK

CAULK

STANDARD PLASTIC

ELECTRICAL BOX

AIR SEALED

ELECTRICAL BOX

AIRTIGHTNESS LABEL
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-8

Air Sealing Drywall

MEASURE

FRAMERELECTRICIANDRYWALLERPLUMBERWINDOW INSTALLER

EXTERIOR WALLS

Install gaskets or caulk at top and bottom plates of exterior walls. 

Seal between the bottom plate and subflooring. 

Install gaskets behind coverplates. 

Seal large holes behind bath tubs or stairs with sheathing. 

PARTITION WALLS

Seal the drywall at the intersection with the top or bottom plate. 

Seal penetrations through the top and bottom plates for plumbing, wiring, 

and ducts using fire resistant sealants.  

Knee walls can be insulated and sealed at either the roofline or along the line formed by the 

roof, wall, and floor. Rigid foam insulation, taped at the seams with housewrap tape, can be 

used to seal the backside of the knee wall and the underside of the roof. Sealing along the 

roofline is preferred in new construction.

 

WINDOWS & DOORS

Caulk or glue drywall edges to either framing or jambs. 

Fill rough opening with foam backer rod and caulk (preferred) or low-expanding foam sealant. 

Caulk window and door trim to drywall with clear or paintable sealant.  

CEILING

Seal the junction between the ceiling and walls. 

Whenever possible, use continuous drywall sheets for the ceiling 

and walls to minimize joints to be sealed. 

Seal all penetrations in the ceiling for wiring, plumbing, ducts, and attic access openings.   

*Actual assignments to be made by site 

supervisor. The supervisor may choose to 

work with a sealing specialist instead.
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-9

Air Sealing Glossary

Sources & Additional Information

• U.S. DOE Technology Fact Sheet on Air Sealing (www.eere.energy.gov/buildings/documents/pdfs/26448.pdf).

Caulk

Seals gaps of less than 1/2”. Select grade (interior, 

exterior, high temperature) based on application.

Expanding Spray Foam

Fills large cracks and small holes. Expanding foams 

are messy but useful for filling large holes or cracks. 

The material expands 2- to 3-times in volume after 

application. It comes in one-part cans that require no 

mixing or in two-part systems for larger jobs. It degrades 

in sunlight and users should be careful not to get the 

foam on their skin. DO NOT USE near flammable 

applications (e.g., flue vents). DO NOT USE on 

windows and doors. In large applications, a two-part 

system is used which involves mixing the sealant on site. 

For small jobs, one-part spray cans are used.

Low-Expanding/Non-Expanding Spray Foam

These latex-based spray foams come in one-part spray 

cans. They expand very little or not at all and will not 

pinch jambs or void window treatments. 

Backer Rod

Closed-cell foam or rope caulk. Press into crack or gap 

with screwdriver or putty knife. Often used with caulk 

around window and door rough openings. 

Gaskets

Apply under the bottom plate before an exterior wall is 

raised or use to seal drywall to framing instead of caulk or 

adhesive. 

Housewrap

Installed over exterior sheathing. Must be sealed with 

housewrap tape or caulk to act as an air retarder. 

Resists water, but is NOT a vapor barrier.

Sheet Goods 

(Plywood, Drywall, Rigid Foam Insulation) These 

materials form an air retarder. Air leaks only at unsealed 

seams or penetrations.

Sheet Metal

Used with high-temperature caulk for sealing hightemperature components, such as flues, chimneys, and 

framing. 

Polyethylene Plastic

This inexpensive material for air sealing also stops vapor 

diffusion. All edges and penetrations must be completely 

sealed for an effective air retarder. Poly is fragile, and 

proper placement is climate specific.

Weatherstripping

Used to seal moveable components, such as doors, 

windows, and attic accesses.

Mastic

A thick paste which can be used on all duct materials and 

provides a permanent seal. Seals air handlers and all duct 

connections and joints. UL-181-approved water bars 

mastic is best.

UL-181 or Foil-Faced Tape

Temporarily seals the air handler.
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-10

Fiberglass Insulation

INSTALLING FIBERGLASS BATT INSULATION

ALWAYS:

 Avoid gaps, tight turns, and compression

• Cut insulation to fit snugly in non-standard spaces

• Slit batts to fit around wiring and plumbing

• Notch out around electrical boxes and use scraps 

to fill in behind

 Install long runs first – then use scraps to fill in 

smaller spaces and gaps

 Use unfaced batts in hot and humid climates

 Even if blown in insulation is to be generally applied, 

use fiberglass batts to insulate areas that will be 

inaccessible to the blown in insulation, such as 

behind bath enclosures.

Walls:

 Friction fit the batts in place until covered by drywall 

or sheathing

 Insulate before installing stairs and tubs and other 

features that will block access

Knee Walls:

 Seal knee wall to create a continuous air barrier. Knee 

walls can be sealed following the wall itself and attic 

floor or along the sloping edge of the attic roof. Rigid 

foam insulation, taped at the seams with housewrap 

tape, can be used to seal the backside of the kneewall 

and the underside of the roof. Sealing along the 

roofline is preferred in new construction.

 Insulate and air seal the rafter space along the sloping 

ceiling of the knee wall attic space or insulate and air 

seal the roofline wall and floor.

 Rafters should receive [R-19 or R-30] insulation

 Cover rafters with a sealed air barrier (such as drywall 

or foil-faced hardboard)

 Caulk the barrier to the top plate of the wall below the 

attic space and to the top plate of the knee wall itself

 Seal all other cracks and holes

Ceilings:

 Insulate and seal the attic access door

 Install insulation over IC, AT rated recessed cans

 Ventilation pathways?

 Install insulation baffles

Band Joists:

 Place insulation in the cavities between 

joists and subfloor

 Caulk bottom plate to subfloor

 Caulk band joist to subfloor and plates and insulate

 Caulk bottom plate to subfloor

Under Floor Insulation:

 Metal stays, lathe, or stainless steal wire support 

insulation in joist cavities.

 In new construction it is preferred that crawlspace 

walls are insulated. If underfloor insulation is to be 

used it can be held in place with metal staves, lathe, 

stainless steel wire, or twine.

 If truss systems are used under floors, an approach 

better than batt insulation is to install netting or rigid 

insulation to the underside of the floor trusses and fill 

the joist cavity with blown-in insulation. 

Sources & Additional Information

• Energy Efficient Building Association’s Builder’s Guide 

Hot-Humid Climates, 2000.

• U.S. DOE Technology Fact Sheet on Attic Access. 

• U.S. DOE Technology Fact Sheet on Crawlspace 

Insulation. 

* Refer to the Air Sealing Building Tips
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-11

Masonry Construction

Sources & Additional Information

• Builders Guide to Hot and Humid Climates. 2000. Energy and Environmental Building Association (ww.eeba.org). 

RIGID INSULATION

(minimum 1/2" thick)

WOOD FURRING

(minimum 3/4" thick)

GYPSUM BOARD

MASONRY WALL

SHALLOW ELECTRICAL BOX

(syrface-mounted on

masonry interior)

CONTINUOUS 2X4 HORIZONTAL FURRING

(acting as draft or fire stop; seal all

service/wiring penetrations)

INTERIOR GYPSUM BOARD WITH

PERMEABLE OR SEMI-PERMEABLE FINISH

SEMI-PERMEABLE RIGID INSULATION

(expanded polystyrene, extruded polystyrene,

fiber-faced isocyanurate)

WOOD FURRING

GYPSUM BOARD

CONCRETE

SLAB

LATEX PAINT OR OTHER PERMEABLE OR

SEMI-PERMEABLE INTERIOR FINISH

MASONRY

WALL

SLOPING PRECAST MASONRY

SILL WITH PRE-CAST RIB

TREATED WOOD SPACER/MOUNTING

BLOCK TO SUPPORT WINDOW

SEALANT FORMING

END DAM

WOOD SUB-JAMB

(Positioned towards wall exterior so that

face of interior window frame is flush with

center point of rib in precast masonry sill)

TREATED WOOD

SUB-JAMB

MOUNTING MEMBER

("back-caulked"

SEALANT BETWEEN

MASONRY OPENING AND

TREATED WOOD SUB-JAMB

Semi-vapor permeable rigid insulations used on the interior

of wall assemblies should be unfaced or faced with permeable

skins. Foil facings and polypropylene skins should be avoided.

Wood furring should be installed over rigid insulation; the

rigid insulation should be continuous over the surface of the wall,

except for the 2x4 furring near the ceiling. This blocking attaches

directly to the masonry block and is above the insulation, not behind it.

Electrical boxes can be surface-mounted

eliminating chiseling/chipping masonry ELECTRICAL BOX

WINDOW SILL DRAINAGE

Source: EEBA 9.5

Source: EEBA 9.7

Source: EEBA 9.1
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-12

Radiant Barriers

Sources & Additional Information

• U.S. DOE EREC Brief on Radiant Barriers (www.eere.energy.gov/consumerinfo/refbriefs/bc7.html).

• Southface Energy Institute Fact Sheet #14 Radiant Barriers (www.southface.org/home/sfpubs/techshts/

14radiantbarriers.pdf).

• Southface Energy Institute Fact Sheet #25 Ceiling and Attic Insulation and Ventilation (www.southface.org/home/sfpubs/

techshts/25_insulateceilings_4pdf.pdf).

If installed after roof sheathing,

install from inside the attic by

stapling the radiant barrier to

the bottom of the rafters.

If installed before before roof sheathing, drape the radiant barrier

foil-face down between the roof rafters.

NOTE: Some roof sheathing products have a radiant barrier

preinstalled; in this case, ensure the shiny side faces the attic. Allow the material to droop between

attachment points to make at least a

1 inch air space between the radiant

barrier and the bottom of the roof.

AFTER ROOF SHEATHING

BEFORE ROOF SHEATHING

*FOIL-FACE DOWN*

ROOF RAFTERS

RADIANT BARRIER

*FOIL-FACE DOWN*

RADIANT BARRIER

ROOF SHEATHING

1"

AIR

SPACE
Building Tips

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • TRD-13

Duct Sealing

Sources & Additional Information

• Energy Efficient Building Association Builder’s Guide Hot and Humid Climates, 2000.

• Southface Energy Institute Fact Sheet #2 Ductwork Questions & Answers 

(www.southface.org/home/sfpubs/techshts/2duct_q&a.pdf).

• Southface Energy Institute Fact Sheet #18 Energy Checklist (www.southface.org/home/sfpubs/techshts/checklist.pdf).

* All graphics diagrams courtesy of Southface Energy Institute Fact Sheet #2 Ductwork Questions & Answers.

Mastic is a gooey adhesive that is applied wet. It fills gaps and dries to a soft solid. Mastics may or may

not contain reinforcing fibers, and they may be used with reinforcing mesh tape.

FLEX DUCT BOOTS

AIR HANDLER SUPPLY & RETURN PLENUMS

Mastic or caulk

Mastic

Collar with strap;

mastic on take-off

Mastic or caulk Filter Rack

Mastic to seal

refrigerant and

condensate line

Mastic

Mastic

Mastic

Mastic all corners

of metal plenums

Mastic plenum

to air handler

Mastic exterior of collars

Mastic or tape

exterior of duct board

RETURN

SUPPLY

Mastic collars to

metal plenum on

inside or outside

Never puncture inner

liner. If repair is needed;

install a coupling and

seal properly

Strap inner liner and

outer insulation

Use wide straps to support flex duct

spaced at 5 foot intervals

Run lines straight

using metal elbows at

bends and corners

Mastic

boot seams

Mastic before

attaching flex

duct

REGISTER

Seal

joints

in boots

Seal boots to sheet goods (drywall/subfloor)

with caulk, mastic or spray foam

Seal metal or flex to boot or elbow

and joints in elbow with mastic
Habitat for Humanity

La Grange, Georgia

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE A-1

2003 Jimmy Carter Work Project

Could 1,000 volunteers using donated materials build 22 homes in just 7 days and 

could they build them all to ENERGY STAR standards? That’s just what the TroupChambers Habitat for Humanity of LaGrange, Georgia, did between June 6 and13, 

2003, and every home qualified for ENERGY STAR.

These are the first ENERGY STAR 

homes Troup-Chambers Habitat 

has built and the experience was so 

positive, that Walter Hendrix, Executive 

Director of Troup Chambers Habitat 

for Humanity said “we are incorporating 

ENERGY STAR in every house we build 

from here on out.” 

Troup Chambers Habitat plans to build 

38 homes this year and 30 to 40 per 

year over the next 20 years as part of 

Habitat for Humanity International’s 

21st Century Challenge, an initiative to 

eliminate substandard housing in the 

21st Century. The homes range in size 

from 850 to 1,252 square feet, and with 

2 to 5 bedrooms and 1 to 2 bathrooms. 

Homes range in cost from $45,000 to $57,000 and are sold through a special nointerest mortgage program to low-income families who invest “sweat equity” in the 

construction of their own and other Habitat homes. Habitat affiliates across the 

country built 5,400 houses last year, putting Habitat for Humanity International at 

number 16 on Builder’s list of top 100 U.S. builders.

Hendrix, who took over as president of the Troup Chambers Habitat affiliate in 2002 

after 34 years as a private home builder, said he felt building to ENERGY STAR 

standards produced a better house without a large increase in construction costs over 

their standard construction.

We found no significant increase in materials costs or in subcontract labor costs. 

It was really more in techniques, heavy caulking, ways to keep unfiltered outside 

air from coming in. Quite honestly when I had my own construction firm, I 

had concerns about making the house too airtight. The Building America team 

members educated us on the right way to seal a house to keep humid air out 

and to add mechanical ventilation for fresh air exchange. We did a lot more 

caulking. We used sill seal below the bottom plate, which no one was doing in 

LaGrange. The Building America consultants showed our volunteers how to 

wrap the houses, apply the insulation and foam caulk, and wrap duct joints with 

mastick...The attention to detail far exceeds the standard practice.

