BUILDING TECHNOLOGIES PROGRAM 

Energy Performance Techniques 

and Technologies: 

Preserving Historic Homes 

VOLUME 13. BUILDING AMERICA BEST PRACTICES SERIES 

PREPARED BY 

Pacific Northwest National Laboratory 

& Kaufman Heritage Conservation 

February 28, 2011 

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February 28, 2011 • PNNL-20185 
BUILDING AMERICA BEST PRACTICES SERIES 

Energy Performance Techniques 

and Technologies: 

Preserving Historic Homes
 

PREPARED BY 

Pacific Northwest National Laboratory 

Michelle Britt, Michael C. Baechler, 

Theresa Gilbride, Marye Hefty, 

Erin Makela, and Elaine Schneider 

and 

Kaufman Heritage Conservation 

Ned Kaufman, Ph.D. 

February 28, 2011 

Prepared for the U.S. Department of Energy 

under Contract DE-AC05-76RLO 1830 

PNNL-20185 

This report was prepared as an account of work sponsored by an agency of the 

United States Government. Neither the United States Government nor any agency 

thereof, nor Battelle Memorial Institute, nor any of their employees, makes any 

warranty, express or implied, or assumes any legal liability or responsibility for the 

accuracy, completeness, or usefulness of any information, apparatus, product, or 

process disclosed, or represents that its use would not infringe privately owned 

rights. Reference herein to any specific commercial product, process, or service by 

trade name, trademark, manufacturer, or otherwise does not necessarily constitute 

or imply its endorsement, recommendation, or favoring by the United States 

Government or any agency thereof, or Battelle Memorial Institute. The views and 

opinions of authors expressed herein do not necessarily state or reflect those of 

the United States Government or any agency thereof. 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

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You can learn more about Building 

America and download additional copies 

of this document, other best practices, 

research reports, and case studies at 

www.buildingamerica.gov 

Preface 

This guide is a resource to help contractors renovate historic 

houses, while addressing issues such as building durability, indoor 

air quality, and occupant health, safety, and comfort. The best 

practices described in this document are based on the results 

of research and demonstration projects conducted by Building 

America’s research teams. Building America brings together the 

nation’s leading building scientists with over 300 production 

builders to develop, test, and apply innovative, energy-effi cient 

construction practices. 

Acknowledgments 

The U.S. Department of Energy’s (DOE’s) Building America 

Program comprises public-private partnerships that conduct 

systems research to improve overall house performance, increase 

housing durability and comfort, reduce energy use, and increase 

energy security for America’s homeowners. 

Program activities focus on finding solutions for both new and 

existing homes, as well as integrating clean onsite energy systems 

that will allow the homebuilding industry to provide homes 

that produce more energy than they use. In addition to DOE 

management and staff, the Building America Program includes 

15 consortia, four national laboratories, and hundreds of builders, 

research organizations, manufacturers, and service providers. 

The DOE Building America Program funded the development 

of this guide. DOE also funded the Building America consortia 

and national laboratories to conduct the research that forms the 

basis for these recommendations. The consortia have taken on the 

hard work of applied research, field testing, training builders, and 

transforming results into building practices. Numerous drawings, 

descriptions, photos, and case studies originated with these research 

partners. Examples from these partners are used throughout this 

guide to illustrate construction best practices. 

4 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Contents 

Preface ............................................................................................................................................................................i
 

Acknowledgments ....................................................................................................................................................i
 

1. Introduction............................................................................................................................................................ 1
 

2. Background: The Historic Building Context ........................................................................................ 3
 

Identification and Preservation of Historic Places ...............................................................................4
 

Related Local and State Resources ............................................................................................................ 5
 

Building Codes ...................................................................................................................................................... 6
 

Preservation Project Classifications and Related Standards ......................................................... 7
 

3. Planning the Historic House Whole-House Energy Retrofi t ....................................................... 9
 

The Energy Audit: A Vital Step in Retrofitting a Historic House ................................................ 10
 

Finding a Contractor to Retrofit a Historic House ..............................................................................11
 

4. Historic House Upgrades..............................................................................................................................12
 

Making the Most of the Potential of the Original Design ................................................................12
 

Air Sealing..............................................................................................................................................................13
 

Insulation Moisture Issues in the Attic and Basement ......................................................................15
 

Roofs .........................................................................................................................................................................16
 

Walls ..........................................................................................................................................................................18
 

Windows .................................................................................................................................................................19
 

Systems for Heating and Cooling a House ............................................................................................21
 

Lighting ..................................................................................................................................................................24
 

Other Considerations During an Energy Retrofi t ..............................................................................25
 

Porches ...................................................................................................................................................................25
 

Landscaping and Siting ................................................................................................................................25
 

Seismic Retrofi ts ................................................................................................................................................26
 

5. Conclusion ...........................................................................................................................................................27
 

References.................................................................................................................................................................28
 

Appendix — Health and Safety Concerns................................................................................................ 30
 

February 28, 2011 i
 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

1. Introduction 

The U.S. Department of Energy’s (DOE’s) Building America 

Program is an industry-driven research program that promotes the 

accelerated development and adoption of advanced building energy 

technologies in new and existing homes. The program gives home 

builders and remodelers access to the nation’s leading building science 

developments to build high-performance homes that use less energy, 

are more comfortable, healthier to live in, and long lasting. This guide 

is a resource for contractors and owners of historic houses who want 

to improve the energy efficiency while protecting historic character. 

Although older buildings require attention and maintenance, they 

repay the effort as assets that gain value over time. More and more, 

homeowners value historic houses for their appealing aesthetic 

character, lifestyle advantages, and quality of life. Depending on the 

circumstances, these advantages may include beautiful ornamentation, 

spacious room proportions, natural lighting, outdoor spaces, and— 

not least of all—a feeling of history, tradition, and permanence. 

Furthermore, time has shown that even the most unappreciated historic 

styles eventually become popular; so, even if you have mixed feelings 

about the appearance and design of a historic house, bear in mind 

before doing anything to diminish its historic character, that the next 

occupants may love that style—and that may affect the selling price. 

Special energy-retrofitting challenges include preserving the home’s 

historic features, being aware of and adhering to regulations related 

to historic designations, and addressing health and safety issues. 

Building America’s research provides field-tested approaches to help 

address these challenges. 

Sponsored by the U.S. Department 

of Energy, the Building America 

Program is industry-driven 

research designed to accelerate 

the development and adoption of 

advanced building energy technologies 

in new and existing homes (for more 

information, see www.buildingamerica. 

gov.) Building America’s renovation 

case studies illustrate proven 

techniques applied to historic houses 

in a variety of climates (for published 

examples, see www.eere.energy. 

gov/buildings/building_america/ 

climate_specifi c_publications.html). 

Retrofitting homes that are designated 

as “historic” may require a formal 

review process, but all homes deserve 

a thoughtful approach to maintaining 

their character. 

February 28, 2011 1 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Retrofitting homes that are designated as “historic” may require a 

formal review process, but all homes deserve a thoughtful approach 

to maintaining their character. If you are a contractor, share this 

guide with your clients so they can understand how you will make 

their homes more comfortable, durable, and energy effi cient, while 

respecting the homes’ historic qualities. 

Following Building America-sponsored research, this document 

focuses on planning energy-efficient improvements for historic 

houses by combining energy-efficient best practices with the 

process of historic renovation. The background for retrofi tting 

and preserving older homes that may be designated as “historic” is 

introduced. Steps to consider when planning a whole-house energy 

retrofit are highlighted. Strategies for maximizing the potential 

energy efficiency of an original house design and preserving its 

character are presented. Aspects of retrofitting a historic house 

while preserving its character are addressed. Finally, the document 

describes health and safety concerns related to past building 

materials and practices. Refer to the resources cited throughout 

this guide for additional information. This document does not 

delve into the details of installation techniques. These practices 

vary depending on construction materials, methods, and climate 

zones, but references are provided so readers can access 

installation information. 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

2. Background: 


The Historic Building Context
 

Improving energy performance using Building America’s qualitymanagement practices and whole-house energy approach helps 

deliver more energy-efficient and durable historic houses. The 

historic nature of a home requires additional thought and sensitivity 

to its construction and design features. When contemplating a historic 

house remodel, it is important to determine whether there is any 

possibility the property may be historically significant. Contact the 

local building and planning departments to inquire about a local 

historic preservation ordinance and whether: 

• THE HOME IS ELIGIBLE FOR LISTING IN THE 

NATIONAL REGISTER OF HISTORIC PLACES 

•THE PROPERTY IS LOCATED WITHIN A HISTORIC 

NEIGHBORHOOD OR DISTRICT 

• ANY LOCAL OR STATE HISTORIC ORDINANCES APPLY. 

Understanding the regulatory requirements for preserving the 

character-defining features of the home is as important as assessing 

the home’s inherent energy-conserving potential. It is important 

to improve historic houses through maintenance, upgrading, and 

environmental retrofitting, but do not destroy its historic fabric 

and regret it later. 

Because effective retrofitting considers the historic character of a 

home and the materials used to construct it, the builder may need 

to confer with a historic preservation consultant. The State Historic 

Preservation Office and local historic preservation office, society, or 

commission may be able to identify preservation design consultants 

and restoration contractors who have experience with similar 

projects. As preservationists, they want to preserve historic structures 

from demolition or degradation. They can help determine how to 

best blend retrofitting additions with the existing decorative details 

and historic features of the home without damaging its character. 

Builders need to be familiar with the identification and preservation 

of historic houses, related state and local resources, how codes might 

affect retrofitting, and any federal permitting issues. If working with 

preservationists on the project team, they also need to share a common 

language as they work together to assess, plan, and decide how to 

retrofit the home. This section provides an overview of these needs. 

www.nps.gov/nr/publications/index.htm 

A good reference for anyone 

considering working with a historic 

house is the National Register 

Bulletin 15, “How to Apply the 

National Register Criteria for 

Evaluation,” which is available both 

in print and online (http://www.nps. 

gov/nr/publications/bulletins/nrb15/). 

The National Park Service also 

developed The Secretary of the 

Interior’s Standards for the Treatment 

of Historic Properties with Guidelines 

for Preserving, Rehabilitating, 

Restoring, and Reconstructing 

Historic Homes (hereafter Secretary’s 

Standards; see www.nps.gov/history/ 

hps/tps/standards_guidelines. 

htm). These standards and design 

guidelines have been adopted by 

state preservation agencies and 

by many local ordinances and 

programs (see www.energysavers. 

gov/your_home/energy_audits/ 

index.cfm/mytopic=11160 and http:// 

apps1.eere.energy.gov/buildings/ 

publications/pdfs/building_america/ 

ba_airsealing_report.pdf). 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

“The [National Register] 

criteria do not describe 

‘exceptional,’ nor should they. 

