2015 IECC 

Revised by the Manufactured Housing Working Group

October 28, 2014

Overview:

This document outlines the changes to the residential sections of the 2015 International Energy 

Conservation Code (IECC) discussed by the manufactured housing (MH) working group (WG). 

Each section is marked with a note indicating the consensus action agreed to by the WG. The 

notes are listed and defined in Table 1 below.

Table 1 Notation Descriptions

Notation Description

Deleted by WG Indicates the WG reached consensus that the section is not applicable to MH.

Included by WG Indicates the WG reached consensus that the section is applicable to MH and 

required no revisions.

Revised the WG Indicates the WG reached consensus that the section is applicable to MH but 

required revisions.

Added by WG Indicates the WG reached consensus on adding a new section.

Deferred to DOE by 

WG

Indicates the WG reached consensus that the section should be addressed by 

DOE in the Notice of Proposed Rulemaking (NOPR).

Included in Concept 

by WG

Indicates the WG reached consensus on the conceptual nature of the section. 

DOE will need to revise the exact text and consider impacts of other provisions 

of the term sheet when developing the NOPR.

Not Discussed by WG Indicates the WG did not discuss or reach consensus on the action for a 

section. DOE will need to determine how to address these sections in the 

NOPR.

Deleted – Term Sheet 

Supersedes

Indicates sections that were directly superseded by items in the term sheet.
IECC—RESIDENTIAL PROVISIONS

TABLE OF CONTENTS

CHAPTER 1 SCOPE AND ADMINISTRATION . . . . . . . . . . . . . R-3

PART 1—SCOPE AND APPLICATION. . . . . . . . . . . R-3

Section

R101 Scope and General Requirements. . . . . . . . . . . . R-3

R102 Alternative Materials, Design and Methods of Construction and Equipment. . . . R-3

PART 2—ADMINISTRATION AND ENFORCEMENT . . . . . . . . . . . . . . . . . . . . . R-3

R103 Construction Documents . . . . . . . . . . . . . . . . . . R-3

R104 Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-4

R105 Validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-5

R106 Referenced Standards . . . . . . . . . . . . . . . . . . . . . R-5

R107 Fees. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-5

R108 Stop Work Order . . . . . . . . . . . . . . . . . . . . . . . . R-5

R109 Board of Appeals . . . . . . . . . . . . . . . . . . . . . . . . R-5

CHAPTER 2 DEFINITIONS . . . . . . . . . . . . . . . . . . R-7

Section

R201 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-7

R202 General Definitions . . . . . . . . . . . . . . . . . . . . . . R-7

CHAPTER 3 GENERAL REQUIREMENTS . . . .R-11

Section

R301 Climate Zones. . . . . . . . . . . . . . . . . . . . . . . . . . R-11

R302 Design Conditions . . . . . . . . . . . . . . . . . . . . . . R-26

R303 Materials, Systems and Equipment . . . . . . . . . R-26

CHAPTER 4 RESIDENTIAL ENERGY

EFFICIENCY . . . . . . . . . . . . . . . . . . R-29

Section

R401 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-29

R402 Building Thermal Envelope . . . . . . . . . . . . . . . R-29

R403 Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-35

R404 Electrical Power and Lighting Systems . . . . . . R-37

R405 Simulated Performance Alternative (Performance). . . . . . . . . . . . . . . . . . . . . . . . R-37

R406 Energy Rating Index Compliance

Alternative . . . . . . . . . . . . . . . . . . . . . . . . . . R-41

CHAPTER 5 EXISTING BUILDINGS. . . . . . . . . R-43

Section

R501 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-43

R502 Additions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-43

R503 Alterations . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-44

R504 Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-44

R505 Change of Occupancy or Use. . . . . . . . . . . . . . R-44

CHAPTER 6 REFERENCED STANDARDS. . . . R-45

APPENDIX RA RECOMMENDED PROCEDURE FOR WORST-CASE TESTING OF ATMOSPHERIC 

VENTING SYSTEMS UNDER R402.4 OR R405 CONDITIONS 5ACH50 . . . R-49

Section

RA101 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-49

RA201 General Definitions . . . . . . . . . . . . . . . . . . . . . R-49

RA301 Testing Procedure . . . . . . . . . . . . . . . . . . . . . . R-49

APPENDIX RB SOLAR-READY PROVISIONS—DETACHED ONE- AND TWOFAMILY DWELLINGS,

MULTIPLE SINGLE-FAMILY DWELLINGS (TOWNHOUSES). . R-51

Section

RB101 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-51

RB102 General Definitions . . . . . . . . . . . . . . . . . . . . . R-51

RB103 Solar-ready Zone . . . . . . . . . . . . . . . . . . . . . . . R-51

INDEX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-53

CHAPTER 1 [RE] [Deleted by WG]

CHAPTER 2 [RE] DEFINITIONS

R201.1 Scope. [Revised by WG] Unless stated otherwise, the following definitions are applicable to the Term 

Sheet.