“The attention to detail far exceeds 

the standard practice.” 

Walter Hendrix, Executive Director of 

Troup Chambers Habitat for Humanity
Case Study: Habitat for Humanity

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE A-2

While Troup-Chambers Habitat hires subcontractors to install the electrical, plumbing, 

HVAC, and flooring, Hendrix estimates their labor force is 60% volunteer, including 

some who have never done construction before, so construction techniques have to be 

simple enough for even novices to follow.

“The Building America team members from Building America’s Industrialized Housing 

Partnership were extremely dedicated, they brought a lot of experience and intelligence 

to the program,” said Hendrix. “They did insulation installation classes with all the 

house leaders and met on several occasions with HVAC contractors to go through 

equipment, installation, and duct sealing techniques. They were always there to give us 

advice on material purchases and decisions.” 

The importance of air sealing is stressed to the volunteers. A continuous wall air 

barrier is installed consisting of: 

• Sill seal between the slab and exterior wall bottom plate

• Rigid insulation sheathing (over OSB) sealed at all seams and edges

• Tar paper window flashing installed shingle fashion to the sides and bottom of 

the rough opening then sealed to the rigid insulation and the rough opening 

with caulk

• Caulk between the window frame and tar paper flashing (applied to each back 

side of the nailing flange just before each window is set.) 

Habitat receives free rigid insulation from Dow and, for this project, used 1/2” 4’x8’ 

sheets attached with collared nails. A continuous ceiling air barrier is formed by the 

drywall and the top plates of all the walls.

Holes for wiring and plumbing through the rigid insulation, top plates of exterior and 

interior walls, and the ceiling drywall all represent breeches of the house air barrier and 

are sealed with either caulk or expanding foam. Common sites for this type of sealing 

include bathroom and kitchen plumbing and fans, the main electrical panel, outside 

electrical outlets and water faucets, electrical and plumbing runs through top plates, 

and dryer vents. Holes too large for foam sealant are first covered or filled in with 

appropriate materials such as drywall, OSB, or rigid insulation, then the joint 

BUILDER PROFILE

Habitat for Humanity

Where:

LaGrange, Georgia

Founded:

1987

Employees: 

2 part-time employees 

subcontractors and volunteers

Development: 

Jimmy Carter

Work Project 2003

Size: 

22 homes

Square footage: 

850 -1252 sq.ft. 

2-5 bedrooms 

1-2 bathrooms

Price range: 

$45,000 to $57,000

Key Features:

• R-13 batt wall insulation 

with 1⁄2” rigid insulation

• Double-pane, low-e 

windows; U = 0.39, 

SHGC = 0.57

• Programmable thermostat

• Heat pump

• Interior air handler 

closet in two- and fourbedroom homes

• Right-sized 

mechanical system

• R-30 in attic

• Insulated steel doors

Habitat for Humanity: The 16th Largest Builder in the United States

The US has 1,651 active affiliates who have built 5,400 houses in 2002 and 44,617 

houses total since Habitat’s founding in 1976. Habitat for Humanity International is 

ranked number 16 in the Builder Top 100.

Through volunteer labor and donations of money and materials, Habitat builds and 

rehabilitates simple, decent houses with the help of the homeowner (partner) families. 

Habitat houses are sold to partner families at no profit, financed with affordable, nointerest loans. The homeowners’ monthly mortgage payments are used to build still 

more Habitat houses. Habitat has built more than 150,000 houses around the world, 

providing more than 750,000 people in more than 3,000 communities with safe, 

decent, affordable shelter. HFHI was founded in 1976 by Millard Fuller and 

his wife Linda.
Case Study: Habitat for Humanity

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE A-3

can be sealed. 

The rigid insulation serves as both the primary air barrier and the drainage plane in this 

wall assembly so sealing the seams and edges is critical. Tape designed for exterior air/

moisture barrier applications is used because other tapes will fail over time, leaving gaps 

for both air and moisture intrusion. 

The space between the window frame and the rough opening is insulated with strips of 

sill seal or wall insulation (folded length-wise, kraft face to interior, for easy placement). 

Where possible, this insulation is caulked to both the window frame and rough opening 

to back up the air seal on the exterior at the nailing flange. This is complementary to 

the seal at the window flange, which forms an important element of the drainage plane. 

Expanding foam is NOT used because it could cause deformation of the window 

frame and Habitat wanted to teach sealing methods that can be universally applied for 

volunteers’ future work.

Typical wall construction is 2x4, 16” o.c. with R-13 fiberglass batt insulation, OSB, 

and 1⁄2” Dow Styrofoam blue board rigid insulation. All of the houses also have vinyl 

siding. The typical HVAC system in an average Habitat house is strip heating and 

air conditioning. In the ENERGY STAR Habitat houses, heat pumps with efficiency 

ratings of 10 SEER and 6.8 HSPF were installed. Programmable thermostats were also 

installed to provide more accurate control and performance. 

HERS Rating

Each home was tested by a team of Building America Industrialized Housing 

Partnership researchers, Southface Energy Institute staff, and Habitat for Humanity 

International staff and volunteers. The average HERS rating exceeded 86.

“We will build 38 homes this 

year and intend to build 30 to 

40 per year from here on out. 

Our goal is to make everyone 

of our new homes ENERGY 

STAR.”

Walter Hendrix, Executive Director 

of Troup Chambers Habitat 

for Humanity

Careful sealing of the air handler 

closet, including framing in 

the return air grill, sealed leaks 

through open wall cavities that 

could pull hot and humid air 

from the attic.

Heat Pump

COMPARISON TO CONVENTIONAL MEASURES

Less Conventional More

+$400 ADDED COST

+$90 to $135 ADDED COST

Housewrap

-$100 SAVINGS • Not needed with rigid insulation

Right-Sized Heat Pump

-$250 SAVINGS • 1/2-ton reduction

• 2- to 4-bedroom only

• Caulk and sill seal

• For use with rigid insulation from Dow

High Performance Windows

+$20 ADDED COST

Air-Tight Return Plenum

+$30 ADDED COST

Air Sealing

+$34 ADDED COST

+$224-269 ADDED COST

Insulation Tape

COST DIFFERENCE

Air Pathway

Through Wall

HVAC

Platform Careful Sealing Around

Return Air Grill

Source: FSEC
Case Study: Habitat for Humanity

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE A-4

Innovations

The two-bedroom homes include a sealed, interior air handler closet. In the air handler 

closets, the space below the platform was made air tight to provide a continuous path 

from the return air grill to the opening in the air handling unit. The gap between the 

ceiling drywall and the supply duct was filled. Caulk was applied at the edges of the 

bottom edge of the drywall, the bottom plate, and the platform edges.

The LaGrange community was designed as a green-space community with shared 

greenspace available to residents and residential traffic directed behind the homes 

for parking.

Comfort, Durability, and Health

The attention paid to air sealing the house reduces infiltration and drafts, saves energy, 

and improves durability by reducing the movement of humid air through the walls. 

The air paths that are sealed are also the “bug paths” since cockroach dander is among 

the top 10 allergy and asthma triggers in the United States, these air sealing efforts 

are good for occupant health as well. Programmable thermostats allow more accurate 

control and performance. Double-pane, low-e windows reflect infrared radiation, 

reduce energy consumption, and prevent carpets and furniture from fading.

The Bottom Line

When asked about costs, Hendrix said “We found no significant increase in materials 

costs or in subcontract labor costs. It’s mainly the attention to detail, it far exceeds the 

standard practice. Will it cost more? On a typical 3-bedroom house you might realize 

$1,000 in extra cost. The return on that is probably 2 to 3 years to the home owner.”
Atlantic Design

& Construction

Gainesville, Florida

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE B-1

Small Changes Add Up to Big Savings

Atlantic Design and Construction of Gainesville, Florida, was already implementing 

some energy-efficient measures in their new home construction when they heard 

about ENERGY STAR in 1998. By making a handful of changes they were able 

to qualify for the ENERGY STAR rating. In fact, these changes were so effective 

Atlantic won ENERGY STAR’s Small Builder of the Year award in 2000.

The firm, founded in 1985, now 

directly employs 15 full-time employees 

and sells about 50 to 60 homes per 

year. Since 2000, they have built more 

than 300 ENERGY STAR homes.

According to Atlantic president Lucian 

Kragiel, the biggest changes from 

their prior construction methods were 

switching to low-e windows, upgrading 

to a higher efficiency HVAC system 

and water heater, adding fresh air 

intake, and moving the air handler for 

the HVAC system from unconditioned 

space in the garage to conditioned 

space.

To get to the ENERGY STAR level, 

Atlantic right-sized the HVAC system, 

increased the efficiency of the air 

conditioner and the furnace, added 

programmable thermostats, switched 

to R-13 blown-in cellulose instead of R-11 fiberglass batts, and did additional air 

sealing around the interior where walls meet the slab. They also added filtered air 

intake in the eaves ducted to the HVAC to draw in fresh outside air. After winning 

the 2000 ENERGY STAR Small Builder award, they further increased the efficiency 

of the air conditioner and the furnace (and added a variable speed blower) and changed 

to double-pane, low-e windows with a solar heat gain coefficient (SHGC) of 0.35.

Innovations

In Atlantic homes, the air handling unit is located in the equipment room which is 

completely sealed from the garage and attic. A sealed, .90+ AFUE combustion gas 

furnace is used. The plenum and refrigerant lines are sealed to the sheetrock with an 

expandable foam at all seams and penetrations. During equipment set, the supply side 

plenum is affixed and then completely sealed with mastic and pressure-sensitive tape. A 

metal tap installed in the return air plenum at ceiling height is attached to an insulated 

flex duct which is connected to a second tap on the furnace side. As an added bonus, 

the mechanical room is conditioned space, and its area (approximately 15 square feet) 

is added to the total square footage of the home, increasing the home’s value.

“Building America helped us by showing 

us how effective the measures are. Ken 

Fonorow (of Florida Home Energy 

Resources Organization, a Building 

America team member visited us and 

showed us potential energy savings, he gave 

us specifics on how to qualify a home in the 

ENERGY STAR point system. He also did 

the HERS testing for us,” explained Kragiel.

Lucian Kragiel, President of Atlantic Design 
Case Study: Atlantic Design & Construction

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE B-2

Comfort, Durability, and Health:

Atlantic installed a simple, non-mechanical fresh air system that introduces filtered, 

outside air to the return side of the plenum. The air handler (which circulates heated or 

cooled air in the home) draws approximately 25 cubic feet per minute of fresh, filtered 

air from a register located under the eaves on the exterior of the home. This creates a 

positive pressure in the home when the air handler is running and helps restrict the 

uncontrolled entry of hot, humid, pollen-laden air into the home. Programmable 

thermostats allow more accurate HVAC control and performance. Double-pane, lowemissivity windows reflect infrared radiation, reduce energy consumption, and prevent 

carpets and furniture from fading. All ducts are coated with an anti-microbial lining 

that resists mold and prevents particles of duct board from entering the air stream.

When the air handling unit (AHU) 

is placed in the garage in a hot 

and humid climate, many negative 

consequences can occur. Accelerated 

rusting in the ferrous heat exchanger 

and increased evaporator coil sweating 

are both more likely due to the humid 

environment and both can shorten 

the life expectancy of the heating 

and cooling system. Air leakage can 

introduce the home to moisture, 

outdoor irritants, automobile exhaust, 

and toxic fumes from substances 

stored in the garage. Ductwork creates 

an unfiltered pathway for hot, moist 

air, and/or pollen-laden outside air to 

enter the home. Atlantic takes care of 

these problems by enclosing the air 

handler in conditioned space in the 

equipment room.

BUILDER PROFILE

Atlantic Design 

& Construction

Where:

Gainesville, Florida

Founded:

1985

Employees: 

15 full-time employees

Development: 

Mentone

Size: 

342 Single-family homes

Square footage: 

1500 - 2600 sq.ft. 

3-5 bedrooms 

2-3.5 bathrooms

Price range: 

$130,000-$300,000

Key Features:

• Double-pane, low-e 

windows; SHGC = 0.35

• R-30 unfaced 

ceiling insulation

• R-13 blown-in 

cellulose insulation

• Right-sized air conditioners 

with SEER 13

• Natural gas heating 

with AFUE = 0.92+

• Natural gas water heating 

with 0.57 efficiency

• Sealed combustion

• Outside air with pressure 

balanced return air

• Duct leakage @ 25 Pa 

<5% of fan flow

• Programmable thermostat

• Air loc recessed lighting

HERS Rating and Testing

A licensed, third-party contractor performs final testing and commissioning 

on each home. The average HERS rating is between 89 and 90.

To qualify as an ENERGY STAR® home the building must be at least 30% more energy 

efficient than a house built to the minimum requirements of the model energy codes, 

the HVAC system must be properly sealed and a “blower door” test must be performed. 

During this test the home is pressurized and air leakage is measured. To pass the blower 

door test a home must have an air change rate of less than 35%. That means that in the 

course of one hour, no more than 35% of the air in the home will be replaced by outside 

air through the natural leakage of the structure under average atmospheric conditions. 

Mentone homes have an average air change rate of 20%.

The Importance of Mastic

Little changes can make a big difference. 

“Sealing the ducts with mastic is I think 

the single most important thing that 

anyone should do,” according to Atlantic 

Design’s president Lucian Kragiel. 

Kragiel estimated that average duct 

leakage in new construction in Florida 

is 10%, and in older homes it is closer 

to 30%. “Just sealing ducts on existing 

homes could reduce the need for new 

power plants. Sealing gets leakage rates 

down to about 2%. Not doing duct 

sealing on new construction is extremely 

short sighted. Mastic will last the life of 

the system, while conventional duct tape 

can fail within a year,” said Kragiel.
Case Study: Atlantic Design & Construction

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE B-3

ENERGY STAR® as a Sales Tool

Atlantic started building ENERGY STAR homes in 1998. They offer ENERGY STAR 

as an upgrade, and so far they have had 100% participation—all of these homes are 

ENERGY STAR. “We show people the wisdom of ENERGY STAR construction and 

the economics of it and everyone chooses it,” said Kragiel.