Exceptional, by its own defi nition, 

cannot be fully catalogued or 

anticipated. It may refl ect the 

extraordinary impact of a political or 

social event. It may be a function of 

the relative age of a community and its 

perceptions of old and new. It may be 

represented by a building or structure 

whose developmental or design value 

is quickly recognized as historically 

significant by the architectural or 

engineering profession. It may be 

reflected in a range of resources for 

which a community has an unusually 

strong associative attachment.” 

For more information go to 

www.nps.gov/history/nr/publications/ 

bulletins/nrb22/nrb22_I.htm 

Identification and Preservation of Historic Places 

The National Register of Historic Places (NRHP or National 

Register)—a division of the National Park Service (NPS)—is 

the authority on the topic of historic buildings. According to 

the National Register criteria, homes over 50 years old may be 

considered historic if they were designed by a master architect, 

have high aesthetic value, typify a style or type of construction, 

or are associated with significant individuals or historic trends. 

In particular, the National Register criteria (www.nps.gov/nr/ 

publications/bulletins/nrb15/nrb15_2.htm) for evaluation of 

historic sites state that: 

The quality of significance in American history, architecture, 

archaeology, engineering, and culture is present in districts, sites, 

buildings, structures, and objects that possess integrity of location, 

design, setting, materials, workmanship, feeling, and association, and: 

• THAT ARE ASSOCIATED WITH EVENTS that have made a 

significant contribution to the broad patterns of our history; or 

• THAT ARE ASSOCIATED WITH THE LIVES of signifi cant 

persons in or past; or 

• THAT EMBODY THE DISTINCTIVE CHARACTERISTICS 

of a type, period, or method of construction, or that represent 

the work of a master, or that possess high artistic values, or 

that represent a significant and distinguishable entity whose 

components may lack individual distinction; or 

• THAT HAVE YIELDED OR MAY BE LIKELY TO YIELD 

INFORMATION important in history or prehistory. 

Homes under 50 years old can also be considered historic, but 

they must have “exceptional” significance, with “exceptional” 

referring to the recognition of locally significant historic resources 

that, by appearance or association with persons or events, provide 

communities with a sense of past and place. 

Homes located in historically designated neighborhoods must follow 

the requirements of the district even though specific homes may not 

meet the National Register criteria for eligibility. 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Related Local and State Resources 

Before making any energy improvements on a historic house, it is 

important to fully understand the local, state, and federal rules and 

regulations that may govern changes to the historic house. Resources 

for this information will vary by community, but start by contacting 

the local building department, planning department, or historic 

preservation office, society, or commission. 

Although the criteria for defining “historic” may have been 

developed by a federal agency, it is most often a local ordinance 

that affects a project. If the jurisdiction has adopted by ordinance a 

historic district, neighborhood, or a listing of historic houses, there 

will be design guidelines to follow, and a review board may need to 

evaluate and approve the project before a building permit may be 

issued. The design review may carry extra costs that the contractor 

or owner needs to factor into the budget. 

For example, Eureka, California, originally settled in the mid-to late1800s, has a heritage rich in lumber history, as is reflected in its stock 

of historic houses. If you were considering a project on an existing 

home in Eureka, a call to the building or planning department (or 

visit to its website: www.ci.eureka.ca.gov/depts/cd/permits_n_forms.asp) 

would provide you with the Historic Preservation Ordinances 

administered by the planning department. The information found on 

the website would tell you the Historic Preservation Commission is 

responsible for the following: 

•	 MAINTAINING A LIST OF LOCALLY, REGIONALLY, AND/OR 

NATIONALLY SIGNIFICANT PROPERTIES AND DISTRICTS 

called the “Local Register of Historic Places.” 

•	 HAVING AUTHORITY TO REVIEW APPLICATIONS 

for additions, alteration, new construction, or demolition of all or 

part of any structure, or landscape element (such as historic walls 

and trees designated in the Historic Preservation Application) that 

is located on a property listed in the Local Register of Historic Places. 

•	 HAVING THE AUTHORITY TO REVIEW AND MAKE 

DECISIONS for all requests from property owners to have 

property placed in, or removed from, the Local Register 

of Historic Places (City of Eureka, Historic Preservation 

Packet_2010). 

The Magdalena Zanone House 

Photo by Ron Kuhnel 

The federal government does 

not monitor the renovation 

of privately funded historic 

buildings. All regulations directly 

affecting the project can be found at 

the local and state levels. 

February 28, 2011 5 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

A state’s SHPO contact information 

can be found through the National 

Conference of State Historic 

Preservation Offi cers 

(www.ncshpo.org/fi nd/index.htm#top). 

Regional and local guides will provide 

information specific to the climate and 

building materials of your region. 

Be sure to confi rm whether 

local or regional design guides 

exist; these will address local 

climate conditions, locally specifi c 

building methods and construction 

practices over time, and often local 

building materials. For example, the 

Sustainable Solutions for Historic 

Houses in Northern California (www. 

epa.gov/brownfi elds/sustain_plts/ 

reports/green_home_guide_fi nal.pdf), 

addresses local climate issues and the 

extensive use of redwood. 

A resource for information 

on building energy codes is 

www.energycodes.gov. 

If the planning or building department in your community uses a 

similar approach, verify whether the property in question is listed 

and determine the associated process for application submittal, 

review, public hearing, and decision by the commission prior to 

being granted a building permit. Any or all of these steps will affect 

the budget and design process. 

As noted earlier, the ordinances that affect your project will be local, 

but they often rely on the Secretary’s Standards for the treatment 

of historic properties and guidelines for preserving, rehabilitating, 

restoring, and reconstructing historic houses. In the Eureka, 

California example, the review process includes a review of the 

project to ensure consistency with the Secretary’s Standards. Other 

jurisdictions have developed their own standards you will need to 

work with. 

In addition to being aware of local restrictions, contact the State 

Historic Preservation Office (SHPO) to determine whether specifi c 

historic preservation design guidelines have been developed for your 

state. The SHPO will also have information about any historical 

surveys that have been completed or significant issues that have been 

raised regarding the property you are considering renovating, and 

can provide guidance in determining appropriate local resources. 

Building Codes 

Building permits may be required for energy improvements, and 

the historic nature of the project may affect how the local building 

codes apply to the project. The local code official will provide 

information about which codes have been adopted, and how 

they are enforced relative to historic properties. For example, the 

International Residential Code (IRC), which regulates construction 

of single-family houses, two-family houses (duplexes), and buildings 

consisting of three or more townhouse units, has been widely 

adopted by jurisdictions nationwide. 

The International Energy Conservation Code (IECC) has also 

been widely adopted, and, like the IRC, it applies to building 

additions, alterations, and repairs. However, as Section 101.1.2 of 

the 2009 IECC states, properties that are listed, locally designated 

as historic, or for which an opinion has been granted that it is 

eligible to be listed are exempt from the IECC. This is particularly 

important when considering energy retrofit projects, such as 

windows and insulation. 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Historic Rehabilitations 

Some jurisdictions have also adopted the International Existing 

Building Code (IEBC), which is specific to the use and reuse of 

existing buildings, both residential and commercial, with Chapter 11 

being specific to historic buildings. It can be adopted by jurisdictions 

as a means to codify exceptions for historic buildings, and it can be 

used in historic districts. An important distinction is that the IECC 

excludes properties that “could be” listed, while the IEBC in general 

applies to all historic properties (IEBC Chapter 11, Historic Buildings, 

applies only to listed properties). If your jurisdiction has adopted 

the IEBC, it is important to clarify which code will apply to your 

project, because the IEBC, IECC, and IRC interface and overlap. 

Preservation Project Classifi cations 

and Related Standards 

While contractors, building officials, and codes classify projects as 

additions, alterations, or repairs, depending on how extensive the 

work is, preservationists typically classify projects as preservation, 

rehabilitation, restoration, or reconstruction, based on the goals 

of the project and resulting impacts on the historic integrity of the 

building. Before the project begins, decisions need to be made about 

how the property will be used, and if there are historic features that 

can be retained. The National Park Service provides defi nitions to 

help determine the project classifications. Note that additions and 

alterations are both considered rehabilitation. 

February 28, 2011 7 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

The National Park Service 

identifi es fi ve examples 

to help illustrate these 

classifi cations. 

Preservation — Jacksonville National 

Historic District (www.nps.gov/history/ 

hps/workingonthepast/case_studies/ 

jacksonville1.htm). 

Rehabilitation 1 — Baker Historic 

District (www.nps.gov/history/hps/ 

workingonthepast/case_studies/ 

bakercity1.htm). 

Rehabilitation 2 — Ladd’s Addition 

Historic District (www.nps.gov/history/ 

hps/workingonthepast/case_studies/ 

laddsaddition1.htm). 

Restoration — Monteith Historic 

District (www.nps.gov/history/hps/ 

workingonthepast/case_studies/ 

monteith1.htm). 

Reconstruction — Oswald West 

Coastal Retreat (www.nps.gov/history/ 

hps/workingonthepast/case_studies/ 

oswaldwest1.htm). 

•	 PRESERVATION focuses on the maintenance, stabilization, and 

repair of existing historic materials and retention of a property’s 

form as it has evolved over time. The historic features of the home 

are not limited to one time period. 

•	 REHABILITATION acknowledges the need to alter or add to 

a historic property to meet continuing or changing uses while 

retaining the property’s historic character. 

•	 RESTORATION depicts a property at a particular period of time 

in its history, while removing evidence of other periods. Restoring 

a home is significantly different from preserving or rehabilitating 

it; less flexibility is allowed in “modernizing” the building and 

mixing elements from various time periods. All modern changes to 

the house are removed so that only one period is interpreted. 

•	 RECONSTRUCTION re-creates vanished or non-surviving 

portions of a property for interpretive purposes. While houses as 

a whole aren’t typically reconstructed, independent elements of a 

home, i.e., chimneys, porches, and so forth, can be and often are 

reconstructed. 

It is important for contractors and homeowners to know how 

to historically categorize their project, because the local or 

state ordinance may base the design review of the project on 

this classification and the applicable design guidelines from the 

Secretary’s Standards. 

8 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

3. Planning the Historic House 

Whole-House Energy Retrofi t 

Armed with information about any local ordinances or resources 

and applicable building codes, planning for the retrofit can begin. 