R201.2 Interchangeability. [Included by WG] Words used in the present tense include the future; words in the 

masculine gender include the feminine and neuter; the singular number includes the plural and the plural includes 

the singular. 

R201.3 Terms defined in other codes. [Deleted by WG]

R201.4 Terms not defined. [Included by WG] Terms not defined by this chapter shall have ordinarily accepted 

meanings such as the context implies. 

SECTION R202 GENERAL DEFINITIONS 

ABOVE-GRADE WALL. [Deleted by WG]

ACCESSIBLE. [Revised by WG] Admitting close approach as a result of not being guarded by locked doors, 

elevation or other effective means 

ADDITION. [Deleted by WG]

AIR BARRIER. [Included by WG] Material(s) assembled and joined together to provide a barrier to air leakage 

through the building envelope. An air barrier may be a single material or a combination of materials. 

ALTERATION. [Deleted by WG]

APPROVED. [Deleted by WG]

APPROVED AGENCY. [Deleted by WG]

AUTOMATIC. Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for 

example, a change in current strength, pressure, temperature or mechanical configuration (see “Manual”). 

BASEMENT WALL. [Deleted by WG]

BUILDING. [Deleted by WG] 

BUILDING SITE. [Deleted by WG]

BUILDING THERMAL ENVELOPE. [Revised by WG] Exterior walls, floor, roof and any other building elements that enclose conditioned space or provide a boundary between conditioned space and exempt or 

unconditioned space. 

C-FACTOR (THERMAL CONDUCTANCE). [Included by WG] The coefficient of heat transmission (surface 

to surface) through a building component or assembly, equal to the time rate of heat flow per unit area and the unit 

temperature difference between the warm side and cold side surfaces (Btu/h ·ft

2 

·°F) [W/(m2 ·K)]. 

CIRCULATING HOT WATER SYSTEM. [Included by WG] A specifically designed water distribution system 

where one or more pumps are operated in the service hot water piping to circulate heated water from the waterheating equipment to fixtures and back to the water-heating equipment. 

CLIMATE ZONE. [Included by WG] A geographical region based on climatic criteria as specified in this code. 

CODE OFFICIAL. [Deleted by WG] 

COMMERCIAL BUILDING. [Deleted by WG]

CONDITIONED FLOOR AREA. [Included by WG] The horizontal projection of the floors associated with the 

conditioned space. 

CONDITIONED SPACE. [Included by WG] An area, room or space that is enclosed within the building thermal 

envelope and that is directly or indirectly heated or cooled. Spaces are indirectly heated or cooled where they 

communicate through openings with conditioned spaces, where they are separated from conditioned spaces by 

uninsulated walls, floors or ceilings, or where they contain uninsulated ducts, piping or other sources of heating or 

cooling. 
CONTINUOUS AIR BARRIER. [Revised by WG] A combination of materials and assemblies that restrict or 

prevent the passage of air through the building thermal envelope.

CONTINUOUS INSULATION (ci). [Included by WG] Insulating material that is continuous across all structural 

members without thermal bridges other than fasteners and service openings. It is installed on the interior or exterior, 

or is integral to any opaque surface, of the building envelope. 

CRAWL SPACE WALL. [Included by WG] The opaque portion of a wall that encloses a crawl space and is 

partially or totally below grade. 

CURTAIN WALL. [Deleted by WG] 

DEMAND RECIRCULATION WATER SYSTEM. [Included by WG] A water distribution system where 

pump(s) prime the service hot water piping with heated water upon demand for hot water. 

DOE. U.S. Department of Energy

DUCT. [Included by WG] A tube or conduit utilized for conveying air. The air passages of self-contained systems 

are not to be construed as air ducts. 