“It’s not hard to sell when you educate the 

buyer, if you can show them (the buyer) that 

they will get lower utility bills. And they are 

also going to get a higher resale value on their 

house,” said Kragiel. Atlantic tells buyers that 

the EPA has partnered with several national 

mortgage lenders to offer mortgage rate 

incentives for ENERGY STAR home buyers. 

Atlantic also makes buyers aware of lenders 

offering more liberal qualifying requirements 

for ENERGY STAR mortgages, which allows 

buyers to qualify for larger homes or additional 

upgrades. Atlantic made arrangements with 

its preferred lenders to offer a mortgage rate 

incentive of a 1/8 % reduction for ENERGY 

STAR purchases.

Atlantic tells home buyers that every home is individually HERS tested. Upon 

successful completion of testing, the home will receive a Certificate of Authorization 

from the Environmental Protection Agency that is fully transferable, which Atlantic 

says will give their home 

higher market value 

at resale.

Even though Atlantic has 

had 100% participation 

in ENERGY STAR, they 

continue to sell it as an 

upgrade option rather 

than as a standard feature. 

“We think it increases its 

value to the buyer. When 

it’s automatically included 

there may be some doubt 

of its value, but when it’s 

optional and you can tell a 

prospective buyer you’ve had 

100% participation, that 

shows its value. Plus offering 

it as an option gives us an 

opportunity to talk about 

it,” said Kragiel.

The design calls for deep overhangs, which keep sun off 

windows to keep the home’s interior cooler. Doublepane, low-emissivity windows also help keep things cool 

by reflecting infrared radiation and reducing energy 

consumption. This photo shows additional building details 

like flashing between the wall and roof and building paper, 

which provides protection against moisture. Atlantic also 

added additional air sealing around the interior where the 

plate meets the slab.

Atlantic Design & Construction 

received the Energy Star 2000 

Small Builder of the Year 

Award for its energy-efficient 

construction.

Why ENERGY STAR® Makes 

Good Sense for Home Buyers

Atlantic cites these benefits:

• At least 30% more energy 

efficient than standard homes 

• Lower ownership costs / 

higher resale value 

• Mortgage rate incentives 

• High return on investment 

• Qualify for a larger home 

• Improved indoor air quality

“You can make money doing it, 

and you can feel better about 

your self at the end of the day, 

knowing you’re making the 

planet healthier by building 

better homes.”

Lucian Kragiel, President of 

Atlantic Design and Construction
Case Study: Atlantic Design & Construction

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE B-4

The Bottom Line

Kragiel said Atlantic’s costs to implement ENERGY STAR are about $1700 per home 

and they sell the upgrade to home buyers for $2200. “You can pick and choose from 

several options what features you want to add to meet the ENERGY STAR point score. 

We aim for a high score but just making it at all is an improvement. Our ENERGY 

STAR upgrade costs $1700 but it (ENERGY STAR criteria) could be met for about 

half that,” said Kragiel.

Kragiel advises builders to educate yourself first and 

then the buyer. “It (ENERGY STAR) is easier to 

do than you think. Buyers really do want it when 

they understand it. ENERGY STAR is becoming 

increasingly well known. Builders who don’t do it, 

will lag behind,” said Kragiel.

Kragiel notes that it takes a little time up-front to understand how you’re going to 

implement ENERGY STAR and why you’re doing it. Atlantic worked with consultants 

from the Industrialized Housing Partnership of Building America to learn about 

ENERGY STAR. “Ken Fonorow approached us and showed us the sense in it. We’ve 

always been concerned about the environment and making a better product,” said 

Kragiel. “Building America’s ideas fit in with our corporate philosophy. It’s a good 

thing to do.” And the rewards are concrete: 100% of their buyers purchase the $2,200 

upgrade and they’ve had very few callbacks on the ENERGY STAR features. According 

to Kragiel, the biggest benefit is the sense of satisfaction of doing something good. 

“You can make money doing it, and you eel better about yourself at the end of the day, 

knowing you’re making the planet healthier by building better homes.”

“Our experience with ENERGY 

STAR has been absolutely 

positive...Sales are going great.”

Lucian Kragiel, President of 

Atlantic Design and Construction

This outside vent located under 

the eves provides filtered fresh air 

to the return side of the plenum, 

enabling the air handler to 

drawsapproximately 25 cubic feet 

of fresh air per minute.
GW Robinson

Gainesville, Florida

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE C-1

Healthy homes for a healthy bottom line - this could be the motto for GW Robinson 

Builder of Gainesville, Florida. GW Robinson’s efforts to build houses that are healthy 

for the environment and the homeowner are paying off in healthy sales as well.

CobbleField is an in-fill 

development of 290 singlefamily homes on 120 acres 

of woodland just west of 

Gainesville. The developer won 

over local opposition with its 

environmentally friendly design 

that includes placing homes to 

maintain as many existing trees 

as possible and landscaping with 

indigenous species. The homes, 

which range in size from 1800 

to 4500 square feet, with 3 to 

5 bedrooms and 2 to 5 bathrooms, have energy-saving features throughout. Every 

home is also equipped with water-saving features including an irrigation system using 

recycled water and circulating loop hot-water pipes. During building, construction 

debris is recycled whenever possible to reduce trips to the landfill.

While doing their part to help save the planet, 

CobbleField homeowners can breathe easier knowing 

the indoor air quality in their homes is better than 

most thanks to low-VOC paints; non-toxic cellulose 

insulation; coated ductwork to reduce mold, mildew, 

and fungus; arsenic- and chromium-free wood, and 

“Air-Loc” recessed can lights that keep moisture and 

microorganisms out of living areas. The high-efficiency 

HVAC with engineered duct system, fresh air intake, 

and programmable thermostats provides improved air 

quality, better dehumidification, quieter operation, 

maximum air circulation and air filtration, less drafts, 

and more even temperature distribution.

Innovations that Set GW Robinson 

Apart from the Competition

Details like these help give Robinson the edge in the 

competitive $200,000 to $600,000 price range where 

CobbleField homes sell. Robinson quotes Ken Fonorow 

of Florida Home Energy and Resources Organization, 

and a Building America Industrialized Housing 

Partnership team member, in its marketing literature 

saying “Homeowners are now beginning to understand 

the relationship between indoor air quality and their 

Robinson uses non-toxic 

blown-in cellulose insulation 

for more even coating over 

uneven surfaces. Here 

builders have pre-insulated 

in an area that will be 

inaccessible later. The ruler 

will show how thick the 

added insulation is. The 

reflective layer is a radiant 

barrier in the roof that 

reflects 95% of infrared 

radiation and keeps the attic 

up to 30 degrees cooler.
Case Study: GW Robinson

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE C-2

health. At CobbleField, the homes have 

been designed to reduce the introduction of 

pollen, to insure that gases, such as carbon 

monoxide, do not enter the home, and to 

reduce the growth of molds and mildews.”

Building America helps builders identify 

design features like these that boost a 

home’s energy performance and provide 

homeowners with the daily benefits they 

will notice, and mention to their friends. 

For example, Robinson uses a 50-gallon 

natural gas hot water heater that has a 

circulating loop which provides almost 

instantaneous hot water from every faucet 

in the house, while saving water and 

natural gas. (Hot water lines under the slab 

foundation are insulated for extra energy 

savings.) Double-pane, low-emissivity 

windows reduce energy consumption while 

they reflect infrared radiation, minimizing 

glare and heat gain inside and preventing 

carpets and furniture from fading. Inside 

walls containing plumbing are sound 

proofed with R-11 cellulose insulation. A 

radiant barrier in the roof reflects 95% of 

infrared radiation and keeps the attic up to 

30 degrees cooler.

“When we started constructing homes to Building America standards, we realized that 

we were undertaking a whole new way of home building,” says company founder GW 

Robinson. “At first it was a challenge, but now I can’t believe we ever built any other 

way. You have to pay attention more, to think more about the decisions you’re making. 

Now that we’ve built 25 homes to this standard, I can honestly say that we’ll never go 

back. This systems approach just makes more sense.”

Highly Efficient Homes

CobbleField homes have many energy-saving 

features: high-efficiency windows, above-code 

insulation levels, extra attention to duct sealing, etc. 

But the builder has added some innovations to make 

significant gains in energy efficiency.

BUILDER PROFILE

GW Robinson

Where:

Gainesville, Florida

Founded:

1968

Employees:

22 full-time employees;

225 subcontractors and 

related service workers

Development: 

CobbleField

Size: 

290 homes

Square footage: 

1,800 - 4,500 sq.ft. 

3-5 bedrooms 

2-3.5 bathrooms

Price range: 

$190,000 to $600,000

average cost at $400,000

Key Features:

• TechShield 7/16” OSB 

radiant barrier roof sheathing

• Double-pane, low-e 

windows, SHGC = 0.21

• R-30 green fiber blown-in 

cellulose in the ceiling

• R-13 green fiber blown-in 

cellulose in the walls

• Air handling unit in 

conditioned space

• 13 SEER air conditioner

• Hot water recirculation 

loop system

• Engineered duct system

• Opposed Blade Damper 

registers 

• Return air pathways

• Right-sized mechanical system

• Recycled water irrigation system

• Ground underslab pretreated 

against termites.

“We are taking an approach of wanting to 

build a better product in all areas—energy 

efficiency, indoor air quality, no moisture 

problems, and one that is sensitive to the 

environment.” Building America builders 

like GW Robinson are coming up with 

creative solutions like installing irrigation 

systems that use recycled water . Robinson 

is thinking efficiency right down to the 

plants they choose for landscaping, selecting 

indigenous plants, drought resistant 

species, grouping plants with similar water 

requirements, and laying sod in continuous 

areas only to further minimize water use.

GW Robinson conducts blower door tests of every 

completed home to check air tightness. Robinson’s 

CobbleField homes have an average HERS rating 

of between 89 and 90, making them 50% more 

efficient than standard construction.
Case Study: GW Robinson

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE C-3

Special attention was given to the HVAC and duct system with a right-sized, highefficiency 13 SEER air conditioner and engineered ductwork system specifically 

designed for efficiency. All floor plans actually have the duct layout on them and no 

deviation from the layout is allowed by installers. HVAC registers have opposed blade 

dampers that put the air where it’s most wanted and needed. Return air pathways are 

located in every room in the house. Programmable thermostats allow more accurate 

control and performance.

Zone dampers are used, enabling one HVAC system to heat and cool the whole house 

rather than adding separate systems to handle spaces such as bonus rooms. For example, 

instead of using a 5-ton system for the house and a 1.5-ton unit for the bonus room, a 

single, 4-ton unit is sufficient. The zones are generally set up with one for the master 

bedroom suite, one for the formal living area, one for the living area, and one for the 

bonus room.

In addition to meeting ENERGY STAR 

criteria, CobbleField also meets the Florida 

Green Home Standard. To be certified Green 

Homes, CobbleField was constructed with 

specific requirements within categories of 

protecting ecosystems and conserving natural 

resources, creating a green circulation system, 

employing green utilities practices, providing 

resource-driven amenities, operating under 

existing covenants and deed restrictions, and 

providing educational information to help 

achieve and promote green living practices.

Building America—“The Way All Homes Should be Built”

Building America’s philosophy struck a chord with Robinson. “CobbleField is our first 

development to implement Building America building practices. All 290 homes will 

be Building America. It’s not an upgrade option. We are saying, ‘This is a Building 

America development.’ This is the way all homes should be built.” Robinson added, 

“Building America will be offered in our future developments. We need to tackle every 

single issue, not just a few.”

The Bottom Line 

“Our goal is to be number one in our area in that market. If it (Building America) 

didn’t work I wouldn’t use it,” said Robinson. 

G.W. Robinson targets a return on investment (ROI) of 10%. The lower monthly 

operating costs of these homes are recognized by lenders in two ways: 1/8 point 

discounted mortgage rates from certain lenders and buyers qualify for higher priced 

homes because lower energy bills mean homeowners can afford higher mortgage 

payments. Overall, higher sales prices give the developer more profit headroom from 

which to derive ROI.

Robinson offers solar water heaters 

as an option on its homes.

Keeping the Bugs Out

Anybody who lives in the 

hot and humid climate 

knows bugs love it too. 

GW Robinson builds in 

features to keep bugs out. 

Walls and ceilings are 

insulated with naturally 

bug-resistant Green 

Fiber blown-in cellulose 

insulation – R-13 in the 

ceiling and R-30 in the 

walls. The soil underneath 

the slab foundation is 

pretreated with a boron 

mixture to prevent 

subterranean termites.

 “At first it was a challenge, but 

now I can’t believe we ever built 

any other way. You have to pay 

attention more, to think more 

about the decisions you’re making. 

Now that we’ve built 25 homes 

to this standard, I can honestly 

say that we’ll never go back. This 

systems approach just makes more 

sense.”

GW Robinson, President of GW Robinson
Medallion Homes

San Antonio, Texas

MANAGERS

Putting building science to

work for your bottom line

INTRODUCTION

Taking action in your community

CASE STUDIES

Bringing it all together

DESIGNERS

Well-crafted designs capture benefits

for builders, buyers, and business

SITE PLANNERS

& DEVELOPERS

Properly situated houses pay big dividends

SITE SUPERVISORS

Tools to help with project management

TRADES & CRAFTS

Professional tips for fast

and easy installation

MARKETERS

Energy efficiency delivers the

value that customers demand

HOMEOWNERS

Shopping for value,

comfort, and quality

HOT & HUMID CLIMATE ZONE

Hawaii Puerto Rico

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE D-1

They’re Getting Better All the Time

Medallion Homes, three time winner of National Association of Home Builders’ 

Energy Value Housing Award and winner of their Builder of the Year Award in 2000, 

has been building ENERGY STAR homes since 1999. The San Antonio builder 

incorporates ENERGY STAR features 

like high efficiency condensing 

units, low-E windows, and building 

airtightness measures in every home 

it builds as standard features.