Don’t forget that, as old-fashioned as it may seem, a historic house 

actually may have some environmental advantages that would be 

hard to duplicate now: high-quality timber and windows, non-toxic 

interior materials, heat-retaining masonry walls, mature shade trees, 

through-ventilation, natural lighting, and so forth. Make these the 

basis of your environmental retrofit. But most of all, remember that 

the mere fact the house exists represents an environmental plus: you 

don’t have to build a new one! By retrofitting the old one instead of 

demolishing and building new, you are saving valuable materials, 

reducing the amount of waste going into the landfi ll, and—above 

all—reducing carbon use and greenhouse gas emissions. As an added 

bonus, you are enhancing the character of your community. 

With these advantages in mind, consider how the retrofit of the 

historic home will differ from retrofitting a more contemporary 

home. As with their modern counterparts, historic houses operate 

as systems, but they work differently from contemporary homes, 

and the systems vary depending on the era and style of architecture. 

Understanding how these systems work and diagnosing their 

needs are important steps in retrofitting historic houses. Using an 

integrated design approach is just as important in retrofits as it is in 

new construction. 

Building America’s systems approach to home design acknowledges 

that as buildings become increasingly efficient, the interactions of 

all of the home’s components and subassemblies must be taken 

into account to maximize performance and avoid unintended 

consequences. This “whole-building” approach recognizes that 

changes in one or a few components can dramatically change how 

other components perform, thereby affecting the overall building 

energy use, comfort, and durability. The integrated design process 

used to improve the home’s efficiency and performance can also be 

applicable to remodeling and preserving historic houses. 

Whole-building design suggests that a single change in a home’s 

structure or other systems can affect the rest of the home. 

A key idea behind integrated 

planning is that decisions about all 

building systems, including equipment 

selection, sizing, and placements, 

are made within the design process, 

not as afterthoughts in the fi eld. The 

decisions are made with the help of 

analytical tools and the input of all 

relevant disciplines. Rather than a linear 

traditional process, the integrated 

process involves looping in ongoing 

input from relevant sources. 

The REGREEN Program is a 

partnership between the American 

Society of Interior Designers and U.S. 

Green Building Council. The remodeling 

guidelines address sustainable 

remodeling practices and have been 

applied to historic houses. 

(www.regreenprogram.org). 

42,226 homes have been built to 

date using technologies and strategies 

developed through Building America 

research to construct high-quality, 

energy-effi cient homes (http://apps1. 

eere.energy.gov/buildings/building_ 

america/cfm/project_locations.cfm). 

February 28, 2011 9 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Sealing air leaks may result in a need 

for ventilation. 

Experienced auditors or HVAC 

contractors will conduct computer 

simulations—ACCA Manual J runs—to 

determine the how large the furnace 

and air conditioner should be, based on 

their inspection and fi ndings. 

For example, adding insulation and sealing air leaks can improve the 

energy efficiency of a home and improve its comfort and durability. 

However, every change made to the building’s envelope (walls, fl oors, 

and ceiling) will affect the performance, health, and safety of the 

house. Sealing air leaks in the building envelope without providing 

appropriate ventilation can cause pressure imbalances or negative 

pressure inside the house. This negative pressure can cause fi replaces, 

furnaces, or other fuel-burning appliances to release dangerous fumes 

into the house instead of exhausting them through chimneys or fl ues. 

A home energy audit is conducted to help understand how a historic 

house operates as a system and diagnose its particular needs. As 

described below, a certified contractor or auditor conducts the 

audit and understands how historical systems work together to 

keep a house operating as it should, and how changes will affect the 

whole system. 

The Energy Audit: 


A Vital Step in Retrofitting a Historic House
 

Whole-house energy audits and inspections typically do the following: 

•	 ASSESS how much energy the home consumes. 

•	 DETERMINE what measures to take to make the home more 

energy effi cient. 

•	 EVALUATE whether basic health and safety criteria are met. 

The audit should be conducted by a certified professional, preferably 

one with experience working with older homes and historic 

preservation issues. (See the next section for how to find a certifi ed 

auditor.) The auditor should fi rst confirm whether the National 

Register has listed the home as a historic building. The audit will 

then identify problems that may, when corrected, save signifi cant 

amounts of money and energy over time. It will pinpoint where the 

house is losing energy and determine the efficiency of the home’s 

heating and cooling systems. The audit may also identify ways to 

conserve hot water and electricity. 

A professional auditor uses a variety of techniques and diagnostic 

equipment to measure how a house performs in ways that cannot 

be seen by eyes alone. These tests may include a blower door test to 

determine air leakage and house pressurization problems, tests to 

detect drafts and the effectiveness of the ducts, combustion safety 

testing, and carbon monoxide sampling. 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

The auditor will also estimate the costs of making various 

improvements and will use a computer program to estimate the 

annual savings expected from each improvement. The cost of the 

measures divided by the annual savings will provide the “simple 

payback” or how many years the measures will take to pay for 

themselves. Some energy measures may be as simple as stopping 

unwanted heat transfers by tightening leaky windows and doors. 

Addressing the simple fixes will reduce the number of big-ticket fi xes 

needed. As experienced energy auditors know, for big-ticket fi xes, 

like new furnaces, it is important to weigh all of the available options 

and install the smallest system needed. 

The recommended energy-saving improvements derived from 

the audit results must be weighed against their impacts on the 

historic character of the home and associated regulations, and any 

retrofitting decisions must take into account the unique costs of 

historic house, such as custom windows. Note, the cost built into a 

standard audit may not capture the customized work needed for a 

historic house. 

More importantly, historic houses may contain open-combustion 

appliances, such as gas-burning furnaces that use the air in the room 

for the fuel-burning process. Safety problems of open-combustion 

appliances can be exacerbated when retrofitting a home. When 

cracks and leaks that once let in air are sealed, carbon monoxide and 

air pollutants from cleaning chemicals, combustion appliances, and 

off-gassing household products can build up, creating an unhealthy 

and even dangerous environment in the home. 

These older homes also may have dry rot and moisture problems. 

A certified contractor follows an auditing process that ensures 

that any health, safety, and moisture problems are solved during 

the whole-house energy retrofit. With ongoing attention to the 

homeowner’s health and safety, the contractor also identifi es any 

potential problems related to historically used materials, such as lead 

and asbestos, that can cause major health problems (see Health and 

Safety Concerns in the Appendix). 

Finding a Contractor to Retrofit a Historic House 

There are two nationally recognized energy certifications for home 

energy auditors and contractors: the Building Performance Institute, 

Inc. (BPI) Building Analyst certification and the Residential Energy 

Services Network (RESNET) Home Energy Rating System Rater 

certification. To date, BPI certification has focused on understanding 

the building science of retrofi tting existing homes, and BPI will 

Atmospheric combustion 

For more information about 

home energy assessments and air 

sealing, see www.energysavers.gov/ 

your_home/energy_audits/index. 

cfm/mytopic=11160 and the Building 

America air sealing document (http:// 

apps1.eere.energy.gov/buildings/ 

publications/pdfs/building_america/ 

ba_airsealing_report.pdf). 

February 28, 2011 11 

11 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Shutters and awnings 

be the best resource for historical home energy audits. BPI is a 

nonprofit organization that accredits auditors, contractors, and 

other building professionals. Auditors or building analysts specialize 

in evaluating building systems and potential energy savings in 

homes. The certified BPI Building Analyst energy auditor has passed 

both written and field exams, and must recertify every 3 years. 

Contractors learn about building systems and are trained to install 

energy-efficiency measures. For more information about BPI’s 

standards and credentials for retrofitting work, see www.BPI.org. 

A certified professional home inspector who has experience working 

with historic houses can be found by contacting the local historical 

society for suggestions. The Historic Building Inspectors Association 

is another excellent resource depending on its availability in your 

local area (also see http://inspecthistoric.org). 

4. Historic House Upgrades 

Improving energy efficiency in a historic house involves paying 

careful attention to how to make the most of its original design 

features , ensuring the durability of the home, and preserving the 

home’s character during the remodel. 

Making the Most of the 

Potential of the Original Design 

Building America’s research clearly indicates that climate zones affect 

building and retrofitting decisions. For example, radiant barriers are 

not recommended in cold climates because of the moisture problems 

they can cause. Historic builders intuitively understood some of these 

climate-specific features, and most of the features should be retained 

during the energy retrofit. For example, builders often incorporated 

features into the site and building design that helped moderate interior 

temperatures or provided for comfortable outdoor living areas— 

features like operable windows, awnings, heat-retaining masonry 

walls, high ceilings, through-ventilation, shade trees, and so forth. 

These features are still the basis of good design, and contemporary 

homeowners will benefit from maximizing their potential in terms of 

comfort or energy savings, while also retaining the historic character 

of the home. The National Trust for Historic Preservation (NTHP) 

identifies the following historically useful cold and hot climate features 

(also see www.preservationnation.org): 

•	 SHUTTERS AND AWNINGS used in both hot and cold climates, 

with adjustable louvers allow for air circulation and block solar 

gain on hot days. Operable shutters reduce drafts on colder days 

and block solar gain on hot days. Post-Katrina construction in 

12 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

New Orleans and on the Gulf Coast is seeing the reinstitution of 

more historic louver shutters that admit air, while providing shade. 

Removable or permanently attached awnings protect the windows 

from solar gain on hot days, allowing for winter solar gain. 

•	 OVERHANGS, EAVES, AND COVERED PORCHES provide 

shaded outdoor living space and protect the walls from the hot 

summer sun and precipitation. If siding is being replaced, an 

overhang could allow for the addition of exterior rigid foam to 

help insulate the walls. 

•	 SEASONALLY SHADED INTERIOR COURTYARDS provide 

outdoor living space for hot summer days and warm protected 

areas on cooler days. 

•	 BRICK AND ADOBE provided thermal mass to moderate the 

temperature swings, releasing heat gained during the day into the 

cooler night. 

•	 CROSS VENTILATION is encouraged with the use of doublehung windows both upstairs and downstairs, creating an air fl ow 

through the house and exhausting hot air from the upper story. 

•	 VEGETATION is used to provide windbreaks and provide shade 

for the hot summer days. Evergreen trees provide year-round wind 

protection while deciduous trees provide seasonal shade, allowing 

for winter solar gain. 

Taking advantage of retaining these features will benefi t the 

home by preserving its historic integrity, increasing the comfort 

of the homeowners, and reducing the need for additional energyeffi ciency features. 