DUCT SYSTEM. [Included by WG] A continuous passageway for the transmission of air that, in addition to 

ducts, includes duct fittings, dampers, plenums, fans and accessory air-handling equipment and appliances. 

DWELLING UNIT. [Deleted by WG]ENERGY ANALYSIS. [Included by WG] A method for estimating the 

annual energy use of the proposed design and standard reference design based on estimates of energy use. 

ENERGY COST. [Included by WG] The total estimated annual cost for purchased energy for the building 

functions regulated by this code, including applicable demand charges. 

ENERGY SIMULATION TOOL. [Revised by WG] A DOE approved software program or calculation-based 

methodology that projects the annual energy use of a building. 

ERI REFERENCE DESIGN. [Deleted by WG]

EXTERIOR WALL. [Revised by WG] Walls that enclose conditioned space.

FENESTRATION. [Included by WG] Products classified as either vertical fenestration or skylights. 

FENESTRATION PRODUCT, SITE-BUILT. [Deleted by WG]

F-FACTOR. [Deleted by WG]

HEATED SLAB. [Deleted by WG]

HIGH-EFFICACY LAMPS. [Revised by WG] Compact fluorescent lamps, T-8 or smaller diameter linear 

fluorescent lamps, or lamps with a minimum efficacy of: 

1 60 lumens per watt for lamps over 40 watts; 

2 50 lumens per watt for lamps over 15 watts to 40 watts; and 

3. 40 lumens per watt for lamps 15 watts or less. 

HISTORIC BUILDING. [Deleted by WG]

INFILTRATION. [Included by WG] The uncontrolled inward air leakage into a building caused by the pressure 

effects of wind or the effect of differences in the indoor and outdoor air density or both. 

INSULATED SIDING. [Included by WG] A type of continuous insulation with manufacturer-installed insulating 

material as an integral part of the cladding product having a minimum R-value of R-2. 

INSULATING SHEATHING. [Included by WG] An insulating board with a core material having a minimum Rvalue of R-2. 

LABELED. The WG recommends using HUD language.

LISTED. The WG recommends using HUD language.

LOW-VOLTAGE LIGHTING. [Included by WG] Lighting equipment powered through a transformer such as a 

cable conductor, a rail conductor and track lighting. 

HOME MANUFACTURER. [Added by WG] Any person engaged in manufacturing or assembling manufactured 

homes, including any person engaged in importing manufactured homes for resale. 
MANUAL. [Included by WG] Capable of being operated by personal intervention (see “Automatic”). 

PROPOSED DESIGN. [Deleted by WG]

RATED DESIGN. [Deleted by WG]

READILY ACCESSIBLE. [Deleted by WG] 

REPAIR. [Deleted by WG]

REROOFING. [Deleted by WG]

RESIDENTIAL BUILDING. [Deleted by WG]

ROOF ASSEMBLY. [Deleted by WG]

ROOF RECOVER. [Deleted by WG] 

ROOF REPAIR. [Deleted by WG]

ROOF REPLACEMENT. [Deleted by WG]

R-VALUE (THERMAL RESISTANCE). [Included by WG] The inverse of the time rate of heat flow through a 

body from one of its bounding surfaces to the other surface for a unit temperature difference between the two 

surfaces, under steady state conditions, per unit area (h · ft2 

· °F/Btu) [(m2 · K)/W]. 

SERVICE WATER HEATING. [Included by WG] Supply of hot water for purposes other than comfort heating. 

SKYLIGHT. Glass or other transparent or translucent glazing material installed at a slope of less than 60 degrees 

(1.05 rad) from horizontal. 

SOLAR HEAT GAIN COEFFICIENT (SHGC). [Included by WG] The ratio of the solar heat gain entering the 

space through the fenestration assembly to the incident solar radiation. Solar heat gain includes directly transmitted 

solar heat and absorbed solar radiation that is then reradiated, conducted or convected into the space. 

STANDARD REFERENCE DESIGN. [Deleted by WG]

SUNROOM. [Deleted by WG]

THERMAL ENVELOPE. [Deleted by WG]

THERMAL ISOLATION. [Included by WG] Physical and space conditioning separation from conditioned 

space(s). The conditioned space(s) shall be controlled as separate zones for heating and cooling or conditioned by 

separate equipment. 

THERMOSTAT. [Included by WG] An automatic control device used to maintain temperature at a fixed or 

adjustable set point. 