In 2001 Medallion partnered 

with Building America’s IBACOS 

(Integrated Building and 

Construction Solutions) to see how it 

could improve energy efficiency and 

construction quality. The result was a 

2400 square foot pilot house built in 

Universal City, a San Antonio suburb. 

Key energy-saving features of the 

Universal City home include 

the following:

• The house was designed and 

built with one HVAC unit inside 

conditioned space rather than 

two systems in the attic (as is the 

typical case for this model). This 

optimization took into account a detailed energy analysis of heating and cooling 

loads. A variable speed furnace (80% AFUE) and high-efficiency condensing unit 

(12 SEER) were used. Cooling capacity requirements were reduced from 5 tons 

to 3.5 tons.

• To improve building airtightness, a great deal of emphasis was placed on 

draftstopping holes to ensure air barrier continuity. With a strict airtightness goal 

it was important to minimize the number of penetrations in the exterior shell.

• Air distribution was optimized through a carefully detailed and engineered duct 

layout that focused on keeping all of the ductwork within the conditioned space 

of the house. Ductwork serving the second floor was located in a bulkhead 

constructed in the second floor ceiling space. Ductwork sealing to reduce air 

leakage focused on the use of UL 181 approved water based mastic.

• A supply side mechanical ventilation system ensures better indoor air quality on 

a continuous basis. The furnace operates continuously on low speed and draws in 

outdoor air through a duct connected to the return air plenum. The amount of 

outdoor air is fixed at 60 cfm by the constant airflow regulator installed.

The home achieved a HERS score of 90.3, exceeding the target of 90.

Award Winning

Medallion won the National Association 

of Home Builders and Professional Builder 

magazine’s Best in American Living Award 

for “Best Affordable Home in the Nation” 

with its energy efficient Craftsman plan. 

Medallion is also three time winner of 

NAHB’s Energy Value Housing Award 

and winner of their Builder of the Year 

award in 2000.
Case Study: Medallion Homes

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE D-2

Lessons Learned

HVAC Optimization

All of Medallion’s homes larger than 2,300 sq.ft. typically have two mechanical 

systems located in the attic. One serves the second floor, the other serves the first floor 

and ductwork for both is located in the attic, where it is exposed to extreme outdoor 

conditions. Bringing the mechanical equipment and ductwork inside the home reduced 

the home’s load and energy consumption by almost 25%. This one improvement alone 

can enable Medallion Homes to downsize from two mechanical systems to one system 

on houses in the 2,300 to 2,800 square foot floor range.

IBACOS worked closely with Medallion’s design staff and mechanical contractor to 

develop a comprehensive duct system design. Since cooling is the priority, all supply 

and return diffusers throughout the home are located in the ceiling or high on the 

walls. For this particular design, the best location for a mechanical closet was on the 

first floor between the house and garage. From this location, ductwork for the first floor 

spaces was integrated into the floor structure for the second floor. All of the diffusers 

for the first floor are located in the ceiling.

A bulkhead was created above bathrooms and closets on the second floor, to create 

a duct distribution plenum for the second floor spaces. The second floor ceiling was 

raised to 9’0”, while the ceiling at the bulkhead was dropped to 7’8”, leaving more 

than 12” for duct distribution. The majority of the diffusers for the second floor are 

located at high sidewalls, at the edges of the bulkhead. The diffusers are accurately sized 

to ensure that the conditioned air is thrown across the length of the room to generate 

good mixing of all the air in the room.

Implementing a new design in the 

field proved challenging—many of the 

flex duct runs were severely pinched 

by framing members at the secondary 

plenum in the second floor ceiling 

bulkhead. The solution involved 

installing a ductboard supply trunk 

running horizontally through the 

bulkhead in the second floor, almost 

the entire length of the house. All the 

supply duct runs came off this trunk 

at locations near each diffuser. Ducts 

were sealed with UL181 approved 

water based mastic sealant. 

A high efficiency condensing unit and furnace with a variable speed blower 

complemented the duct layout. The furnace can operate on low speed when no 

conditioning is called for and distribute the fresh outdoor air provided by the 

mechanical ventilation system. Due to cost considerations, a zone control system 

was not installed.

The only thermostat for the home resides in the study on the second floor. To 

control the high humidity of San Antonio, a Carrier programmable thermostat with 

dehumidification control was installed; the ThermidistatTM can vary the run-time and 

airflows of the cooling system to provide maximum latent load removal.

BUILDER PROFILE

Medallion Homes

Where:

San Antonio, Texas

Founded:

1995

Employees:

TBD full-time employees;

TBD contractors

Development: 

TBD

Size: 

250 homes annually

Square footage: 

1,537 - 2,404 sq.ft. 

3 bedrooms 

2-2.5 bathrooms

Price range: 

$110,000 to $200,000

Key Features:

• Radiant barrier on the roof

• Double-pane, low-e 

windows, SHGC = 0.41,

U-Factor = 0.25

• R-30 U.S. Green Fiber 

blown-in cellulose in 

flat ceilings, R-19 in 

sloped ceilings

• R-13 U.S. Green Fiber 

blown-in cellulose in 

the walls

• 12 SEER HVAC

• Engineered duct system

• Right-sized 

mechanical system

The final duct installation incorporated a 

horizontal duct board trunk in the bulkhead with 

flex duct runs perpendicular to this main trunk.
Case Study: Medallion Homes

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE D-3

Mechanical Ventilation

Since Medallion Homes began working with IBACOS in 1998, they have installed 

mechanical ventilation systems in all of their homes. Initially, these were dedicated 

exhaust fans in the laundry/utility rooms. Exhaust ventilation is not the preferred 

ventilation system in a hot, humid climate and further testing revealed that many of 

these fans were not actually moving any air. Therefore, IBACOS recommended a new 

ventilation system for this pilot home, hoping to find a high performance, cost-effective 

solution for all of Medallion’s houses.

When the furnace fan operates, fresh air will be drawn into the house through the 

fresh air duct, mixed with house air in the return plenum, pulled through the pleated 

media filter, conditioned by the central system, and then distributed throughout the 

house. The fan was be set to run continuously at low speed whenever the thermostat 

is not calling for conditioning. At this low speed setting, the furnace fan moves about 

500 cfm of air while using about 100 W of electrical power. This is less power than 

most energy recovery ventilation systems or heat recovery ventilation systems, so it is 

an economical option for providing ventilation air. A 5” round duct was routed from 

a fresh air intake at the second floor band joist and connected to the return plenum 

near the furnace. This fresh air duct has been equipped with a 60 cfm constant airflow 

regulator, which will maintain a flow of 60 cfm of fresh air whenever the furnace fan is 

operating, even at varying speeds. 

Building Airtightness

Air sealing measures include sealing all penetrations in exterior walls and at the 

insulated ceiling with expanding foam sealant. All windows and doors are also sealed 

with low expansion foam. In addition, window frames are silicon sealed and wrapped 

with moisture-resistant barrier tape. The KeyTM Sealing System, a polycel foam, is used 

to seal exterior penetrations 

(e.g., vents, electrical outlets and 

door jambs). All bottom plates 

are caulked to the subfloor, and 

the drywall functions as the 

main air barrier in the homes. 

IBACOS suggested sealing at the 

furnace/mechanical equipment 

and at the registers and specified 

draftstopping for the walls 

behind, and the lid above, the 

direct vent fireplace unit and 

behind the tub and shower 

surround. Draftstopping is now 

included in all Medallion homes.

The pilot house included a programmable thermostat with dehumidification control. 

Medallion currently offers these features as an upgrade.

A fresh air intake duct with a 

Constant Airflow Regulator runs 

from the outside to the return 

plenum. The furnace operates 

continuously on low speed to 

provide whole-house ventilation.

Draftstopping applied at the top of the second floor bulkhead.
Case Study: Medallion Homes

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • CASE D-4

Comfort, Durability, and Health

A radiant barrier on the roof structure 

reflects 95% of infrared radiation 

and keeps the attic up to 30 degrees 

cooler. The radiant barrier roof decking 

works with the continuous soffit and 

ridge vents, creating air flow to reduce 

attic temperature. Double-pane, lowe windows reflect infrared radiation, 

reduce energy consumption, and prevent 

carpets and furniture from fading. 

Water-based paint and flooring adhesives 

don’t emit volatile organic compounds, 

have less chemicals and odors, and lead 

to better indoor air quality for the occupants. The CocoonTM blown-in cellulose has a 

higher fire rating than fiberglass and is a natural, non-toxic pest control.

Medallion homes have fiber-cement siding, which is appropriate for hot and humid 

climates because it is resistant to rot, fungus, and termite infestation.

The Texas Master Naturalist Alamo Area Chapter presented Medallion Homes the 

Naturalist Conservation Award in recognition of Mainland Square. Mainland Square 

was one of the first neighborhoods in Texas to be certified as a Backyard Wildlife 

Habitat by the Texas Parks and Wildlife Department’s Texas Wildscapes Program.

Bottom Line

Medallion estimates that energy features on it’s Craftsman model (1,190 sq.ft.), add 

less than 1.5% to the cost of a home this size.

Medallion tracked of most of the upgrades on the Universal City pilot project and 

realized significant cost savings realized by optimizing the HVAC—going from two 

units to one and decreasing required cooling capacity dropped from 5 tons to 3.5 tons. 

Medallion decided to spend these savings on the upgraded two-speed furnace, the 

ventilation system, draftstopping for building airtightness and duct sealing measures. 

As a first-time pilot study, money was spent to fix implementation problems associated 

with remedying the initial duct layout. In all, Medallion claims that the pilot home 

project cost them an additional $300. IBACOS believes that there were enough 

remediation costs associated with the home that if the design was followed correctly 

from the start, the recommended measures would end up saving construction costs.

Front elevation of 2400 plan Pilot Home with 

synthetic stone cladding
Appendix I

Homebuyer’s Checklist

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX I-1

Below is a more detailed list of building features for those who really want to investigate their house. 

To really see how some of these measures are installed, visit houses that are under construction.

MEASURE Building 

America 

Builder

#1

Builder

#2

Builder

#3

HEATING AND COOLING EQUIPMENT

ENERGY STAR qualified air conditioning of SEER 13 or greater Yes

ENERGY STAR qualified heat pump Yes

ENERGY STAR qualified boiler Yes

ENERGY STAR qualified furnace of AFUE 90 Yes

ENERGY STAR qualified programmable thermostat Yes

Ductwork sealed with mastic (no duct tape) Yes

5% or less duct leakage found with pressure test. Yes

Duct Insulation: 

R-4 in conditioned space, R-8 in attic, R-6 in crawlspace Yes

House plans show duct layouts Yes

Ducts located in conditioned space as much as possible Yes

Ducts sized according to industry standards in Manual D Yes

Heating and cooling equipment sized according to industry 

standards in Manual J Yes

House pressure balanced with jump ducts Yes

HVAC* equipment and duct work was inspected 

and tested after installation Yes

INSULATION (take a look at a house under construction before sheetrock is installed)

Insulation installed behind tubs, landings, and other hard to 

reach places. Yes

Insulation fills entire cavities – no voids or compressed batts – 

Attic insulation level without gaps and covers entire attic floor Yes

High density batt insulation Yes

Rim joists are insulated Yes

WINDOWS (take a look at a house under construction before exterior siding is installed)

ENERGY STAR qualified windows, doors, and skylights Yes

Windows flashed to help repel water Yes

Windows rated to .35 U-factor and SHGC Yes
Appendix I: Homebuyer’s Checklist

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX I-2

MOISTURE MANAGEMENT (take a look at a house under construction before exterior siding is installed)

Ground slopes away from house Yes

Housewrap or building paper covers exterior sheathing in 

wood framed houses Yes

Roof flashing in valleys, where walls and roofs intersect, and 

at other places where water may enter the house – the more 

complex the roof, the more flashing you should see.

Yes

Overhangs for shade and to direct water away from walls Yes

AIR RETARDERS

All penetrations through exterior walls sealed Yes

Careful sealing of sheetrock or exterior sheathing Yes

Canned lights rated as airtight and for insulated ceiling (ICAT) Yes

Electrical boxes on exterior walls caulked or gasketed Yes

Holes into attic sealed Yes

Air leakage determined with house depressurization test Yes

SLAB FOUNDATION MEASURES

Radon vent pipe installed Yes

4 to 6 inch gravel base Yes

Polyethylene (plastic) vapor barrier below gravel Yes

PLUMBING

No pipes in exterior walls Yes

YOUR FEATURES FOR COMPARISON

*HVAC = heating, ventilation, and air conditioning

If you want to know more about any of these or other house features review the other chapters of the Best 

Practices guide. Other chapters are designed to help site planners, designers, site supervisors, and crafts 

people design and build efficient, comfortable, and durable homes. 
Appendix II

Energy & Housing Glossary

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX II-1

Accreditation

The process of certifying a Home Energy Rating System 

(HERS) as being compliant with the national industry 

standard operating procedures for Home Energy 

Rating System. 

AFUE Annual Fuel Utilization Efficiency (AFUE)

 Measures the amount of fuel converted to space heat in 

proportion to the amount of fuel entering the furnace. 

This is commonly expressed as a percentage. A furnace 

with an AFUE of 90 could be said to be 90% efficient. 

AFUE includes any input energy required by the pilot 

light but does not include any electrical energy for 

fans or pumps.

Air Flow Retarder

Sealants used to keep outside air and inside air out 

of the building envelope. Four common approaches 

to retarding air flow include careful sealing using the 

following building components: drywall and framing, 

plastic sheets (should not to be used in hot and humid 

climates) between drywall and framing, exterior 

sheathing, and building paper. Air flow retarders define 

the pressure boundary in a house that separates indoor 

and outdoor air.