Air Sealing 

Whether a home is located in a hot and dry or very cold climate, one 

of the least expensive and potentially most effective energy-retrofi tting 

measures is air sealing. The Building America’s Best Practices Guide, 

Air Sealing: A Guide for Contractors to Share with Homeowners (http:// 

apps1.eere.energy.gov/buildings/publications/pdfs/building_america/ 

ba_airsealing_report.pdf), provides comprehensive guidance for air 

sealing existing homes. The guide helps identify ways to make homes 

more comfortable, more energy efficient, and healthier to live in. 

It also identifies the steps to take to seal unwanted air leaks while 

ensuring healthy levels of ventilation and avoiding sources of indoor 

air pollution. Studies show that air-sealing measures described in the 

guide can typically achieve whole-house energy savings of 10% to 20% 

over pre-retrofit energy usage. In older homes or homes with greater 

air leakage, the savings may be much greater. 

Miller placed rigid foam insulation and 

a new three-coat stucco finish over the 

original adobe walls but kept the historic 

masonry parapet visible to retain the 

home’s southwestern character. 

February 28, 2011 13 

13 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

The Building America Asdal case study 

illustrated the use of rigid foam sealed in 

place with spray foam to insulate the band 

joists (top) and the use of spray foam 

around piping and wiring holes (www.eere. 

energy.gov/buildings/building_america/ 

cold_case_studies.html). 

Establishing the continuity of the air barrier system of a building 

is the goal of air sealing, which should be an integral part of all 

aspects of the retrofit from roof to cellar to window repair. However, 

it is important to remember the building is functioning as a system, 

and all parts of the system must work together to keep moisture 

from causing damage to the structure or being a health hazard to the 

occupants. As an air quality issue, the growth of mold and mildew 

may be exacerbated by the reduction in air leakage, but air sealing 

in general does not inhibit drying of the structure, unless it results in 

encapsulating the structure with vapor-impermeable material. Mold 

and mildew growing in moist areas may cause allergic reactions 

and damage building materials. If the air movement through the 

structure was allowing parts of the structure to dry out, sealing the 

building may require the addition of mechanical ventilation. 

Two key examples of air sealing in historic houses and approaches 

taken to avoid indoor air quality problems are described below. 

Pittsburgh Depression Era Bungalow 

The Building America Asdal Builders, LLC Pittsburgh Case Study 

(Pittsburgh; http://apps1.eere.energy.gov/buildings/publications/pdfs/ 

building_america/ba_cs_retrofi t_asdal_builders.pdf) demonstrates 

the way one change can trigger another in the house as a system. 

The renovators caulked the sill plates, air sealed the unfi nished 

basement walls, and sealed the band joists with spray foam and 

rigid foam insulation. The extensive air sealing provided a very 

“tight” house, demonstrated by blower door tests. However, the tight 

house necessitated another step—providing adequate combustion 

air. The natural gas boiler used combustion air drawn from inside 

the home, thereby drawing oxygen from the living environment—a 

health concern in tightly sealed homes. The solution was to install a 

new boiler, with “power venting” drawing combustion air from the 

outside. 

Newburgh 18th Century Brick 

The Building America Habitat for Humanity, Newburgh, NewYork 

Case Study (Habitat Newburgh; http://apps1.eere.energy.gov/ 

buildings/publications/pdfs/building_america/ba_cs_retrofi t_ 

newburgh_habitat.pdf) illustrates how to handle historical elements 

that are also air leakage problems. The goal was to reach a fi nal 

infiltration rate of 0.60 air changes per hour—the ENERGY STAR 

requirement for new homes. The fireplace contributed to the air 

leakage, but was a historical element of the home. The solution was 

to close off the fireplace and carefully seal around it, but retain it as 

a decorative element for its historical value. 

14 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

When air leakage is significantly reduced, mechanical air ventilation 

may be necessary. American Society of Heating, Refrigerating and 

Air-Conditioning, Inc. (ASHRAE) Standard 62.2 for ventilation 

and acceptable indoor air quality in low-rise residential buildings 

provides the related standards and guidelines (ASHRAE 2007). 

Installing ENERGY STAR exhaust fans on timers can provide 

adequate ventilation. 

Insulation Moisture Issues 

A second key energy-saving practice for existing homes is installing 

increased insulation in basements, above-grade walls, and attics. The 

energy audit will have provided information about air leakage, moisture 

issues, and desired insulation levels. Attic and basement insulation, 

in particular, can increase the energy efficiency of a home without 

damaging its historical integrity, and the installation of insulation often 

can occur without affecting architectural features or details. However, 

altering the air-sealing and thermal properties of attics and basements 

can result in significant moisture issues. DOE’s Building Technologies 

Program “Insulation Fact Sheet” (www.ornl.gov/sci/roofs+walls/ 

insulation/ins_06.html) describes the issue as follows: 

When moist air touches a cold surface, moisture may form as 

condensation. If moisture condenses inside a wall, or in your attic, 

you will not be able to see the water, but it can cause a number of 

problems. Adding insulation can either cause or cure a moisture 

problem. When you insulate a wall, you change the temperature 

inside the wall. That can mean that a surface inside the wall, such 

as the sheathing behind your siding, will be much colder in the 

winter than it was before you insulated. This cold surface could 

become a place where water vapor traveling through the wall 

condenses and leads to trouble. The same thing can happen within 

the attic or in a crawlspace or basement. With careful design the 

new temperature profile could prevent condensation and help keep 

your walls or attic drier than they would have been. 

Massachusetts 1760 Cape 

Basement walls may have historical significance, contributing to the 

difficulty of adding exterior insulation. Basement walls, typically 

found in colder climates, can present other specific challenges as 

demonstrated in The Building America National Grid Deep Energy 

Retrofit Pilot Program: Clark Residence, Belchertown, Maine (Clark 

Residence; www.buildingscience.com/documents/case-studies/ 

cs-ma-ngrid-deep-energy-retrofi t?topic=resources/retrofi ts). Prior 

to the retrofit, there were occasions of standing water in the 

Clark Residence basement. Trenching, piping, and gravel mitigated 

For more information on air 

sealing, refer to Building America’s Best 

Practices Guide, Air Sealing: A Guide for 

Contractors to Share with Homeowners 

(http://apps1.eere.energy.gov/buildings/ 

publications/pdfs/building_america/ 

ba_airsealing_report.pdf). 

In the Clark Residence, the 

basement is conditioned with 3 to 

5 inches medium-density spray foam 

insulation applied directly to fi eld 

stone and concrete foundation walls. 

Spray foam insulation is painted with 

ignition barrier paint. A 12-inch-high 

strip of 2-inch foam insulation at the 

slab edge provides a thermal break 

and allows foundation walls to drain to 

the sub-slab drainage system. Several 

trenches with drainage pipes and fi lled 

with gravel carry bulk water to drain. 

The new cast concrete basement fl oor 

slab is installed over 6-mil poly, 2-inch 

foam insulation, and a continuous bed 

of gravel. 

February 28, 2011 15 

15 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

The Building America New Bedford 

Farmhouse case study illustrates signifi cant 

energy retrofits while maintaining the 

historic character of the building 

(www.buildingscience.com). 

The National Trust for Historic 

Preservation offers guidance in 

weathering roofs of historic houses 

(www.preservationnation.org/issues/ 

weatherization/roofi ng/). 

the drainage. The retrofit solved a potential condensation problem 

on the slab and walls by insulating with 3 to 5 inches of mediumdensity spray foam applied directly to the field stone and concrete 

foundation walls and adding a gravel base, a vapor barrier, and rigid 

insulation beneath the new slab. 

Roofs 

A leaky roof will set the stage for damage, decay, and potential 

health and safety issues in a house. Repairing a leaky roof can 

provide an opportunity to add insulation. The energy audit and roof 

inspection should provide the information needed to determine the 

performance of the roof, identifying repair needs or the potential for 

increasing insulation levels. The audit should answer key questions, 

like those of the NTHP’s Start with the Roof – A Guide to Keeping 

Weather Tight (www.preservationnation.org/issues/weatherization/ 

roofi ng/additional-resources/nthp_roofi ng.pdf): 

• Is my roof energy effi cient? 

• How do I know if my roof is failing? 

• What type of roof form is on my building? 

• When replacing my roof, do materials matter? 

In addition to answering these questions, when planning to re-roof 

consider how the pitch and materials of the roof distinguish its 

historical period and character. In a historic house, the overall 

shape, pitch, and construction of the roof, as well as its framing 

members may also have historic quality, because of the materials or 

construction methods used. These elements may limit the available 

options for adding insulation or other improvements. 

Examples of reducing energy use by air sealing and insulating the 

roofs of historic houses are described below. 

Massachusetts Mid-19th Century Farmhouse 

The Building America Bedford Farmhouse High-Performance 

Retrofi t Prototype (Bedford Farmhouse; www.buildingscience.com/ 

documents/case-studies/cold-climate-bedford-farmhouse-retrofi tcase-study), demonstrates “massive energy use reductions in a type 

and age of building that is widespread in the region. The project 

also demonstrates the application of specific high performance 

techniques to an older building. By respecting and maintaining 

the historic character of the building and elevating its aesthetics, 

the project also allays concerns that a high performance retrofi t 

threatens the character and appeal of a neighborhood.” 

16 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

The 150-year-old Bedford Farmhouse is located in the Building 

America Cold and Very Cold Climate Zone, which necessitates 

significant improvement of the insulation levels. The solution 

for this structure was to seal and insulate the attic and basement 

as conditioned spaces. The attic was unvented, and foil-faced 

polyisocyanurate insulating sheathing was placed on top of the 

existing repaired roof sheathing, while unfaced fi berglass batt 

insulation was placed in the rafters. The resulting R-56 insulation 

contributed to an overall estimated 35% reduction in energy use 

over the Building America benchmark and an estimated annual 

savings of $930. 

Tucson Adobe 

The Building America John Wesley Miller Company renovation 

of a historical adobe home in Tucson (Adobe renovation; http:// 

apps1.eere.energy.gov/buildings/publications/pdfs/building_america/ 

ba_cs_retrofi t_john_wesley_miller.pdf) grappled with a very different 

climate and roof type. Located in the Building America Hot and 

Dry Climate Zone, the home has a traditional flat roof design, 

which required a different solution in energy retrofitting. In this 

case, the original roofing was removed from the flat roof assembly, 

but the framing and plywood sheathing were retained. Two inches 

of polyisocyanurate rigid insulation (R-13) were installed on top of 

the sheathing, followed by a new built-up roof, which was painted 

reflective white for solar reflectance in the hot and sunny climate. 