U-FACTOR (THERMAL TRANSMITTANCE). [Included by WG] The coefficient of heat transmission (air to 

air) through a building component or assembly, equal to the time rate of heat flow per unit area and unit temperature 

difference between the warm side and cold side air films (Btu/h · ft2 · °F) [W/(m2 · K)].

VENTILATION. [Included by WG] The natural or mechanical process of supplying conditioned or unconditioned 

air to, or removing such air from, any space. 

VENTILATION AIR. [Included by WG] That portion of supply air that comes from outside (outdoors) plus any 

recirculated air that has been treated to maintain the desired quality of air within a designated space. 

VERTICAL FENESTRATION. [Included by WG] Windows (fixed or moveable), opaque doors, glazed doors, 

glazed block and combination opaque/glazed doors composed of glass or other transparent or translucent glazing 

materials and installed at a slope of a least 60 degrees (1.05 rad) from horizontal. 

VISIBLE TRANSMITTANCE [VT]. [Deleted by WG]

WHOLE HOUSE MECHANICAL VENTILATION SYSTEM. [Included by WG] An exhaust system, supply 

system, or combination thereof that is designed to mechanically exchange indoor air with outdoor air when 

operating continuously or through a programmed intermittent schedule to satisfy the whole house ventilation rates. 

ZONE. [Included by WG] A space or group of spaces within a building with heating or cooling requirements that 

are sufficiently similar so that desired conditions can be maintained throughout using a single controlling device.
CHAPTER 3 [RE]

GENERAL REQUIREMENTS

SECTION R301

CLIMATE ZONES [Deleted – Term Sheet Supersedes]

SECTION R302

DESIGN CONDITIONS

R302.1 Interior design conditions. [Not Discussed by WG] The interior design temperatures used for heating and 

cooling load calculations shall be a maximum of 72°F (22°C) for heating and minimum of 75°F (24°C) for cooling.

SECTION R303

MATERIALS, SYSTEMS AND EQUIPMENT

R303.1 Identification. [Not Discussed by WG] Materials, systems, and equipment shall be identified in a manner 

that will allow a determination of compliance with the applicable provisions of this code.

R303.1.1 Building thermal envelope insulation. [Not Discussed by WG] An R-value identification mark 

shall be applied by the manufacturer to each piece of building thermal envelope insulation 12 inches (305 

mm) or greater in width. Alternately, the insulation installers shall provide a certification listing the type, 

manufacturer and R-value of insulation installed in each element of the building thermal envelope. For 

blown or sprayed insulation (fiberglass and cellulose), the initial installed thickness, settled thickness, 

settled R-value, installed density, coverage area and number of bags installed shall be listed on the 

certification. For sprayed polyurethane foam (SPF) insulation, the installed thickness of the areas covered 

and R-value of installed thickness shall be listed on the certification. For insulated siding, the R-value shall 

be labeled on the product’s package and shall be listed on the certification. The insulation installer shall 

sign, date and post the certification in a conspicuous location on the job site. 

R303.1.1.1 Blown or sprayed roof/ceiling insulation. [Not Discussed by WG] The thickness of 

blown-in or sprayed roof/ceiling insulation (fiberglass or cellulose) shall be written in inches (mm) 

on markers that are installed at least one for every 300 square feet (28 m2

) throughout the attic 

space. The markers shall be affixed to the trusses or joists and marked with the minimum initial 

installed thickness with numbers not 1 inch (25 mm) in height. Each marker shall face the attic 

access opening. Spray polyurethane foam thickness and installed R-value shall be listed on 

certification provided by the insulation installer. 

R303.1.2 Insulation mark installation. [Not Discussed by WG] Insulating materials shall be installed 

such that the manufacturer’s R-value mark is readily observable upon inspection.

R303.1.3 Fenestration product rating. [Not Discussed by WG] U-factors of fenestration products 

(windows, doors and skylights) shall be determined in accordance with NFRC 100.

Exception: Where required, garage door U-factors shall be determined in accordance with either 

NFRC 100 or ANSI/DASMA 105. 

U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by 

the manufacturer.

Products lacking such a labeled U-factor shall be assigned a default U-factor from Table R303.1.3(1) 

or R303.1.3(2). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed 

fenestration products (windows, glazed doors and skylights) shall be determined in accordance with 

NFRC 200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. 

Products lacking such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table 

R303.1.3(3).