Building Envelope

The outer shell, or the elements of a building, such 

as walls, floors, and ceilings, that enclose conditioned 

space. See also Pressure Boundary and Thermal 

Boundary.

Btu (British Thermal Unit)

A standard unit for measuring energy. One Btu is the 

amount of energy required to raise the temperature of 

one pound of water by one degree Fahrenheit from 

59 to 60. An Inches-Pounds unit.

CABO (Council of American Building Officials)

A national organization of building code officials and 

interested parties, which, through a national consensus 

process, developed, adopted and promulgated the 

national Model Energy Code (MEC). CABO has 

recently become CABO International and has taken on 

the administrative responsibility for the development 

of a uniform international building code through an 

International Code Council (ICC). 

Capacity

The rate at which a piece of equipment works. Cooling 

capacity is the amount of heat a cooling system can 

remove from the air. For air conditioners total capacity 

is the sum of latent capacity, the ability to remove 

moisture from the air, and the sensible capacity, the 

ability to reduce dry-bulb temperature. Heating system 

capacity indicates how much heat a system can provide. 

Heating and cooling capacities are rated in Btu per hour. 

Chase

A furred out enclosure designed to hold ducts, 

plumbing, electric, telephone, cable, or other linear 

components. A chase designed for ducts should be in 

conditioned space and include air flow retarders and 

thermal barriers between it and unconditioned spaces 

such as attics.

Construction Documents

The drawings (plans) and written specifications that 

describe construction requirements for a building.

COP (Coefficient of Performance)

A measure of efficiency typically applied to heat pumps. 

The COP for heat pumps is the ratio, at a given 

point in time, of net heat output to total energy input 

expressed in consistent units and under designated 

conditions. Heat pumps result in a COP greater than 

1 because the system delivers or removes more heat 

energy than it consumes. Other specific definitions of 

COP exist for refrigeration equipment. See HSPF for a 

description of a unit for seasonal efficiency.
Appendix II: Energy & Housing Glossary

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX II-2

Debt-to-Income Ratio

The ratio, expressed as a percentage, which results 

when a borrower’s total monthly payment obligations 

on long-term debt are divided by their gross monthly 

income. This is one of two ratios (housing expenseto-income ratio being the other) used by the mortgage 

industry to determine if a prospective borrower qualifies 

(meets the underwriting guidelines) for a specific 

home mortgage. Fannie Mae, Freddie Mac and FHA 

underwriting guidelines set an upper limit of 36% on 

this value for conventional loans but increase (“stretch”) 

the ratio by 2% for qualifying energy efficient houses.

Dry-Bulb Temperature

The temperature of air indicated on an ordinary 

thermometer, it does not account for the affects 

of humidity.

ECM (Energy Conservation Measure)

An individual building component or product that 

directly impacts energy use in a building and has a 

set of differentiable energy performance factors that 

can be arranged into a table or list. For example, wall 

insulation is a measure that will impact heat transfer 

to and from a building, and there is some list of wall 

measures that are differentiated by insulation R-value 

that define the possible walls that can be incorporated 

into a building.

EEM (Energy Efficient Mortgage)

Specifically, a home mortgage for which the borrower’s 

qualifying debt-to-income and housing expense-toincome ratios have been increased (“stretched”) by 

2% because the home meets or exceeds CABO’s 1992 

version of the Model Energy Code (MEC). This socalled “stretch” mortgage is nationally underwritten 

by Fannie Mae, Freddie Mac and the Federal Housing 

Administration (FHA). This term is often used 

generically to refer to any home mortgage for which the 

underwriting guidelines have been relaxed specifically 

for energy efficiency features, or for which any form of 

financing incentive is given for energy efficiency.

EER (Energy Efficiency Ratio)

A measurement of the instantaneous energy efficiency 

of cooling equipment, normally used only for electric 

air conditioning. EER is the ratio of net cooling 

capacity in Btu per hour to the total rate of electric 

input in watts, under designated conditions. The 

resulting EER value has units of Btu per Watt-hour. 

EF (Energy Factor)

A standardized measurement of the annual energy 

efficiency of water heating systems. It is the annual hot 

water energy delivered to a standard hot water load 

divided by the total annual purchased hot water energy 

input in consistent units. The resultant EF value is a 

percentage. EF is determined by a standardized US 

Department of Energy procedure. 

Energy (use)

The quantity of electricity, gas or other fuel required by 

the building equipment to satisfy the building heating, 

cooling, hot water, or other loads or any other service 

requirements (lighting, refrigeration, cooking, etc.). 

Energy Audit

A site inventory and descriptive record of features 

impacting the energy use in a building. This includes, 

but is not limited to: all building component descriptions 

(locations, areas, orientations, construction attributes 

and energy transfer characteristics); all energy using 

equipment and appliance descriptions (use, make, model, 

capacity, efficiency and fuel type) and all energy features. 

ENERGY STAR® Home

A home, certified by the US Environmental Protection 

Agency (EPA), that is at least 30% more energy 

efficient than the minimum national standard for home 

energy efficiency as specified by the 1992 MEC, or as 

defined for specific states or regions. ENERGY STAR 

is a registered trademark of the U.S. EPA. 

Envelope

See Building Envelope

Fannie Mae 

(FNMA - Federal National Mortgage Association)

A private, tax-paying corporation chartered by the U.S. 

Congress to provide financial products and services that 

increase the availability of housing for low-, moderate-, 

and middle-income Americans.

FHA (Federal Housing Administration)

A division of the Department of Housing and Urban 

Development (HUD). FHA’s main activity is the 

insurance of residential mortgage loans made by 

private lenders.
Appendix II: Energy & Housing Glossary

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX II-3

Freddie Mac 

(FHLMC - Federal Home Loan Mortgage Corporation)

A stockholder-owned organization, chartered by the 

U.S. Congress to increase the supply of mortgage funds. 

Freddie Mac purchases conventional mortgages from 

insured depository institutions and HUD-approved 

mortgage bankers.

Grade Beam

A foundation wall that is poured at or just below the grade 

of the earth, most often associated with the deepened 

perimeter concrete section in slab-on-grade foundations.

HERS (Home Energy Rating System)

A standardized system for rating the energy-efficiency 

of residential buildings. 

HERS Energy-Efficient Reference Home (EERH)

The EERH is a geometric “twin” to a home being 

evaluated for a HERS rating and is configured to 

be minimally compliant with the 1992 MEC. 

HERS Provider

An individual or organization responsible for the 

operation and management of a Home Energy 

Rating System.

HERS Rater

An individual certified to perform residential Building 

Energy Efficiency Ratings in the Class for which the 

Rater is certified. There are three classes of residential 

Rater certification: Class 3 - requiring the certified 

capability to complete Ratings based on construction 

documents; Class 2 - requiring the certified capability 

to complete Ratings based on site energy audits; 

and Class 1 - requiring the certified capability to 

complete Ratings based on site energy audits and 

performance tests.

HERS Score

A value between 0 and 100 indicating the relative 

energy efficiency of a given home as compared with the 

HERS Energy-Efficient Reference Home as specified by 

the HERS Council Guidelines. The greater the score, 

the more efficient the home. A home with zero energy 

use for the rated energy uses (heating, cooling and hot 

water only) scores 100 and the HERS Reference Home 

scores 80. Every 1-point increase in the HERS score 

amounts to a 5% increase in energy efficiency.

Housing Expense-to-Income Ratio

The ratio, expressed as a percentage, which results when 

a borrower’s total monthly housing expenses (P.I.T.I.) 

are divided by their gross monthly income. This is 

one of two ratios (debt-to-income ratio being the 

other) used by the mortgage industry to determine if a 

prospective borrower qualifies (meets the underwriting 

guidelines) for a specific home mortgage. Fannie Mae, 

Freddie Mac and FHA underwriting guidelines set an 

upper limit of 28% on this value for conventional loans 

but increase (“stretch”) the ratio by 2% for qualifying 

Energy Efficient Mortgages.

Housewrap

Any of several spun-fiber polyolefin rolled sheet goods 

for wrapping the exterior of the building envelope. 

HSPF (Heating Season Performance Factor)

A measurement of the seasonal efficiency of an electric 

heat pump using a standard heating load and outdoor 

climate profile over a standard heating season. It 

represents the total seasonal heating output in Btu 

divided by the total seasonal electric power input in 

watt-hours (Wh). Thus, the resultant value for HSPF 

has units of Btu/Wh. 

Jump Duct

A flexible, short, U-shaped duct (typically 10-inch 

diameter) that connects a room to a common space as 

a pressure balancing mechanism. Jump ducts serve the 

same function as transfer grilles. 

Load

The quantity of heat that must be added to or removed 

from the building (or the hot water tank) to satisfy 

specific levels of service, such as maintaining space 

temperature or hot water temperature at a specified 

thermostat setting (see also the definitions of energy 

and thermostat). 

Low-E

Refers to a coating for high-performance windows, the 

“e” stands for emissivity or re-radiated heat flow. The 

thin metallic oxide coating increases the U-value of 

the window by reducing heat flow from a warm(er) air 

space to a cold(er) glazing surface. Low-e coatings allow 

short-wavelength solar radiation through windows, but 

reflect back longer wavelengths of heat.
Appendix II: Energy & Housing Glossary

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX II-4

MEC (Model Energy Code)

A “model” national standard for residential energy 

efficiency. The MEC was developed through a 

national consensus process by the Council of American 

Building Officials (CABO) and is the accepted 

national minimum efficiency standard for residential 

construction. Since MEC is a model code, it does not 

have the “force of law” until it is adopted by a local code 

authority. The MEC is used as the national standard 

for determining Energy Efficient Mortgage (EEM) 

qualification, and it serves as the national “reference 

point” used by Home Energy Rating Systems (HERS) 

in the determination of energy ratings for homes. 

Mechanical Ventilation

The active process of supplying or removing air to or 

from an indoor space by powered equipment such as 

motor-driven fans and blowers, but not by devices such 

as wind-driven turbine ventilators and mechanically 

operated windows.

Performance Test

An on-site measurement of the energy performance 

of a building energy feature or an energy using device 

conducted in accordance with pre-defined testing and 

measurement protocols and analysis and computation 

methods. Such protocols and methods may be defined 

by national consensus standards like those of the 

American Society of Heating, Refrigerating and Air 

Conditioning Engineers (ASHRAE) and the American 

Society for Test and Measurement (ASTM).

P.I.T.I.

An abbreviation which stands for principal, interest, 

taxes, and insurance. These generally represent a 

borrower’s total monthly payment obligations on a 

home loan. The taxes and insurance portion are often 

paid monthly to an impound or escrow account and 

may be adjusted annually to reflect changes in the 

cost of each.

Pressure Boundary

The point in a building at which inside air and outside 

air are separated. If a building were a balloon, the 

rubber skin would form the pressure boundary. Where 

inside and outside air freely mingle there is no 

pressure boundary. 

Pressurization Test

A procedure in which a fan is used to place a house, 

duct system, or other container, under positive or 

negative air pressure in order to calculate air leakage. 

RESNET (Residential Energy Services Network)

The national association of energy rating providers. 

Rated Home

A specific residence that is evaluated by an energy rating. 

R-Value

Measures a material’s ability to slow down or resist the 

transfer of heat energy, also called thermal resistance. 

The greater the R-value, the better the resistance, the 

better the insulation. R-values are the reciprocal of 

U-values. See U-values for more information.

Sealed Combustion

Sealed combustion means that a combustion appliance, 

such as a furnace, water heater, or fireplace, acquires all 

air for combustion though a dedicated sealed passage 

from the outside; combustion occurs in a sealed 

combustion chamber, and all combustion products 

are vented to the outside through a separate dedicated 

sealed vent. 

SEER (Seasonal Energy Efficiency Ratio)

A measurement similar to HSPF except that it measures 

the seasonal cooling efficiency of an electric air 

conditioner or heat pump using a standard cooling load 

and outdoor climate profile over a standard cooling 

season. It represents the total seasonal cooling output in 

Btu divided by the total seasonal electric input in watthours (Wh). The SEER value are units of Btu/Wh. 

Semi-Permeable

The term vapor semi-permeable describes a material 

with a water vapor permeance between 1 and 10 

Perms. Water vapor can pass through a semi-permeable 

material but at a slow rate.

Shading Coefficient (SC)

The ratio of the total solar heat admittance through 

a given glazing product relative to the solar heat 

admittance of “double-strength, clear glass at normal 

solar incidence (i.e. perpendicular to the glazing surface). 
Appendix II: Energy & Housing Glossary

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX II-5

Solar Heat Gain Coefficient (SHGC)

SHGC measures how well a window blocks heat caused 

by sunlight. The lower the SHGC rating the less solar 

heat the window transmits. This rating is expressed as 

a fraction between 0 and 1. The number is the ratio of 

a window’s solar heat admittance compared to the total 

solar heat available on the exterior window surface at 

normal solar incidence (i.e. perpendicular to the 

glazing surface). 

Sone

A sound rating. Fans rated 1.5 sones and below are 

considered very quiet.

Supply ducts

The ducts in a forced air heating or cooling system that 

supply heated or cooled air from the or air conditioner 

to conditioned spaces.

Thermal Boundary

The border between conditioned and unconditioned 

space where insulation should be placed. 

Thermostat

A control device that measures the temperature of the 

air in a home or the water in a hot water tank and 

activates heating or cooling equipment to cause the air 

or water temperature to remain at a pre-specified value, 

normally called the set point temperature. 

Ton(s) of Refrigeration

Units used to characterize the cooling capacity of air 

conditioning equipment. One ton equals 12,000 Btu/h. 

U-Value

Measures the speed at which heat flows or conducts 

through a building assembly (wall, floor, ceiling, etc.). 

The smaller the u-value the more energy efficient an 

assembly and the slower the heat transfer. Window 

performance labels include U-values (calling them Ufactors) to help in comparing across window products. 

Ventilation

The controlled movement of air into and out of a house.