Florida Victorian 

The Florida Solar Energy Center (FSEC) dealt with the issue 

of historic framing in its restoration case study of the Williams 

home in Cooling Load Reduction and Air Conditioner Design 

in a 19th Century Florida House Museum (Williams House; see 

Chasar [2004] available at www.fsec.ucf.edu/en/publications/pdf/ 

FSEC-CR-1508-05.pdf). One of the project goals was to reduce the 

cooling loads of the house, which necessitated the addition of attic 

insulation. Although spray polyurethane foam products applied to 

the roof deck would have provided both air sealing and insulation, 

it would have hidden part of the historical features of the house and 

the decision was made to add insulation at the ceiling level instead. 

As exemplified by the case studies, roofing solutions for energy 

retrofits will vary with the climate zone, roof construction, and 

historic details of the home. 

(Top) The Building America New Bedford 

Farmhouse case study sealed and insulated 

the attic as a conditioned space, placing 

foil-faced polyisocyanurate on top of the 

existing repaired roof. Building Science 

Corporation. 2010. “Bedford Farmhouse 

High Performance Retrofi t Prototype” 

(Case Study), (www.buildingscience.com), 

Somerville, Massachusetts. 

(Bottom) Blown-in insulation can be used 

to dramatically increase insulation values. 

Another resource for historic 

roof projects is the 1978 NPS 

Preservation Brief 4: Roofi ng for 

Historical Buildings (www.nps.gov/ 

history/hps/tps/briefs/brief04.htm). 

February 28, 2011 17 

17 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

(Top) The Building America Chesapeake 

Habitat for Humanity case study 

demonstrates a solution for brick walls: 

installing rigid insulation between bricks 

and framing, air sealing, and filling the new 

cavity with batts (www.eere.energy.gov/ 

buildings/building_america/mixed_humid_ 

case_studies.html). 

(Middle/Bottom) The Building America 

SEER case study in New Jersey 

demonstrated the use of blownin and foamed insulation under the 

siding (http://apps1.eere.energy.gov/ 

buildings/publications/pdfs/building_ 

america/36474.pdf). 

Walls 

Walls can be sources of air and moisture leaks, and in historical 

homes they may be uninsulated. In addition to air sealing, an 

energy retrofit will seek opportunities for increasing the insulation 

levels of exterior walls. However, insulating walls in historic houses 

can be challenging. 

Chesapeake Habitat for Humanity 

The Building America Chesapeake Habitat for Humanity Baltimore, 

Maryland Case Study (Chesapeake Habitat; http://apps1.eere.energy. 

gov/buildings/publications/pdfs/building_america/ba_cs_retrofi t_ 

chesapeake_habitat.pdf) developed a solution for insulating brickwalled homes. The technical directors on the project—Steven Winter 

Associates—were seeking a solution to the thermal bridging that was 

occurring when framing inside the above-grade walls and fi lling the 

cavities with fiberglass batts. Their R-21 wall solution was to install a 

1/2 inch of rigid insulation between the bricks and stud framing, air 

seal the edges and gaps with foam, and then fill the new interior stud 

wall with R-19 batts. The existing gap between the double brick wall 

allowed for ventilation, so moisture did not penetrate to the foam. 

New Jersey 19th Century 

The Building America Strategies for Energy-Effi cient Remodeling 

2003 retrofit in rural New Jersey (Drumheller and Wiehagen 2004; 

http://apps1.eere.energy.gov/buildings/publications/pdfs/building_ 

america/36474.pdf) demonstrates solutions for a different set of 

issues. In this case, a 19th century home had uninsulated 2x4 walls, 

with wood siding and partial interior sheathing. However, the siding 

had deteriorated and needed to be replaced. The case study shows 

that based on the existing wall conditions, two wall cavity insulation 

choices were available—the use of blown-in insulation materials or 

foam-in-place insulation. Blown-in and foamed insulation materials 

provide more of an opportunity to completely fill irregular wall 

cavities and may be installed through small openings in the framing 

bay. They also are particularly adaptable to insulating wall sections 

that have coverings on both the exterior and interior of the framing 

members. Additional insulation on the exterior of the framing was 

also considered because the siding was being replaced. The Building 

America partners ultimately chose blown and foamed insulation in 

the wall cavity and sheet insulation under the siding. 

Another option for wood-clad buildings is the “drill-and-fi ll” 

method of opening 2-inch holes and injecting fiberglass or cellulose 

insulation into the cavity, resulting in an R-13 to R-21 insulated wall, 

depending on the cavity depth and type of insulation. 

18 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Windows 

The energy audit will have identified moisture and/or air leakage 

around windows and any other problems that exist with the current 

windows. Window treatments may include the following: 

• 	 air sealing, flashing, and weatherstripping 

• 	 repair and reconstruction 

• 	 addition of storm windows 

• 	 replacement with historically accurate replicas 

• 	 replacement with wood windows of similar design (e.g., replacing 

double hung with double hung outfitted with similar material). 

Which option is best suited to the project depends on the results of 

the energy audit, climate, and the project objectives—preservation, 

rehabilitation, or restoration. Because of the highly visible nature 

of windows and their direct bearing on the historical integrity of 

the building, the NTHP promotes rehabilitating existing windows 

whenever possible. If there is water damage to the sills or around 

the window, evaluate whether the window needs resetting with an 

improved drainage plane. 

As noted earlier, it is important to first maximize the inherent 

potential of the house to be energy efficient. Existing awnings or 

shutters that provide appropriate shading, serve to ventilate the 

(Left) Drill-and-fill wall insulation on a 

house located in a Portland, Oregon historic 

district. Typically narrow strips of siding are 

removed before drilling, and sealed holes 

are hidden when siding is reinstalled. 

(Right) Blown-in insulation can be installed 

in walls from the interior. Care must be taken 

to match existing wall fi nish textures. 

The window may not be 

the problem, but the installation 

may be. The Building Science 

Corporation, in Building Science 

Digest-105: Understanding Drainage 

Planes (https://www.buildingscience. 

com/documents/digests/bsd-105­

understanding-drainage-planes/fi les/ 

bsd-105_understanding_drainage_ 

planes.pdf), provides a variety of 

window installation solutions for 

different wall types. 

February 28, 2011 19 

19 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

(Top) The Building America Clark 

Residence retrofit case study demonstrates 

the use of high-quality storm windows 

(www.buildingscience.com) a solution to 

improving window effi ciency. 

(Bottom) An Insulated Glass Unit (IGU) is 

installed as a storm window over stained 

glass. Photo by Bruce Kinzey 

“There is a need to demonstrate there are ways to be 

energy effi cient without 

replacing windows, and that 

historic buildings often have natural 

advantages to ventilate, heat, and 

cool,” said Rock Island Preservation 

Commission Chairman Robert Braun. 

home, and/or are part of the historic character of the house should 

not be removed but maintained in good operating condition. If the 

original design included these features but they are no longer part of 

the structure, consider replacing them in a manner consistent with 

the Secretary’s Standards for the treatment of historic properties 

and guidelines for preserving, rehabilitating, restoring, and 

reconstructing historic houses. 

Massachusetts 1760 Cape 

The Clark Residence retrofi t (www.buildingscience.com/documents/ 

case-studies/cs-ma-ngrid-deep-energy-retrofi t?topic=resources/ 

retrofi ts) demonstrates how a Cape Cod home, circa 1760, can be 

energy efficient and retain a good deal of its historic character. 

The original windows had been replaced with relatively new 

wood-frame windows, but they did not offer suffi cient thermal 

performance and the homeowners were disinclined to replace 

them. Building Science Corporation, a Building America team, 

determined that adding “high quality exterior storm windows 

offered the best combination of improved thermal performance, 

interior condensation control, and exterior rain shielding for 

the windows.” The resulting window specifications included new 

storm windows over existing wood-framed, double-glazed, low-E 

windows. When considering the house as a system, in this case 

there was concern that air-impermeable and vapor-retarding 

insulation, would put the structure at risk because it could no 

longer dry to the inside. To avoid this problem, the renovators 

installed new flashing and made other corrections to the water 

drainage plane to keep the water away from the structure. 

The Color of Glass 

An issue to consider when adding storm windows or replacing 

windows is the color of the glass. Glass color will infl uence the 

quality of light within a building and can also contrast with 

other glass already present or being added to the building. Often, 

operable windows like casements and sliders are replaced and 

storm windows are added to fixed windows. The storm and the 

replacement windows may incorporate glass from different sources 

and appear different if compared side-by-side. The same type of 

comparison may be true when replacement or storm windows 

are installed near windows that are left as-is. Perhaps more 

importantly, tinted glass may obscure existing window features. 

Discuss this issue with the window supplier to ensure the selection 

of consistent glass color, and glass that does not obscure original 

window features. 

20 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Systems for Heating and Cooling a House 

Pasadena Ranch House 

The comprehensive energy audit on the Building America Hartman 

Baldwin Design/Build, Pasadena, California retrofi t (Pasadena; 

http://www1.eere.energy.gov/buildings/building_america/hot_dry_ 

mixed_case_studies.html) provided direction before the team began 

sealing the building shell and installing a new HVAC system. The 

homeowner was surprised to learn that the bottom of the return 

plenum had rusted out and was open to the crawlspace fl oor. 

Not all audits will point to such clear problems, but they will 

provide the information to address the heating and cooling system 

needs. Depending upon the age of the home, it may have a heating 

and cooling system that is very different from most contemporary 

homes—one that may have relied heavily on passive heating or 

cooling, such as shading and cross ventilation from open windows. 

Before installing a new system, ensure that these passive historic 

heating and cooling features have been maximized. Also ensure that 

the recommended energy retrofitting derived from the energy audit 

has been completed. 

If the home has open chases, floor vents, or built-in chimneys 

to provide air flow and ventilation, make sure they are currently 

being used as efficiently as possible. Retain the associated grilles or 

other finishing features for their historical character. Even unused 

radiators may contribute to the historic character of the house, so 

consider retaining them. 

Ceiling fans help with both cooling and heating. Window fans can 

exhaust hot air or bring cool air in overnight. Whole-house fans, 

installed over stairway halls or elsewhere, exhaust hot air that rises 

through the house, while pulling in fresh air from the ground level 

where it is coolest. Ordinary room fans can make a remarkable 

difference in the summer, and the difference in terms of energy use 

can be signifi cant. 

In homes with existing central heating and cooling systems, 

sealing or repairing the existing duct system may reap signifi cant 

benefits. As noted in the Building America Best Practices Guide, 

Air Sealing: A Guide for Contractors to Share with Homeowners, 

all ducts should be sealed, especially in attics, vented crawlspaces, 

and rim areas. In older homes, wall cavities and floor joist cavities 

are sometimes used as return “ducts” to bring air from the return 

registers back to the air-handler unit, but these building cavities are 

The Building America Pasadena Ranch 

House case study demonstrates the 

value of beginning with an energy 

audit. Illustrated here is an open plenum 

discovered in the crawlspace (www.eere. 

energy.gov/buildings/building_america/ 

hot_dry_mixed_case_studies.html). 