TABLE R303.1.3(1) [Included by WG]

DEFAULT GLAZED FENESTRATION U-FACTORS

FRAME TYPE SINGLE 

PANE

DOUBLE 

PANE

SKYLIGHT

Single Double

Metal 1.20 0.80 2.00 1.30

Metal with Thermal Break 1.10 0.65 1.90 1.10

Nonmetal or Metal Clad 0.95 0.55 1.75 1.05

Glazed Block 0.60
TABLE R303.1.3(2)

DEFAULT DOOR U-FACTORS [Included by WG]

DOOR TYPE U-FACTOR

Uninsulated Metal 1.20

Insulated Metal 0.60

Wood 0.50

Insulated, nonmetal edge, max 45% glazing, any 

glazing double pane 0.35

R303.1.4 Insulation product rating. [Not Discussed by WG] The thermal resistance (R-value) of 

insulation shall be determined in accordance with the U.S. Federal Trade Commission R-value rule (CFR 

Title 16, Part 460) in units of h·ft2·°F/Btu at a mean temperature of 75°F (24°C).

R303.1.4.1 Insulated siding. [Not Discussed by WG] The thermal resistance (R-value) of 

insulated siding shall be determined in accordance with ASTM C 1363. Installation for testing 

shall be in accordance with the manufacturer’s instructions.

R303.2 Installation. [Not Discussed by WG] Materials, systems and equipment shall be installed in accordance 

with the manufacturer’s instructions and the International Building Code or International Residential Code, as 

applicable.

R303.2.1 Protection of exposed foundation insulation. [Not Discussed by WG] Insulation applied to the 

exterior of basement walls, crawlspace walls and the perimeter of slab-on-grade floors shall have a rigid, 

opaque and weather-resistant protective covering to prevent the degradation of the insulation’s thermal

performance. The protective covering shall cover the exposed exterior insulation and extend not less than 6

inches (153 mm) below grade.

R303.3 Maintenance information. [Not Discussed by WG] Maintenance instructions shall be furnished for 

equipment and systems that require preventive maintenance. Required regular maintenance actions shall be clearly 

stated and incorporated on a readily accessible label. The label shall include the title or publication number for the 

operation and maintenance manual for that particular model and type of product.

TABLE R303.1.3(3) [Not Discussed by WG]

DEFAULT GLAZED FENESTRATION SHGC AND VT

SINGLE GLAZED DOUBLE GLAZED GLAZED 

Clear Tinted Clear Tinted BLOCK

SHGC 0.8 0.7 0.7 0.6 0.6

VT 0.6 0.3 0.6 0.3 0.6
CHAPTER 4 [RE]

RESIDENTIAL ENERGY EFFICIENCY

SECTION R401

GENERAL

R401.1 Scope. [Not Discussed by WG] This chapter applies to residential buildings.

R401.2 Compliance. [Not Discussed by WG] Projects shall comply with one of the following:

1. Sections R401 through R404.

2. [Deleted – Term Sheet Supersedes]

3. [Deleted – Term Sheet Supersedes]

R401.2.1 Tropical zone. [Deleted – Term Sheet Supersedes]

R401.3 Certificate (Mandatory). [Revised by WG] Refer to the HUD code requirements for data 

plate/compliance certificates.

SECTION R402

BUILDING THERMAL ENVELOPE

R402.1 General (Prescriptive). [Not Discussed by WG] The building thermal envelope shall meet the 

requirements of Sections R402.1.1 through R402.1.5.

Exception: The following low-energy buildings, or portions thereof, separated from the remainder of the 

building by building thermal envelope assemblies complying with this section shall be exempt from the 

building thermal envelope provisions of Section R402.

1. Those with a peak design rate of energy usage less than 3.4 Btu/h · ft2 (10.7 W/m2) or 1.0 watt/ft2 of floor 

area for space-conditioning purposes.

2. Those that do not contain conditioned space.

R402.1.1 Vapor retarder. [Not Discussed by WG] Wall assemblies in the building thermal envelope shall 

comply with the vapor retarder requirements of Section R702.7 of the International Residential Code or 

Section 1405.3 of the International Building Code, as applicable.

R402.1.2 Insulation and fenestration criteria. [Not Discussed by WG] The building thermal envelope 

shall meet the requirements of Table R402.1.2, based on the climate zone specified in Chapter 3.