W (watt)

One of two (Btu/h is the other) standard units of 

measure (SI –or metric- System) for the rate at which 

energy is consumed by equipment or the rate at which 

energy moves from one location to another. It is also 

the standard unit of measure for electrical power. 

Wet-Bulb Temperature

A measure of combined heat and humidity. At the same 

temperature, air with less relative humidity has a lower 

wet bulb temperature. See Dry-Bulb Temperature.

Wind-Washing

Air movement due to increased pressure differences that 

occur at the outside corners and roof eaves of buildings. 

Wind-washing can have significant impact on thermal 

and moisture movement and hence thermal and 

moisture performance of exterior wall assemblies.

Xeriscaping

Landscaping that minimizes outdoor water use while 

maintaining soil integrity and building aesthetics. 

Typically includes emphasis on native plantings, 

mulching, and no or limited drip/subsurface irrigation.

Zero Energy House

Any house that over time, averages out to net zero 

energy consumption. A zero energy home may supply 

more energy than it needs during peak demand, 

typically using one or more solar energy strategies, 

energy storage and/or net metering. 
Appendix II: Energy & Housing Glossary

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX II-6

Sources & Additional Information

• American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE). 1986. 

Terminology of Heating Ventilation Air Conditioning and Refrigeration. Atlanta, GA. 

• Building News. 2001. Construction Dictionary. BNi Publications, Los Angeles, CA.

• Florida Solar Energy Center (FSEC). Energy-Efficiency Economics Terms and Definitions available 

on the web at www.fsec.ucf.edu/bldg/fyh/ratings/e_terms.htm

• Lstiburek, Joseph. 2002. Builder’s Guide Hot and Humid Climates. Energy & Environmental Building 

Association. Minneapolis, MN www.eeba.org

• Home Energy Magazine. 1997. “No-Regrets Remodeling: Creating a Comfortable, Healthy Home That 

Saves Energy.” Energy Auditor & Retrofitter, Inc. Berkeley, CA.
Appendix III

Code Official Tear-Outs

Building America Best Practices Series: Volume 1 – Builders and Buyers Handbook for 

Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate Version 1, 10/2004 • APPENDIX III - 1

The following tear-out sheets, contained in this chapter’s addendum, 

may help in explaining some energy-efficient design techniques to 

code officials unaware of them. Each topic “sheet” is designed to stand 

alone and includes a description of the technique and why it is useful, 

a discussion of the relevant code sections that permit the technique, 

and guidance on what the official should look for in plan reviews 

and inspections.

• Single Top Plates

• No Header in Non-Bearing Walls

• Floor Joists Spaced at 24” O.C.

• Studs Spaced at 24” O.C.

• Open Spaces as Return-Air Options

• Details for Mechanically-Vented Crawl Spaces

• Ventilation Requirements for Condensing Clothes Dryers

• Drywall Clips

• Rigid Board Insulation Installed 

as Draft Stop in Attic Kneewall
Single Top Plates

Standard practice for exterior and interior wall framing is to use a double top

plate to connect wall segments and to support framing above the plates. A single

top plate is allowed under the International Residential Code but is an uncommon

construction practice.

Eliminating unnecessary wood framing within walls can increase the thermal

efficiency of the wall system. Less framing allows more insulation to be installed

and also eliminates hot and cold spots within the wall system. Eliminating wood

framing can also reduce drywall cracking caused by the movement of wood

within the walls. Using a single top plate, instead of a traditional double top plate,

is allowed by code in some wood frame walls.

The single top plates must be

adequately tied at joints,

corners and intersecting walls

by at least a 3” x 6” - 0.036-

inch thick galvanized steel

plate that is nailed to each wall

or wall segment by six 8d nails

on each side. Rafters or joists

must be within 1 inch of center

over the studs. The top plate

may be omitted over lintels that

are adequately tied to adjacent

wall sections with steel plates.

Interior nonbearing walls may be 2” x 3” inch studs spaced 24 inches (610 mm)

on center or, if not part of a braced wall line, 2” x 4” inch flat studs 16 inches on

center. Interior nonbearing walls must be capped with at least a single top plate

and fireblocked.

Plan Review

1. Verify that the wall framing details call out a single top plate and also

specify the 3” x 6” – 0.036-inch thick galvanized steel plate to be installed

Single Top Plate

Rafters / Roof Trusses

Within 1” of stud spacing

Floor joists within

1” of stud spacing

Studs spaced at 24” o.c.

Corners and wall segments

connected using 3” x 6” galvanized

metal plate using 6-8d nails on

each side.

Single Top Plate

Rafters / Roof Trusses

Within 1” of stud spacing

Floor joists within

1” of stud spacing

Studs spaced at 24” o.c.

Corners and wall segments

connected using 3” x 6” galvanized

metal plate using 6-8d nails on

each side.

Issue

Background / Description

Plan Review / Inspection Guidance:
at each corner and wall segment. Also verify the nailing required under

IRC Section 602.3.2, Exception is specified on the building plans.

2. Verify that the spacing for the roof framing is identical to that of the wall

framing. For example the roof framing must be spaced at 24” on center if

the wall framing is also spaced at 24” on center. The rafter / roof trusses

must be within 1” of being directly above the wall studs.

3. If the wall system supports a floor, verify that the wall floor joist spacing is

identical to the wall stud spacing.

Field Inspection

1. Verify that the top plate is fastened to the studs per IRC Table R602.3(1).

2. Verify that a 3” x 6” – 0.036-inch thick galvanized steel plate is installed at

each corner and wall segment and that six 8d nails are used to attach

each side of the plate to the corner or wall segment.

3. Verify that the rafters or trusses used in the roof framing are within one

inch of the center of each of the studs below.

4. Verify that the floor joists supported by the studs are within one inch of the

center of the studs below.

IRC 2000 and 2003, in section R602.3.2 Top Plate

Exception: A single top plate may be installed in stud walls, provided the plate is

adequately tied at joints, corners and intersecting walls by a minimum 3-inch-by-6-inch by

a 0.036-inch-thick (76 mm by 152 mm by 0.914 mm) galvanized steel plate that is nailed

to each wall or segment of wall by six 8d nails on each side, provided the rafters or joists

are centered over the studs with a tolerance of no more than 1 inch (25.4 mm). The top

plate may be omitted over lintels that are adequately tied to adjacent wall sections with

steel plates or equivalent as previously described.

IRC 2000 and 2003, in Figure 602.3(2)

The figure label states “single or double top plate”.

IRC 2000 and 2003, in section R602.5 Interior Nonbearing Walls

Interior nonbearing walls shall be permitted to be constructed with 2-inch-by-3-inch (51

mm by 76 mm) studs spaced 24 inches (610 mm) on center or, when not part of a braced

wall line, 2-inch-by-4-inc h (51 mm by 102 mm) flat studs spaced at 16 inches (406 mm)

on center. Interior nonbearing walls shall be capped with at least a single top plate.

Interior nonbearing walls shall be fireblocked in accordance with Section R602.8.

Code Citations
No Headers in Nonbearing Walls

The use of header stock over windows and doors in nonbearing walls is typical

construction practice throughout the industry. But a single 2” x 4” is allowed to

be used as a header in nonload bearing wall systems. This practice is unfamiliar

to many in the enforcement and building industry.

Eliminating unnecessary wood framing within walls can increase the energy

efficiency of the wall. Less framing allows more insulation to be installed and

also eliminates hot and cold spots within the wall. Eliminating wood framing can

also reduce drywall cracking caused by the movement of wood within the walls.

A single flat 2x4 may be used as a header in exterior, or interior, non-load

bearing walls. The maximum opening may not exceed 8 feet. The vertical

distance to the parallel surface above must be not more than 24 inches. No

cripples or blocking are required above the header. On exterior walls, cavities

above the headers must be insulated.

Issue

Background / Description
Maximum 2’ Above Header

Maximum 8’ Span

Insulate Headers
Plan Review

1. Verify that the framing details call out no headers only for non-bearing

interior or exterior walls.

2. Verify the horizontal span for each rough window and door opening is no

greater than 8 feet.

3. Verify that the header height between the header and the next parallel

framing member above the header is not greater than 2 feet. The next

vertical parallel framing member will typically be the top plate.

Field Inspection

Framing Inspection:

1. Verify that the horizontal rough opening framed out in the wall

assembly matches, or is less than, that called out on the approved

building plans.

2. Verify that the distance between the header and the next parallel

framing member (typically the top plate) is no greater than 24 inches.

Insulation Inspection

Verify that the framing cavity above the header is insulated to the required

insulation R-value called out on the approved plans or documentation.

IRC 2000 and 2003, Section 602.7.2

Nonbearing walls. Load-bearing headers are not required in interior or exterior

nonbearing walls. A single flat 2-inch-by-4-inch (51 mm by 102 mm) member may be

used as a header in interior or exterior nonbearing walls for openings up to 8 feet (2438

mm) in width if the vertical distance to the parallel nailing surface above is not more than

24 inches (610 mm). For such nonbearing headers, no cripples or blocking are required

above the header.

IRC 2000 and 2003 Table R702.3.5 Minimum Thickness & Application of

Gypsum Board

Allows the use of 24” on center framing for fastening gypsum board with either fasters or

adhesive _” thickness or greater.

Plan Review / Inspection Guidance

Code Citations
IRC 2000 and 2003 Section R703 Exterior Covering

Structural sheathing and siding requirements are based on Table R703.4. Note that

footnote “a” specifies that the table is based on 16” o.c. and that studs spaced 24”o.c.

siding shall be applied to sheathing approved for that spacing.
Header Hangers in Bearing Walls

Headers for windows and doors are typically supported by cripples or jack studs.

These studs can be eliminated using header hangers, as allowed under the

International Residential Code.

Eliminating unnecessary wood framing within walls can increase the thermal

efficiency of the wall system. Less framing allows more insulation to be installed

and also eliminates hot and cold spots within the wall system. Eliminating wood

framing can also reduce drywall cracking caused by the movement of wood

within the walls.

Jack studs or trimmers that support headers around windows can be eliminated

through the use of an approved framing anchor (“header hanger”) attached to the

full-height wall stud and to the header (see Figure). 2000 IRC Table R502.5(1),

Footnote “d” allows for the use of header hangers based on the following

parameters:

• Ground Snow Load

• Building Width

• Number of Floors and Roof assemblies supported

• Size of the header material

• Span of the header

Wood structural panel box headers are limited to a span of no greater than 4 feet

if using a header hanger.

Issue

Background / Description
Plan Review

1. Verify the number of floors and/or roof ceiling assemblies that is being

supported by the header per Table R502.5(1).

2. Verify that the building width perpendicular to the ridge is not greater than

that shown in Table R502.5(1).

3. Verify that the span of each window opening, where a header hanger is

proposed, is not greater than the value shown in Table R502.5(1).

4. Verify that the proposed header hanger to be used in the project has an

ICC Evaluation Services report.

Field Inspection

1. Verify that the span of the opening is not greater than that shown on the

building plans.

2. Verify that the header material is #2 grade lumber or better.

3. Verify that the header hanger is properly nailed per the manufacturer’s

instructions.

Plan Review / Inspection Guidance
IRC 2000 and 2003, Table R502.5(1) Girder Spans and Header Spans for

Exterior Bearing Walls Footnote “d”

d. NJ – Number of jack studs required to support each end. Where the number of

required jack studs equals one, the header are permitted to be supported by an

approved framing anchor attached to the full-height wall stud and to the header.

Code Citations
Floor Joists Spaced at 24” O.C.

Floor joists must be spaced at 24” on center if used as part of an advanced

framing strategy where the wall assemblies us a single top plate. This will allow

the load to be transferred directly to the studs or foundation below.

Floor joists must be spaced at 24 inches on center if load bearing wood studs are

spaced at 24 inches on center and a single top plate is used for the wall system.

Plan Review

1. If dimensional lumber is used for the floor joists, verify that the floor joist

spans are consistent with Table R502.3.1(1) for 24” on center spacing for

the following:

• Dead Load,

• Maximum floor joist span,

• Dimension of lumber, and

• Specie and grade of lumber

24” o.c.

Prefabricated Wood

I-Joists

24” o.c.

Wood Studs

Single Top Plate 24” o.c.

Prefabricated Wood

I-Joists

24” o.c.

Wood Studs

Single Top Plate

24” o.c.

Wood Studs

Single Top Pla

24” o.c.

Dimension Lumbe

Issue

Background / Description

Plan Review / Inspection Guidance
2. If prefabricated wood I-joists are used for the floor joist, verify that the floor

joist spacing is consistent with the manufacturer’s specifications for the

following:

• Dead load

• Maximum floor joist span

3. Verify that the floor sheathing selected for the subfloor conforms to the

requirements per Table R503.1, R503.2.1.1(1) or R503.2.1.1(2).

Field Inspection

1. Verify that the floor joists are consistent with the floor joists

called out on the approved building plans.

2. Verify that the subfloor installed on site is consistent with the subfloor type

and thickness called for on the building plans.

IRC 2000 and 2003, Section R602.3.3 Bearing Studs

Where joists, trusses or rafters are spaced more than 16 inches on center and the

bearing studs below are space 24 inches on center, such members shall bear within 5

inches of the studs beneath.

IRC 2000 and 2003, Section 502.3 Allowable Joist Spans

2000 and 2003 IRC Table R502.3.1(1) Floor Joist Spans for Common Lumber Species

(Residential sleeping areas)

2000 and 2003 IRC Table R502.3.1(2) Floor Joist Spans for Common Lumber Species

(Residential living areas)

For other grades and species and for other loading conditions, refer to AF&PA span

Tables for Joists and Rafters.

IRC 2000 and 2003, Section R502.3.1 Sleeping Areas and Attic Joists

Table R502.3.1(1) shall be utilized to determine the maximum allowable span of

floor joists that support sleeping areas and attics that are accessed by means of

a fixed stairway provided that the live load does not exceed 30 psf and the

design dead load does not exceed 10psf. The allowable span for ceiling joists

that support attics utilized for limited storage or no storage shall be determined in

accordance with Section R802.4.