All ducts should be sealed, 

especially in attics, vented crawlspaces, 

and rim areas. For more information, 

see Building America’s Air Sealing: 

A Guide for Contractors to Share 

with Homeowners (http://apps1.eere. 

energy.gov/buildings/publications/ 

pdfs/building_america/ba_airsealing_ 

report.pdf). 

February 28, 2011 21 

21 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

This historic home uses Unico’s Small Duct 

High Velocity HVAC equipment, to heat 

and cool the home without modifi cations 

to the original historic structure. 

Photo by Unico 

rarely air sealed and should be replaced with sealed ducts. Refer 

to the aforementioned Building America Best Practices Guide for 

specific guidance on repairing and sealing existing systems (http:// 

apps1.eere.energy.gov/buildings/publications/pdfs/building_america/ 

ba_airsealing_report.pdf). 

Briefly, three situations a renovator may face when replacing a 

system include the need to replace the duct system, replace electric 

resistance or steam heating, or add air cooling. The limitations of 

replacing existing systems, based in part on U.S. Department of 

Energy – Energy Efficiency and Renewable Energy, Energy Savers: 

Limitations When Replacing Existing Heating Systems (www. 

energysavers.gov/your_home/space_heating_cooling/index.cfm/ 

mytopic=12320), are highlighted below: 

• INSTALLING NEW DUCT SYSTEMS. When intending to install 

new duct systems in a historic house, plan the air delivery system 

carefully. It should be efficient without changing the home’s 

historic character by introducing unsightly transoms, dropped 

ceilings, etc. While new homes should always have their furnaces 

and air handlers located in a conditioned space, this is not always 

possible in historic houses. However, if the attic and/or basement/ 

crawlspace have been converted to conditioned space these spaces 

will generally be the best locations for the equipment and ducts. 

In some multi-story homes, however, a different option will be 

needed. High-velocity mini-ducts may provide a solution, because 

they force air through plastic feeder ducts that are only 2 inches 

in diameter. These ducts can be easily threaded through cavities in 

walls, floors, and ceilings. 

A downside of installing mini-ducts is that they generally require 

more outlets (2-inch-diameter round ducts): roughly fi ve outlets 

per ton of cooling, or one outlet for every 2400 Btu of heating. 

These outlets will likely result in higher costs to install the system. 

When installing mini ducts, keep in mind the appearance of the 

house during preliminary planning. Outlets can stand out in a 

room and their placement is very important, especially when 

preserving or restoring a home. Consider putting the outlets in the 

corners of floors and ceilings. 

22 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

•	 REPLACING ELECTRIC RESISTANCE OR STEAM HEATING 

WITH HOT-WATER BASEBOARD HEATING. In homes 

without ducts, replacing electric resistance baseboard heaters or 

steam systems with a hot-water baseboard system can avoid the 

need for new ducts, and may limit the overall cost. Replacing an 

electric resistance system usually will require extensive plumbing, 

but installing it may be less problematic than installing new ducts. 

Converting steam systems to hot water is generally only feasible in 

two-pipe steam systems. 

•	 ADDING AIR COOLING TO A HEATED FORCED-AIR 

(DUCT) SYSTEM AND INSTALLING DUCTS. This can be 

accomplished by adding central air to a forced-air system or 

switching to a heat pump. System sizing should not be done before 

the energy audit has been carried out and all weatherization has 

been completed. While heat pumps typically require larger duct 

systems, duct systems in existing homes are often unnecessarily 

large and rather than being energy efficient, end up wasting energy 

and money. Once the home has been made more efficient the sizing 

may be appropriate. 

Massachusetts Mid-19th Century Farmhouse 

In the case of the Bedford Farmhouse, the retrofi t accomplished 

its goals by insulating the attic and basement to create conditioned 

spaces. The gas furnace was installed in the newly conditioned space, 

and the air handler and distribution system were located entirely 

within conditioned space, using sheet metal trunks and run-outs and 

ducted returns from the upstairs bedrooms. 

Florida Victorian 

The Williams home project faced a different challenge to maximize 

the original design of passive cooling. Because the home was to 

be used as a museum with fixed hours throughout the summer 

months, the decision was made to provide cooling. First, the natural 

system was optimized, reducing the amount of humidity and dry 

air loss through air sealing, insulation, and shading/refl ectivity. The 

builder used the high-velocity mini-duct distribution system, citing 

two advantages in its situation—because the outlets are smaller, 

they are less noticeable, and the delivered air temperature is colder 

than conventional systems, which improves the dehumidifi cation 

properties of the cooled air. Dehumidification was important—as 

the builder energy-retrofit the home and added air conditioning it 

changed the system, affecting the way temperatures and humidity 

moved through the building and building envelope. 

Building America’s Bedford 

Farmhouse High-Performance 

Retrofi t Prototype accomplished 

its retrofitting goals by locating the gas 

furnace in the conditioned attic and 

locating the air-handler and distribution 

systems within conditioned space 

(for more information, see 

www.buildingscience.com/documents/ 

case-studies/cold-climate-bedfordfarmhouse-retrofi t-case-study). 

The Williams home project 

—Cooling Load Reduction and Air 

Conditioner Design in a 19th Century 

Florida House Museum—optimized the 

home’s natural system and installed a 

high-velocity, mini-duct distribution 

system (for more information, see 

www.fsec.ucf.edu/en/publications/pdf/ 

FSEC-CR-1508-05.pdf). 

February 28, 2011 23 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

When retrofitting with can lights, make 

sure they are insulation-contact air tight 

(ICAT) and labeled as meeting ASTM E283 

when tested at 1.57 psf (75 Pa) pressure 

differential with no more than 2.0 cfm of 

air movement and sealed with a gasket 

or caulk between the housing and interior 

wall or ceiling covering. 

Lighting Options 

Incandescent lighting has traditionally 

delivered about 85% of household illumination. Incandescent lamps operate without a 

ballast, are dimmable and instantly controllable, and light up instantly. Most familiar are 

the standard pear-shaped, screw-in “A”-type 

incandescent light bulbs. They produce a 

warm light and provide excellent color quality. They have a low efficacy compared to all 

other lighting options (10 to 17 lumens per 

watt) and a short average operating life (750 

to 2500 hours). 

Fluorescent lamps use 25% to 35% of 

the energy used by incandescent lamps 

to provide the same amount of illumination (efficacy of 100 lumens per watt) 

and last about 10 times longer (7,000 to 

24,000 hours). Improvements in technology have resulted in fluorescent lamps with 

color temperature and color rendition that 

are comparable to incandescent lamps. 

LED lights use 35% to 50% of the energy 

used by an incandescent lamp to provide 

the same amount of illumination (luminaire 

efficacy of about 70 lumens per watt) and 

last longer than incandescent or fl uorescent 

bulbs. (Good-quality white LEDs in welldesigned fixtures are expected to have a 

useful life of 30,000 to 50,000 hours.) LED 

device efficacy doesn’t tell the whole story. 

Good LED system and luminaire design is 

imperative to energy-effi cient LED lighting 

fixtures. For example, a replacement LED 

downlight combines thermal management 

and optical design to produce up to 700 

lumens using only 6 to 7 watts. 

Citation: from LED Basics: What retailers, energy effi ciency 

advocates, and consumers need to know to make informed 

buying decisions (2 pages, November 2009; www.eere. 

energy.gov/buildings/ssl/factsheets.html). 

Lighting 

Artificial lighting consumes almost 15% of household electricity, 

and significant energy savings can be achieved by retrofi tting a 

home’s lighting. Note that older homes started out with no lighting 

or gas lighting and have already been modified at least once. Use 

of new lighting technologies can reduce lighting energy use in 

homes by 50% to 75%. Advances in lighting controls offer further 

energy savings by reducing the amount of time lights are on but 

not serving a useful purpose. Advanced lighting controls also offer 

a new amenity—lights that come on automatically when they are 

needed (http://apps1.eere.energy.gov/buildings/publications/pdfs/ 

building_america/26467.pdf). 

Unlike other energy-retrofitting techniques, lighting changes have 

fewer impacts on other house systems; the biggest impact is on 

reducing the cooling load in summer. New compact fl uorescent 

lamps can be found for many socket styles and sizes. Their use will 

reduce the heating load and the energy budget of the home. Consider 

installing and using task lighting and LED applications that will 

enhance the feel of the room. LEDs are particularly appropriate 

for downlighting, under-cabinet lighting, and specific task lighting. 

Furthermore, use of a wide range of sensor light fixtures on the 

market, if used properly, will help to conserve energy. 

Existing light fixtures are an important element of a historic house 

whether or not they are functional. For example, unused gas light 

fixtures can be retained as historic elements of decor. 

Finally, careful trimming of exterior landscaping elements that 

detract from the natural interior lighting also should be considered 

to improve lighting in the home. 

Solid-State Lighting Research: 

Solid-state lighting technologies are changing and improving rapidly, and 

products arriving on the market exhibit a wide range of performance. 

The DOE Commercially Available LED Product Evaluation and Reporting 

(CALiPER) program provides reliable unbiased product performance 

information (www.eere.energy.gov/buildings/ssl/caliper.html). 

24 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Other Considerations During an Energy Retrofi t 

Several retrofitting options won’t necessarily be the focus of the 

energy audit, but they should be considered in an energy retrofi t, 

e.g., porches, landscaping, and seismic retrofi ts 

Porches 

Porches should not be ignored when considering ways to make 

a home more energy effi cient; efficiencies can be gained from 

insulating and air sealing points where porch roofs intersect house 

walls. Before adding insulation, make sure the drainage plane is not 

allowing water to run between the porch and house, or within the 

porch roof structure. 

There are also simple ways of making a porch a more temperate and 

attractive place to spend time. For example, installing an awning or 

planting shade trees can transform the space. Adding a ceiling can 

keep the heat from bearing down on occupants. Installing a ceiling 

fan can ensure air movement, without detracting from the general 

feel and historical quality of the porch. 

Originally designed for shade and shelter from the elements and 

outdoor living area, porches are sometimes walled in and fi nished to 

provide additional interior space. Doing this may detract from the 

flow of spaces within the home and change its historic character. If 

additional interior space is needed, consider adding it where it will 

have less of an impact on the historic image that the home presents 

to the street. If a glassed-in front porch already exists, consider 

returning it to its original configuration. This will enhance the 

historic character of the house while providing an attractive, shaded 

outdoor space. 