IRC 2000 and 2003, Section R502.3.2 Other floor joists

Table R502.3.1(2) shall be utilized to determine the maximum allowable span of floor

joists that support all areas of the building, other than sleeping and attics, provided that

the design live load does not exceed 40 psf and the design dead does not exceed 10 psf.

Code Citations
IRC 2000 and 2003, Section R602.3.2 Top Plate

Exception: A single top plate may be installed in stud walls, provided the plate is

adequately tied at joints, corners and intersecting walls by a minimum 3-inch-by-6-inch by

a 0.036-inch-thick (76 mm by 152 mm by 0.914 mm) galvanized steel plate that is nailed

to each wall or segment of wall by six 8d nails on each side, provided the rafters or joists

are centered over the studs with a tolerance of no more than 1 inch (25.4 mm). The top

plate may be omitted over lintels that are adequately tied to adjacent wall sections with

steel plates or equivalent as previously described.
Studs Spaced at 24” o.c.

Walls are typically framed using framing spaced at 16” on center. Framing

spacing can be moved to 24” on center, as allowed by the International

Residential Code and the jurisdiction.

Background/Description

Eliminating unnecessary wood framing within walls can increase the thermal

efficiency of the wall system. Less framing allows more insulation to be installed

and also eliminates hot and cold spots within the wall system. Eliminating wood

framing can also reduce drywall cracking caused by the movement of wood

within the walls.

Spacing stud framing at 24 inches on center verses 16 inches on center reduces

the number of framing members in exterior wall systems. This will allow more

insulation to be placed in the wall system compared to standard 16 inch on

center construction.

The 2000 and 2003 IRC allow for 2 x 4 and 2 x 6 studs to be spaced at 24 inches

on center under certain circumstances (see Code References Allowing This

Installation).

Plan Review

1. Verify the stud size, spacing and height (<10 ft) is consistent with the

maximum stud spacing in Table R602.3(5) for bearing walls. Verify

that the stud grade called out on the plans is No. 3, standard or stud

grade lumber.

2. Verify that stud size, spacing and height (> 10ft) is consistent with

Table R602.3.1. Verify that the framing design in Seismic Category D

meets the requirements of footnote “a”, “b” and “c” of Table R602.3(5).

Verify that the stud grade called out on the plans in Seismic Category

D is consistent with footnote “c”.

Issue

Plan Review / Inspection Guidance
3. Verify that sheathing is called out on plans and is consistent with

footnote “j” of Table R703.4 for 24” stud spacing.

Field Inspection

1. Compare the stud grade with what is called out on the framing details

on the approved building plans for studs < 10ft and studs > 10ft.

2. Verify that the sheathing type and thickness installed on site is

consistent with that called out on the approved building plans.

IRC 2000, Section R602.3.1

In bearing walls, studs that are not more than 10 feet in length shall be spaced not more

than is specified in Table R602.3(5). In bearing walls, studs that are more than 10 feet in

height shall be spaced not more than specified in Table R602.3.1.

IRC 2003, Section R602.3.1.

The size, height and spacing of studs shall be in accordance with Table R602.3(5).

IRC 2000 and 2003, Table R602.3.1

Stud Spacing Based on Length of Wood in Seismic Design Categories A, B, C and D

Exposed to Wind

2 x 4 framing between >10 feet and less than 12 feet in length can support up a roof only

if spaced at 24 inches on center.

2 x 6 framing can support two floors and a roof up to a length of 14 feet spaced at 24

inches on center without a design required.

IRC 2000 and 2003, Table R703.4 Weather-Resistant Siding Attachment and

Minimum Thickness

Provides requirements by sheathing and siding material for framing spaced 24 inches on

center.

Code Citations
Open Spaces as Return-Air Options

Stud cavities and floor joist spaces are often used to return air to the

HVAC system’s air-handler, and are specifically allowed in the Icodes. Field testing shows that these return systems are often

extremely leaky. Leaks within areas that include combustion

appliances break the code and present potential health risks. Open

spaces in the building are often effective and inexpensive; for

example, incorporating hallways as a part of a return-air system.

Homes with basements often use wall stud and floor joist spaces as

return-air cavities. Extensive testing indicates that duct leakage in

these homes is very high unless ducts have been pressure tested

and sealed under some beyond code program (utility, state or local)

that tests for duct tightness. In one random sample of 40 homes

during 2000, over 60% of the leaks were located in the return-air

ducts. In one-third of those homes, return-air leaks connected to the

basement could create enough negative pressure that exhaust gases

were at risk of being back-drafted down water heater flues.

Some jurisdictions want every bedroom have a return-air duct directly back to the

HVAC cabinet. Yet field measurements in typical homes indicate that secondfloor return-air ducts relying on building cavities for air transport are often so

leaky that they returned little air to the HVAC blower. By code building cavities

used for return air can only convey air from one floor level back to the HVAC

blower (2000 and 2003 IRC M1601.1.1 #7).

Issue

Background / Description
As an inexpensive and effective alternative to seal ducts, the code specifically

allows return air by “connecting rooms by permanent openings.” For example,

hallways can be part of the return air path.

Two generic approaches are identified that fit the code.

Strategy #1, for single-story and multi-story homes:

1. Use either hard ducts or flex ducts for short, centralized returns that only

pull air from central hallways and living zones. (Flex ducts are easy to

seal tightly but are also vulnerable to flow restrictions.)

2. Any of the following is acceptable for pressure relief in bedrooms and

dens with operable doors:

a. A pair of offset transfer-air grilles in room walls that connect to

hallways or other open spaces directly linked to the central

return.

b. Short “jump ducts” (typically located in ceilings) that allow room

air to flow back to hallways.

c. Any method of pressure balancing that, during operation of the

HVAC blower, creates no more than a 2.5-pascal pressure

difference across closed doors (amendment to the Florida code

in 2003). This may require a pressure test.

Strategy #2, more suitable for ranches:

One HVAC ductwork concept incorporates a dropped ceiling. In a hallway

ceiling that has already been finished with drywall, ductwork and underframing is installed to create a long dropped ceiling, typically providing a 7-

foot ceiling height the length of the hallway. The supply plenum and miniruns are suspended within the cavity; the rest of the dropped ceiling cavity

carries return air from individual rooms back to the HVAC air-handler.

(For more details, see “For More Information.”)

The plan review guidance for Strategy #1 assumes that mechanical plans

have been submitted for permit. If no mechanical plan is submitted

compliance will need to be determined in the field.

1. Verify that the mechanical plan shows the location of the return and supply

duct system and the proposed cfm for each register.

2. Verify that the location of the jump ducts, offset transfer grills or pressure

balancing strategy is shown on the plan.

Plan Review / Inspection Guidance
3. Verify that the total unobstructed area for each transfer grille is specified

on the plans. The grille area should be based on the total supply cfm for

the room.

4. Verify that the return duct(s) back to the system is sized per

manufacturers specification. Verify that the return duct locations are in

centralized hallways or living zones and not in a closet, bathroom, toilet

room, kitchen, garage, mechanical room, furnace room, other dwelling

unit, or a room containing a fuel burning appliance that draws its air from

that exhausts air into that room..(IRC 2000 and 20003 Section M1602.3).

5. Require a construction detail to show the proposed jump ducts, offset

transfer grills or pressure balancing strategy.

Plan Review for Strategy #2 assumes that mechanical plans have been

submitted for permit. If no mechanical plan is submitted compliance will need

to be determined in the field.

1. Verify that a mechanical plan has been submitted that shows the location

of the return and supply duct system and that proposed cfm for each

register.

2. Verify that the total unobstructed area for each transfer grille is specified

on the plans. The grille area should be based on the total supply cfm for

the room.

3. Require a construction detail to show the dropped ceiling detail and how

the supply duct will be suspended and supported in the dropped ceiling

space.

Field Inspection

1. If mechanical plans have been submitted verify that that the installed

system matches the system shown on the approved building plans.

2. If mechanical plans have not been submitted verify the following in the

field:

a. For Strategy #1, verify that a transfer grill or jump duct is installed

for each sleeping room. Also, verify that centralized returns are

located in a hallway or living space.

b. For jump ducts verify that the duct work is sealed.

c. For Strategy #2, verify that the dropped ceiling space was framed

after the sheetrock was installed and taped in the hallway. Also,

verify that the sheetrock that forms the sides of the dropped return

air cavity is sealed to the top plate.

d. Verify that the supply duct is properly sealed and supported per

IRC Section M1601.3.

Code Citations
IRC 2003, Section M1601 Duct Construction, M1601.1.1 Above Ground Duct

Systems

Item #7

Stud wall cavities and the spaces between solid floor joists to be utilized as air plenums shall

comply with the following conditions:

7.3 Stud wall cavities shall not convey air from more than one floor level.

7.4 Stud wall cavities and joist space plenums shall be isolated from adjacent

concealed spaces by tight-fitting fire blocking in accordance with Section R602.8

IRC 2000 and 2003, Section M1601.3.1

Joints of duct systems shall be made substantially airtight by means of tapes, mastics,

gasketing or other approved closure systems...

IRC 2000 and 2003, Section M1602.2 Prohibited Sources

Prohibited sources, allows for permanent openings between rooms in order to connect

spaces together to meet a return-air location requirement:

Item 4 prohibits return air sources as follows “A closet, bathroom, toilet room, kitchen,

garage, mechanical room, furnace room or other dwelling unit” Item 5 prohibits “A room

or space containing a fuel-burning appliance where such a room serves as the sole

source of return air.”.

For more information:

--Builder’s Guide: Cold Climates, Joe Lstiburek (Energy & Environmental Building

Association, 2001) p. 179; available from www.eeba.org

--“Design and Construction of Interior Duct Systems,” Florida Solar Energy Center

(FSEC-PF-365-01), www.fsec.ucf.edu
Details for Mechanically-Vented Crawl Spaces

Codes allow conditioned crawl spaces with mechanical ventilation

instead of crawl spaces with passive vents to the outdoors. However,

code officials and builders are often uncertain about the design

details.

Traditional crawl space designs include passive foundation-wall vents that are

supposed to let moisture and contaminants escape outside. Yet field research

shows that venting may make these potential problems worse. Eliminating crawl

space vents and drawing house air in to condition the crawl space reduces

moisture problems and can increase energy efficiency.

The IRC specifically allows crawl space designs with an exhaust ventilation

system instead of fixed ventilation openings through the foundation walls. To

comply, a mechanically-vented crawl space design must have a continuously

sealed ground cover, no fixed ventilation openings to the outdoors, and must be

supplied with a continuously operating exhaust fan.

Sizing the fan. Two design options:

A. Size to the code minimum: Eliminate the foundation vents when

continuously operated mechanical ventilation is provided at a rate of 1.0 cfm for

each 50 square feet of under-floor space (e.g., 20 cfm per 1000 ft2

) (Section

R408.2, Exception 4).

B. Size to crawl-space volume: Size for one air-change per hour--the

assumed ventilation rate for crawl spaces with passive vents in foundation walls.

For example, a 1000 ft2 crawl space with 3.5 feet between ground and floor deck,

a fan should exhaust 58 cfm.

Type of fan: Code does not specify details about fans used in crawl spaces.

One possibility is to follow the Colorado amendments to the IRC. Require a fan

rated for 44,000 hours (5 years) of continuous operation with flex connections or

other installation detailing to reduce vibration and noise associated with the fan.

The fan must be connected to a trouble light or an alarm to signal occupants

when the fan fails.

Issue

Background / Description
Supply air for the exhaust fan: Transfer-air openings, one per 250 ft2 of crawl

space floor area, are installed in the decking between the crawl space and

conditioned rooms above. A continuously operating exhaust fan pulls house air

down through these openings. Airflow through the transfer openings is restricted

(e.g., through a capped “boot” that has holes drilled in the cap) per Table.

Amount of air required Minimum hole size Maximum hole size

0 – 10 CFM 1.5 in2 min. 2.4 in2 max.

11-15 CFM 2.4 in2 min. 3.6 in2 max.

16 – 20 CFM 3.6 in2 min. 4.4 in2 max.

Pressure balance: the crawl-space exhaust fan, typically 30-60 cfm, will exert

slight negative pressure on the house above. The resulting negative pressure

will roughly equal that from a bathroom fan, but will be considerably less than the

pressure generated by dryers and kitchen exhaust fans. The recommended

design specification: when all exhaust appliances and any forced-air HVAC

system operate simultaneously, any zone with an atmospherically-vented gas

appliance should experience less than 3 pascals of negative pressure.

1. Removal of debris: the under-floor grade is clean of all construction

materials, vegetation and (non-soil) organic material (2000 and 2003 IRC

R408.4).

2. Crawl space wall insulation: installed in accordance with the IECC or IRC

specifications.

3. Ground cover: “continuous vapor retarder” would be sheet material with

less than 1.0 permeance (e.g., polyethylene film) that is sealed at joints as

well as to the foundation wall plus to all piers and other penetrations; or a

concrete slab.

4. Fan, when using Exception 4: sized to provide a minimum of 1 cfm per 50

ft2 of under-floor space.

5. Supply-air pathways: Look for pathways allowing house air to be drawn,

under slight negative pressure, into the crawl space (e.g., one transfer-air

grille per 250 ft2 of crawl space floor area). Calculations should specify

transfer air sizing.

IRC 2000 and 2003, Section R408 Under-Floor Space

R408.1 Ventilation. The under-floor space...shall be provided with ventilation openings

through foundation walls or exterior walls.

Exceptions: #4. Ventilation openings are not required where continuously operated

mechanical ventilation is provided at a rate of 1.0 cfm (1.02 L/s) for each 50 square feet

Plan Review / Inspection Guidance:

Code Citations
(10m3

) of under-floor space floor area and ground surface is covered with an approved

vapor retarder material.

IMC 2000 and 2003, Section 403 Mechanical Ventilation

403.1 Ventilation system. ...The system shall not be prohibited from producing negative

or positive pressure.

For additional information:

--“The Case for Conditioned, Unvented Crawl Spaces,” Peter Yost and Ann

Edminster, Building Safety Journal, May 2003

--“Recommended Moisture Control Amendments to the IRC,” Colorado ICC

Chapter (Sept 2003 draft); and “Guidelines for Design and Construction of New

Homes with Below-Grade Underfloor Spaces,” Moisture Management Task

Force, September 2003 draft (www.e-star.com)
Ventilation Requirements for Condensing Clothes

Dryers

Conventional dryers require ductwork to exhaust water vapor from

the appliance during operation. That exhaust can contribute to

negative pressure in the home, depending on location. Some

condensing dryers, relatively new products to the U.S. marketplace,

don’t require any ducted exhaust.

A fully-loaded conventional clothes dryer exhausts several pounds of water, in its

vapor form, during a typical drying cycle. That water vapor is exhausted to the

outdoors.

By contrast, some condensing dryers are designed to condense that water into

liquid. These tend to increase energy efficiency. Some dryers draw in room air to

cool the interior air and condense the water into a condensate holder. Some

appliances use small blowers to circulate air across a heat-exchanger inside the

dryer. Others use an internal water-cooling system to condense the water vapor.

Whatever the design particular, the condensate is either pumped away to the

drain or is emptied by hand at the end of the drying cycle. Some condensing

dryers are actually combo washer/dryer appliances. Common in Europe for

years, these appliances are becoming more widely used in the U.S.

Condensing dryers can be useful in situations where the laundry room is located

a significant distance from an exterior wall that it can vent to, thereby avoiding a

long dryer vent run and possible moisture condensation problems on that run.

Issue

Background / Description

Plan Review / Inspection Guidance
Plan Review

Verify that the building plans specify a condensing (ductless) dryer or

ventless combo washer/dryer to be installed.

Verify that the proper drainage has been shown on the plumbing plans for

condensing dryers using a pump to remove condensate from the dryer.

Field Inspection

Framing inspection

Verify that the proper drainage has been provided for the condensing

dryer if a pump is used to remove the condensate.

Verify that the drainage that is provided is per manufacturers

specifications.

IRC 2003, Section M1501 Clothes Dryer Exhaust

M1501.1 General. Dryer exhaust systems shall be independent of all other systems,

shall convey the moisture to the outdoors and shall terminate on the outside of the

building.

Exception: This section shall not apply to listed and labeled condensing

(ductless) clothes dryers.

IRC 2003 Section P3001 – General.

The provisions of this chapter shall govern the materials, design, construction and

installation of sanitary draining systems. Plumbing materials shall conform to the

requirements of this chapter. The drainage waste and vent (DWV) system shall consist

of all piping for conveying wastes from plumbing fixtures, appliances and appurtenances,

including fixture traps; above grade drainage piping; below- grade drains within the

building (building drain); below-and above-grade venting systems; and piping to the

public sewer or private septic system.

IMC 2003, Section 504 Clothes Dryer Exhaust, Section 504.1 Installation

Clothes dryers shall be exhausted in accordance with the manufacturer’s instructions.

Exception: This section shall not apply to listed and labeled condensing (ductless)

clothes dryers.

For additional information:

--Web search under “condensing clothes dryers” will generate product lists and detailed

product-specific functional descriptions and product specifications.

Code Citations
Drywall Clips

Many jurisdictions are not familiar with using drywall clips for wall gypboard.

Metal or plastic drywall clips can be used to replace a third stud at a corner, at a partition

intersection backing stud, or in the ceiling to replace a nailer. The reduced attachment

(wood to drywall) resulting from the use of dry wall clips allows small movements

without drywall cracking and nail pops. Small movements are normal as wood responds

to changes in temperature and moisture content over time.

Nails and screws are not used with drywall clips.

Two-stud corners and drywall clips are often used in combination with airtight drywall,

where the drywall and well-sealed gypboard seams provide an effective interior air

barrier.

Issue

Background / Description

Plan Review / Inspection Guidance
IRC 2000 and 2003, Section R602.3 Design and Construction

Exterior walls of wood-frame construction shall be designed and constructed in

accordance with the provisions of this chapter and Figures R602.3(1) and R602.3(2) or in

accordance with AF&PA’s NDS. Components of exterior walls shall be fastened in

accordance with Table R602.3(1) through R602.3(4).

IRC 2000 and 2003, Figure R602.3(2)

Note: A third stud and/or partition intersection backing studs shall be permitted to be omitted

through the use of wood back-up cleats, metal drywall clips or other approved devices that will

serve as adequate backing for the facing materials.

Code Citations
Rigid Board Insulation Installed as Draft Stop in Attic

Kneewall

Rigid board insulation (foam plastic) is an effective draft stop and also increases

the R-value of the attic kneewall if installed on the attic side of the kneewall,

replacing the need for separate draft stop and insulation products. The IRC

requires foam plastic insulation to be protected against ignition by using

fiberglass batt insulation, gypsum board or other products that meet the flame

and smoke density requirements. Foam plastic products rated for flame and

smoke density can be installed without such a protective covering.

Insulating attic kneewalls between a conditioned space with vaulted ceilings and

the attic is important to reduce energy loss through the wall, especially in the

summer months. To be effective, the insulation installed in the kneewalls must

be supported so that it stays in contact with the gypsum board, and protected

against air moving through the insulation.

Foam plastic insulation can be installed on the attic side of the attic kneewall (see

Figure) to both act as a draft stop between the conditioned house and the

unconditioned attic and to increase the insulation R-value of the attic kneewall.

Installing such an insulating backing in the kneewall supports the fiberglass batt

insulation between framing members, replaces an air barrier, and adds insulating

value to the attic kneewall.

Issue

Background / Description
Plan Review:

1. Verify that plastic insulation called out on the construction detail meets the

ASTM E 84 requirements for flame spread and smoke development.

Require manufacturer’s literature or an ICC Evaluation Service report.

2. Verify that the insulation R-value of the foam plastic insulation called out

on the building plans meets or exceeds the R-value requirements called

for on the energy code compliance documentation (only if credit has been

taken for the foam plastic insulation).

Field Inspection:

1. Verify that the foam plastic insulation installed in the field is consistent with

that called out on the building plans.

2. Verify that the insulation R-value specified on the insulation meets or

exceeds the R-value called out on the plans or documentation.

3. Verify that that sealant has been installed around the edges of the

insulation and that any holes or penetrations in the foam plastic insulation

are sealed.

IRC 2000, Section R318.2.3 and IRC 2003, Section R314.2.3

Within attics and crawlspaces, where entry is made only for service of utilities, foam

plastics shall be protected against ignition buy 1 _-inch-thick (38 mm) mineral fiber

insulation, _-inch-thick (6.4 mm) wood structural panels, 3/8-inch (9.5 mm) particleboard,

Code Citations

Plan Review / Inspection Guidance
_-inch (6.4 mm) hardboard, 3/8-inch (9.5 mm) gypsum board, or corrosion resistant steel

having a base metal thickness of 0.016 inch (0.406 mm).

IRC 2000, Section R318.3

Plastic foam not meeting the requirements of Section R318.1 and R318.2 may be

specifically approved on the basis of one of the following approved tests:

ASTM E 84, FM 4880, UL 1040, ASTM E152, or UL 1715, or fire tests related to actual

end-use configurations. The specific approval may be based on the end use, quantity,

location and similar considerations where such tests would not be applicable or practical.

IRC 2003, Section R314.3

Plastic foam not meeting the requirements of Section R318.1 and R318.2 may be

specifically approved on the basis of one of the following approved tests:

ASTM E 84, FM 4880, UL 1040, NFPA 286, ASTM E152, or UL 1715, or fire tests related

to actual end-use configurations. The specific approval may be based on the end use,

quantity, location and similar considerations where such tests would not be applicable or

practical.

Applicable Material Testing References

ASTM E 84 - Standard Test Method for Surface Burning Characteristics of Building

Materials

UL 1715 – Fire Test of Interior Finish Material.
F1147-E(05/2004) 

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DE-AC36-99-GO10337 

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4. TITLE AND SUBTITLE

Building America Best Practices Series: Volume 1 

5c. PROGRAM ELEMENT NUMBER

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NREL/TP-550-36960 

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BET5.8004 

6. AUTHOR(S)

M.C. Baechler, P.M. Love 

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National Renewable Energy Laboratory 

1617 Cole Blvd. 

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14. ABSTRACT (Maximum 200 Words)

This Building America Best Practices guide book is a resource to help builders large and small build high-quality, 

energy-efficient homes that achieve 30% energy savings in space conditioning and water heating in the hot and 

humid climate. The savings are in comparison with the 1993 Model Energy Code. The guide contains chapters for 

every member of the builder's team. There is also a chapter for homeowners on how to use the book to provide help 

in selecting a new home or builder. 

15. SUBJECT TERMS

Building America; U.S. Department of Energy; hot-humid climate; energy-efficient house; builder's guide; best 

practices; energy savings; 1993 Model Energy Code; water heating 

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Bringing you a prosperous future where energy is clean, abundant, reliable, and affordable

A Strong Energy Portfolio 

for a Strong America

Energy effi ciency and clean, renewable 

energy will mean a stronger economy, 

a cleaner environment, and greater 

energy independence for America. 

Working with a wide array of state, 

community, industry, and university 

partners, the U.S. Department of 

Energy’s Offi ce of Energy Effi ciency 

and Renewable Energy invests in a 

diverse portfolio of energy technologies.

Research and Development 

of Buildings

Our nation’s buildings consume more 

energy than any other sector of the 

U.S. economy, including transportation 

and industry. Fortunately, the opportunities to reduce building energy use—

and the associated environmental 

impacts—are signifi cant.

DOE’s Building Technologies Program 

works to improve the energy effi ciency 

of our nation’s buildings through innovative new technologies and better 

building practices. The program

focuses on two key areas:

• Emerging Technologies 

Research and development of the 

next generation of energy-effi cient 

components, materials, and 

equipment

• Technology Integration

Integration of new technologies 

with innovative building methods 

to optimize building performance 

and savings

For more information contact:

EERE Information Center

1-877-EERE-INF (1-877-337-3463)

www.eere.energy.gov

An electronic copy of this factsheet is 

available on the Building America Web 

site at www.buildingamerica.gov

U.S. Department of Energy

Energy Effi ciency

and Renewable Energy

Building America Program

George S. James • New Construction • 202-586-9472 • fax: 202-586-8134 • e-mail: George.James@ee.doe.gov

Terry Logee • Existing Homes • 202-586-1689 • fax: 202-586-4617 • e-mail: terry.logee@ee.doe.gov

Lew Pratsch • Integrated Onsite Power • 202-586-1512 • fax: 202-586-8185 • e-mail: Lew.Pratsch@hq.doe.gov

Building America Program • Offi ce of Building Technologies, EE-2J • U.S. Department of Energy • 1000 Independence Avenue, S.W. • 

Washington, D.C. 20585-0121 • www.buildingamerica.gov

Building Industry Research Alliance (BIRA)

Robert Hammon • ConSol • 7407 Tam O’Shanter Drive #200 • Stockton, CA 95210-3370 • 209-473-5000 • fax: 209-474-0817 • 

e-mail: Rob@consol.ws • www.bira.ws

Building Science Consortium (BSC)

Betsy Pettit • Building Science Consortium (BSC) • 70 Main Street • Westford, MA 01886 • 978-589-5100 • fax: 978-589-5103 • 

e-mail: Betsy@buildingscience.com • www.buildingscience.com

Consortium for Advanced Residential Buildings (CARB)

Steven Winter • Steven Winter Associates, Inc. • 50 Washington Street • Norwalk, CT 06854 • 203-857-0200 • fax: 203-852-0741 • 

e-mail: swinter@swinter.com • www.carb-swa.com

Davis Energy Group

David Springer • Davis Energy Group • 123 C Street • Davis, CA 95616 • 530-753-1100 • fax: 530-753-4125 •

e-mail: springer@davisenergy.com • deg@davisenergy.com • www.davisenergy.com/index.html

IBACOS Consortium

Brad Oberg • IBACOS Consortium • 2214 Liberty Avenue • Pittsburgh, PA 15222 • 412-765-3664 • fax: 412-765-3738 •

e-mail: boberg@ibacos.com • www.ibacos.com

Industrialized Housing Partnership (IHP)

Subrato Chandra • Florida Solar Energy Center • 1679 Clearlake Road • Cocoa, FL 32922 • 321-638-1412 • fax: 321-638-1439 • 

e-mail: subrato@fsec.ucf.edu • www.baihp.org

National Association of Home Builders (NAHB) Research Center

Tom Kenney • National Association of Home Builders (NAHB) Research Center • 400 Prince George’s Boulevard • 

Upper Marlboro, MD 20774 • 301-430-6246 • fax: 301-430-6180 • toll-free: 800-638-8556 • www.nahbrc.org/ 

National Renewable Energy Laboratory

Ren Anderson • 1617 Cole Boulevard, MS-2722 • Golden, CO 80401 • 303-384-7433 • fax: 303-384-7540 • 

e-mail: ren_anderson@nrel.gov • www.nrel.gov

Tim Merrigan • 1617 Cole Boulevard, MS-2722 • Golden, CO 80401 • 303-384-7349 • fax: 303-384-7540 • 

e-mail: tim_merrigan@nrel.gov • www.nrel.gov

Oak Ridge National Laboratory

Pat M. Love • P.O. Box 2008 • One Bethel Valley Road • Oak Ridge, TN 37831 • 865-574-4346 • fax: 865-574-9331 • 

e-mail: lovepm@ornl.gov • www.ornl.gov

Produced for the U.S. Department of Energy (DOE) by the National Renewable Energy Laboratory, a DOE national laboratory.

December 2004 • NREL/TP-550-36960

Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste.

Visit our Web sites at:

www.buildingamerica.gov www.energystar.gov