Landscaping and Siting 

If the property landscaping has been maintained over the life of 

the home, it will likely include trees and other features that are 

aesthetically compatible with the home and provide shade and wind 

breaks. Historic landscape features may also include valuable or 

even irreplaceable plant material, such as mature trees and fl owering 

shrubs that would take many decades to replicate. Before removing 

historic plantings, consider that they are there for a reason and they 

are part of the home’s historic character. 

The Building America Tucson Adobe case 

study retained the historic landscaping 

with plants and ground cover that require 

minimum irrigation (www.eere.energy. 

gov/buildings/building_america/hot_dry_ 

mixed_case_studies.html). 

February 28, 2011 25 

25 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Landscaping 

Significant changes in grade or material can alter drainage patterns 

and create moisture problems that did not previously exist. If historic 

landscaping might cause damage to the home or has grown to the 

point where natural lighting is blocked, consider contacting a tree 

surgeon. By removing a weak limb, trimming back some overgrown 

branches, or thinning branches, you can save the appearance of the 

home, and retain the value of the historic landscaping. 

Also note that if the house is located in a historic district, landscape 

guidelines may dictate style, plant use, or use of hardscape features. 

Seismic Retrofi ts 

Preserving the historic features of a home when performing a seismic 

retrofit, typically for structural stabilization, can create a particular 

challenge. Recognizing how critical structural stabilization can 

damage the historic value of buildings, the National Park Service 

has developed related guidance in Preservation Brief 41, The Seismic 

Retrofit of Historic Buildings Keeping Preservation in the Forefront 

(www.nps.gov/history/hps/tps/briefs/brief41.htm). The Brief 

identifies three keys to successfully interfacing historic preservation 

with a seismic retrofi t: 

•	 PRESERVE AND RETAIN historic materials to the greatest 

extent possible and do not replace them wholesale in the process 

of seismic strengthening. 

•	 RESPECT THE CHARACTER AND INTEGRITY of the historic 

building and make them visually compatible with its design 

whether installing hidden or exposed new seismic retrofi t systems. 

•	 MAKE SEISMIC WORK “REVERSIBLE” to the greatest extent 

possible to allow its removal for future use of improved systems 

and traditional repair of remaining historic materials. 

26 February 28, 2011 
ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

5. Conclusion 

As indicated in Chapter 4, renovation efforts, including energy-effi ciency 

improvements, can have broad impacts on the home. In addition to 

changes in the whole-house system that may occur during a retrofi t, care 

must be taken to avoid changing any of the following original design 

elements that might affect the historic character of the home: 

• 	 roof profile and materials 

• 	 windows 

• 	 porches 

• 	 special period architectural features 

• 	 interior finishes and trims 

• 	 landscape features 

• 	 equipment (visible features, such as lighting fi xtures, heating 

registers, ductwork, vents and stacks). 

Once the home energy audit and inspection identify the recommended 

retrofitting needs of a home, balancing them with historic preservation 

needs can seem overwhelming. Luckily, numerous resources are 

available to the building contractor and homeowner alike to inform 

and ease the process. For example, the National Trust for Historic 

Preservation also provides leadership, education, advocacy, and 

resources to save America’s diverse historic places and revitalize its 

communities. The National Institute of Building Sciences through 

its Whole Building Design Guide (www.wbdg.org/) offers a one-stop 

shop for building-related guidance, criteria, and technologies from 

the whole-building perspective, as well. And closest to home, local 

design guides provide guidance specific to local climate conditions 

and architectural considerations. Building America continues to work 

with research teams and these agencies to provide research results for 

whole-house energy-effi cient retrofi ts. 

Investing money and time in retrofitting older homes in a way 

that respects their historic character can promote environmental 

conservation and preservation both. Use the resources cited herein 

and recommended practices derived from Building America’s 

renovation case studies and series of best practices guides. 

Inform yourself and plan your integrated approach to building 

and renovating historic homes. To achieve energy-effi cient, highperformance dwellings, build upon the inherent durability of 

the existing home and preserve its historic character, while also 

improving its indoor air quality and enhancing the health, safety, 

and comfort of its occupants. 

February 28, 2011 27 

27 
 

 

 

 

ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

References 

American Society for Heating, Refrigerating, and Air 

Conditioning Engineers, Inc. (ASHRAE). 2007. Ventilation 

for Acceptable Indoor Quality. ASHRAE Standard 62.1, 

Atlanta, Georgia. 

Building Performance Institute, Inc. (BPI). Homepage: 


Comfort, Health, Safety, Durability, Energy Effi ciency.
 

Available at: www.BPI.org
 

Building Science.com, Building Science Information. 


Designs That Work. Cold Climate: Bedford Farmhouse 


High Performance Retrofit Prototype, by Building Science 


Corporation (4/26/2010). Available at: www.buildingscience.
 

com/documents/case-studies/cold-climate-bedford-farmhouseretrofi t-case-study)
 

Building Science.com, Building Science Information. 


Designs That Work. Cold Climate: National Grid Deep Energy 


Retrofit Pilot Program—Clark Residence, by Building Science 


Corporation (3/30/2010). Available at: www.buildingscience.
 

com/documents/case-studies/cs-ma-ngrid-deep-energyretrofi t?topic=resources/retrofi ts
 

www.buildingscience.com/documents/
 

digests/bsd-105-understanding-drainageplanes/?searchterm=understanding%20drainage%20planes
 

Chasar, D. 2004. Cooling Load Reduction and Air Conditioner 


Design in a 19th Century Florida House Museum. Florida Solar 


Energy Center/University of Central Florida, Cocoa Florida. 


Available at: www.fsec.ucf.edu/en/publications/pdf/FSECCR-1508-05.pdf
 

City of Eureka (California) Community Development 

Department. Permits and Forms. Available at: 

www.ci.eureka.ca.gov/depts/cd/permits_n_forms.asp 

Colorado Preservation, Inc. “What hazardous materials should 

I be concerned about in my building?” under FAQs. Available at: 

www.coloradopreservation.org/faqs.html#05 

Drumheller, S.C. and J. Wiehagen. 2004. Strategies for EnergyEfficient Remodeling: SEER 2003 Case Study Report. NREL/ 

SR-550-36474, National Renewable Energy Laboratory, Golden, 

Colorado. Available at: http://apps1.eere.energy.gov/buildings/ 

publications/pdfs/building_america/36474.pdf 

Historic Building Inspectors Association. Homepage: 

http://inspecthistoric.org/ 

National Conference of State Historic Preservation Offi cers. 

“State Information and SHPO List” under Find a SHPO. 

Available at: www.ncshpo.org/fi nd/index.htm#top 

National Institute of Building Sciences. “Design Guidance: Apply 

the Preservation Process Successfully in Whole Building Design 

Guide. Available at: www.wbdg.org/design/apply_process.php 

National Institute of Building Sciences. Whole Building Design 

Guide. Homepage: www.wbdg.org 

National Trust for Historic Preservation. 

See: www.preservationnation.org/ 

National Trust for Historic Preservation. Start with 

the Roof, A Guide for Keeping Weather Tight. Available at: 

www.preservationnation.org/issues/weatherization/roofi ng/ 

additional-resources/nthp_roofi ng.pdf 

U.S. Department of Energy (DOE), Building America. Efficient 

Solutions for Existing Homes, Case Study: HartmanBaldwin 

Design/Build, Pasadena, CA. Available at: http://search.nrel. 

gov/cs.html?url=http%3A//apps1.eere.energy.gov/buildings/ 

publications/pdfs/building_america/ba_cs_retrofi t_hartman_ 

baldwin.pdf&charset=utf-8&qt=url%3Aeere.energy.gov/ 

buildings/building_america/+url%3Apublications/pdfs/ 

building_america/+%7C%7C+hartman+baldwin+design/&col=er 

en&n=1&la=en 

U.S. Department of Energy (DOE), Building America. Efficient 

Solutions for Existing Homes, Comprehensive Energy Retrofi t, 

Case Study: Asdal Builders, LCC, Pittsburgh, PA. Available at: 

http://apps1.eere.energy.gov/buildings/publications/pdfs/ 

building_america/ba_cs_retrofi t_asdal_builders.pdf 

U.S. Department of Energy (DOE), Building America. 

Efficient Solutions for Existing Homes, Comprehensive Energy 

Retrofit, Case Study: Chesapeake Habitat for Humanity, 

Baltimore, MD. Available at: http://apps1.eere.energy.gov/ 

buildings/publications/pdfs/building_america/ba_cs_retrofi t_ 

chesapeake_habitat.pdf 

U.S. Department of Energy (DOE), Building America. Efficient 

Solutions for Existing Homes, Comprehensive Energy Retrofi t, 

Case Study: Habitat for Humanity, Newburgh, NY. Available 

at: http://apps1.eere.energy.gov/buildings/publications/pdfs/ 

building_america/ba_cs_retrofi t_newburgh_habitat.pdf 

U.S. Department of Energy (DOE), Building America. 

Efficient Solutions for Existing Homes, Comprehensive Energy 

Retrofit, Case Study: John Wesley Miller Companies, Tucson, 

AZ. Available at: http://apps1.eere.energy.gov/buildings/ 

publications/pdfs/building_america/ba_cs_retrofi t_john_ 

wesley_miller.pdf 

U.S. Department of Energy (DOE), Office of Energy Effi ciency & 

Renewable Energy (EERE). “Home Energy Assessments” under 

Energy Savers. Available at: www.energysavers.gov/your_home/ 

energy_audits/index.cfm/mytopic=11160 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE). “Limitations When Replacing 

Existing Heating Systems” under Energy Savers, Space Heating 

& Cooling, System Selection & Replacement, Replacement 

Limitations. Available at: www.energysavers.gov/your_home/ 

space_heating_cooling/index.cfm/mytopic=12320 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE), Building Technologies Program. 

“Technology Fact Sheet: Efficient Lighting Strategies.” Available 

at http://apps1.eere.energy.gov/buildings/publications/pdfs/ 

building_america/26467.pdf 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE). “Technology Fact Sheets” under 

Solid State Lighting, Information Resources. Available at: 

www.eere.energy.gov/buildings/ssl/factsheets.html 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE), Building Technologies Program. 

“About Building America” under Building America. Available at: 

www.buildingamerica.gov 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE), Building Technologies Program. 

“Climate-Specific Publications” under Building America. 

Available at: www.eere.energy.gov/buildings/building_america/ 

climate_specifi c_publications.html 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE), Building Technologies Program. 

“Research Projects” under Program Areas, Building America. 

Available at: http://apps1.eere.energy.gov/buildings/building_ 

america/cfm/project_locations.cfm 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE), Building Technologies Program. 

2010. Retrofit Techniques & Technologies: Air Sealing, A Guide 

for Contractors to Share with Homeowners, Volume 10, Building 

America Best Practices Series. Available at: http://apps1.eere. 

energy.gov/buildings/publications/pdfs/building_america/ 

ba_airsealing_report.pdf 

U.S. Department of Energy (DOE), Office of Energy Effi ciency 

& Renewable Energy (EERE), Building Technologies Program. 

“Technology Fact Sheet: Efficient Lighting Strategies.” Available 

at: www.ornl.gov/sci/roofs+walls/insulation/ins_05.html 

U.S. Department of the Interior (DOI), National Park Service 

(NPS), National Register Publications. “II. National Register 

Criteria for Evaluation” in National Register Bulletin How to 

Apply the National Register Criteria for Evaluation. Available at: 

www.nps.gov/nr/publications/bulletins/nrb15/nrb15_2.htm 

U.S. Department of the Interior, National Park Service, National 

Register Publications. National Register Bulletin How to Apply 

the National Register Criteria for Evaluation. Available at: 

www.nps.gov/nr/publications/bulletins/nrb15 

U.S. Department of the Interior (DOI), National Park Service 

(NPS), Technical Preservation Services. “Roofing for Historic 

Buildings” in 4 Preservation Briefs. Available at: 

www.nps.gov/history/hps/tps/briefs/brief04.htm 

U.S. Department of the Interior (DOI), National Park Service 

(NPS). “The Historical Model? ‘Chrisfield’” under Fitting Your 

Work to Time + Place. Available at: www.nps.gov/history/hps/ 

workingonthepast/chrisfi eld.htm 

U.S. Department of the Interior (DOI), National Park Service 

(NPS), Technical Preservation Services. “The Secretary of the 

Interior’s Standards for the Treatment of Historic Properties” 

under Standards and Guidelines. Available at: 

www.nps.gov/history/hps/tps/standards_guidelines.htm 

U.S. Department of the Interior (DOI), National Park Service 

(NPS), Technical Preservation Services. “The Seismic Retrofi t of 

Historic Buildings – Keeping Preservation in the Forefront” in 41 

Preservation Briefs. Available at: www.nps.gov/history/hps/tps/ 

briefs/brief41.htm 

U.S. Environmental Protection Agency (EPA). “Asbestos in 

Products and Buildings and How to Manage It” under Asbestos. 

Available at: www.epa.gov/asbestos/pubs/pubs.html 

U.S. Environmental Protection Agency (EPA). “Renovation, 

Repair and Painting (RRP)” under Lead. Available at: 

www.epa.gov/lead/pubs/renovation.htm 

U.S. Environmental Protection Agency (EPA), Brownsfi eld 

Sustainability Pilots Program. Sustainable Solutions for Historic 

Houses in Northern California, A Voluntary Green Code & Green 

Rehabilitation Manual. Available at: www.epa.gov/brownfi elds/ 

sustain_plts/reports/green_home_guide_fi nal.pdf 

Federal Preservation Institute. Historic Preservation Learning 

Portal. www.historicpreservation.gov/web/guest/2 

National Trust for Historic Preservation. Historically Useful: 

Cold Climate Features. www.preservationnation.org/issues/ 

weatherization/historically-useful-cold-climate.html 

National Trust for Historic Preservation. Weatherization Guide 

for Older & Historic Buildings. www.preservationnation.org/ 

issues/weatherization 

U.S. Department of Energy and the Nebraska Energy Offi ce. 

Energy Efficiency and Historic Preservation: A Planning Guide 

for Buildings. 2001. www.neo.ne.gov/rebuildbook.pdf 

February 28, 2011 29 

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ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

Appendix — Health and Safety Concerns 

Contractors need to keep safety and health at the forefront of any retrofitting job, because some health and 

safety issues can result in death and huge costs, and they need to be considered when planning the project. 

The type of health and safety concerns encountered will depend upon the age and condition of the home and 

the type of project being undertaken. This section identifies some of the issues to be aware of and associated 

resources for further information. 

The problems encountered in historic buildings include asbestos, lead, animal matter, radon, and underground 

storage tanks. Colorado Preservation, Inc., a private nonprofit, statewide historic preservation organization, 

provides a solid outline of health and safety concerns (www.coloradopreservation.org/faqs.html#05). 

• ASBESTOS. Commonly present in historic buildings built or renovated after 1870, asbestos may be found 

in insulation, roofing materials, wallboard, flooring, chimneys, paint, plaster, wallpaper, exterior sheathing, 

and more. As a material used widely and in a multitude of applications, it is wise to assume that asbestos is 

present in your building. Mesothelioma is a lung cancer that may be caused by inhaling asbestos fi bers. 

(See the Whole Building Design Guide, a program of the National Institute of Building Sciences, at 

www.wbdg.org/design/apply_process.php.) 

According to the U.S. Environmental Protection Agency (EPA), one of the most common places to fi nd 

asbestos is in deteriorating, damaged, or disturbed asbestos-containing products such as insulation, 

fi reproofing, acoustical materials, and floor tiles. Asbestos siding is also a significant concern for home 

renovators. The EPA website provides information about managing and removing asbestos, which are best 

done by professionals (see www.epa.gov/asbestos/pubs/pubs.html). Each state has training and accreditation 

services that will help you find a qualified, trained, and accredited professional. 

• LEAD. Lead was used extensively in paint until the mid-1900s, and was outlawed for use in residential 

construction in 1978. As renovation activities disturb surfaces bearing lead-based paints, chips and 

lead-bearing dust may be ingested or inhaled, posing a significant health risk. Lead is also found in 

solder, roofing metals, piping, and other materials because of its waterproofing quality. (See the Historical 

Chrisfield Model at www.nps.gov/history/hps/workingonthepast/chrisfi eld.htm.) 

The National Trust for Historic Preservation provides guidance on working with lead paint and addresses 

the EPA’s regulations—known as the renovation, repair, and painting rule—which went into effect in April 

2010. Under the new rule, contractors “performing renovation, repair and painting projects that disturb 

lead-based paint in homes...built before 1978 must be certified and must follow specific work practices to 

prevent lead contamination.” The EPA provides extensive guidance in working with lead (see www.epa.gov/ 

lead/pubs/renovation.htm), and information to contact your local state agency for that can provide local 

information regarding certification and guidance in finding appropriately trained professionals. 

30 February 28, 2011 
 

 

 

 

ENERGY PERFORMANCE TECHNIQUES AND TECHNOLOGIES PRESERVING HISTORIC HOMES
 

• ANIMAL MATTER. Animal matter is present in the form of animal excrement, including rodent 

droppings, urine, and bat and pigeon guano, and feathers. Hantavirus is carried by rodent material and 

passed on to humans by inhaling airborne particles. Ornithosis, also known as psittacosis, may be harbored 

in guano and carried by airborne particles into the respiratory system (for more information, see 

www.coloradopreservation.org/faqs.html#05). 

Care must be taken to protect workers from inhaling contaminated particles, and the skin should be kept 

covered. Wear dust masks, goggles, and rubber gloves. Wash skin and clothing with disinfectant soap after 

each contact with potentially contaminated material. 

Homes that have been unoccupied or otherwise uncared for may have rodents, nests, or their droppings in 

insulation, duct runs, or air-handling equipment. Professional duct vacuuming can remove the problem 

from both the air handler and ducts, which would otherwise spread the potential contaminants through 

the house. For details about cleanup and working in a contaminated environment, contact your local 

public health department. 

• RADON. Radon is a radioactive gas produced by the decay of radium. It is harmful when inhaled and 

is a known cause of lung cancer. It may accumulate in basements and crawlspaces and where ventilation 

is poor (see www.coloradopreservation.org/faqs.html#05). 

Radon is a localized concern, and your building department can tell you if it is a concern in your 

community. Test kits are available at hardware stores, or you may contact an environmental contractor 

for more extensive testing. 

• UNDERGROUND STORAGE TANKS. Homes with oil heat or other fuel-storage needs may have 

underground storage tanks leaking and causing soil and potential groundwater contamination. 

Underground storage tanks may have been identified in disclosure statements at the last sale and purchase 

of the home, or they may be completely undocumented. Contact your building department for permitting 

history or the local historic district for information about the home; information may be available to 

determine if there is a tank onsite. Your state’s department of environmental quality should provide 

guidance appropriate to local issues and soils. 

• COMBUSTION SAFETY. Combustion appliances that draw their combustion air from the room in which 

they are located are called atmospheric vented or natural-draft combustion appliances. These appliances 

(which could include furnaces, water heaters, clothes dryers, wood stoves, and gas stoves) may have the 

potential to back draft under the right conditions. Combustion appliances should be tested for backdrafting 

before and after any other home weatherization work such as air sealing and insulating is completed. Ideally, 

older natural-draft combustion appliances would be replaced with higher-efficiency sealed combustion, 

induced draft, or power-vented appliances. Non-combusting appliances (for example heat pumps) are 

another safe option. Gas lines should also be checked for leaks. Homes with combustion appliances should 

have carbon monoxide detectors that meet UL 2034. See Building America’s Air Sealing guide for more 

information www.eere.energy.gov/library. 

February 28, 2011 31 

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Visit our Web sites at:
 

R

www.buildingamerica.gov 

www.pathnet.org 

www.energystar.gov 

Building America Program 

George S. James • New Construction • 202-586-9472 • fax: 202-586-8134 • e-mail: George.James@ee.doe.gov 

Building America Program • Office 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) 

Philip Fairey • Florida Solar Energy Center • 1679 Clearlake Road • Cocoa, FL 32922 • 321-638-1005 • 

fax: 321-638-1439 • e-mail: pfairey@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 

Pacific Northwest National Laboratory 

Michael Baechler • 620 SW 5th, Suite 810 • Portland, OR 97204 • 503-417-7553 • fax: 503-417-2175 • 

e-mail: michael.baechler@pnl.gov • www.pnl.gov 

Produced for the U.S. Department of Energy (DOE) by Pacific Northwest National Laboratory, 

Contract DE-AC05-76RLO 1830. 

Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste. 

EERE Information Center For information on Building America 

1-877-EERE-INFO (1-877-337-3463) visit www.buildingamerica.gov. 

www.eere.energy.gov/informationcenter The website contains expanded 

case studies, technical reports, and 

PNNL 20185 February 28, 2011 best practices guides.