R402.1.3 R-value computation. [Not Discussed by WG] Insulation material used in layers, such as 

framing cavity insulation, or continuous insulation shall be summed to compute the corresponding 

component R-value. The manufacturer’s settled R-value shall be used for blown insulation. Computed Rvalues shall not include an R-value for other building materials or air films. Where insulated siding is used 

for the purpose of complying with the continuous insulation requirements of Table R402.1.2, the 

manufacturer’s labeled R-value for insulated siding shall be reduced by R-0.6.

R402.1.4 U-factor alternative. [Revised by WG] An assembly with a U-factor equal to or less than that 

specified in the equivalent U-Factor table shall be permitted as an alternative to the R-value in the 

prescriptive table. The U-factor calculation shall be done using a method consistent with the ASHRAE 

handbook of fundamentals and shall include the thermal bridging effects of framing materials.

R402.1.5 Total UA alternative. [Deleted – Term Sheet Supersedes]

R402.2 Specific insulation requirements (Prescriptive). [Not Discussed by WG] In addition to the requirements 

of Section R402.1, insulation shall meet the specific requirements of Sections R402.2.1 through R402.2.13.

R402.2.1 Ceilings with attic spaces. [Deleted – Term Sheet Supersedes]
TABLE R402.1.2

INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa [Deleted – Term Sheet Supersedes]

TABLE R402.1.4

EQUIVALENT U-FACTORSa [Deleted – Term Sheet Supersedes]

R402.2.2 Ceilings without attic spaces. [Deleted by WG]

R402.2.3 Eave baffle. [Included by WG] For air-permeable insulations in vented attics, a baffle shall be 

installed adjacent to soffit and eave vents. Baffles shall maintain an opening equal or greater than the size 

of the vent. The baffle shall extend over the top of the attic insulation. The baffle shall be permitted to be 

any solid material.

R402.2.4 Access hatches and doors. [Revised by WG] Access doors from conditioned spaces to 

unconditioned spaces such as attics and crawl spaces shall be weatherstripped and insulated to a level 

equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that 

prevents damaging or compressing the insulation. A woodframed or equivalent baffle or retainer is required 

to be provided when loose-fill insulation is installed, the purpose of which is to prevent the loose-fill 

insulation from spilling into the living space when the attic access is opened, and to provide a permanent 

means of maintaining the installed R-value of the loose-fill insulation.

R402.2.5 Mass walls. [Deleted by WG]

R402.2.6 Steel-frame ceilings, walls and floors. [Deleted by WG]

R402.2.7 Walls with partial structural sheathing. [Deleted by WG]
R402.2.8 Floors. [Not Discussed by WG] Floor framing-cavity insulation shall be installed to maintain 

permanent contact with the underside of the subfloor decking.

Exception: The floor framing-cavity insulation shall be permitted to be in contact with the topside of 

sheathing or continuous insulation installed on the bottom side of floor framing where combined with 

insulation that meets or exceeds the minimum wood frame wall R-value in Table 402.1.2 and that 

extends from the bottom to the top of all perimeter floor framing members.

R402.2.9 Basement walls. [Not Discussed by WG] Walls associated with conditioned basements shall be 

insulated from the top of the basement wall down to 10 feet (3048 mm) below grade or to the basement 

floor, whichever is less. Walls associated with unconditioned basements shall meet this requirement unless 

the floor overhead is insulated in accordance with Sections R402.1.2 and R402.2.8.

R402.2.10 Slab-on-grade floors. [Not Discussed by WG] Slab-on-grade floors with a floor surface less 

than 12 inches (305 mm) below grade shall be insulated in accordance with Table R402.1.2. The insulation 

shall extend downward from the top of the slab on the outside or inside of the foundation wall. Insulation 

located below grade shall be extended the distance provided in Table R402.1.2 by any combination of 

vertical insulation, insulation extending under the slab or insulation extending out from the building. 

Insulation extending away from the building shall be protected by pavement or by not less than 10 inches 

(254 mm) of soil. The top edge of the insulation installed between the exterior wall and the edge of the 

interior slab shall be permitted to be cut at a 45-degree (0.79 rad) angle away from the exterior wall. Slabedge insulation is not required in jurisdictions designated by the code official as having a very heavy 

termite infestation.

R402.2.11 Crawl space walls. [Not Discussed by WG] As an alternative to insulating floors over crawl 

spaces, crawl space walls shall be permitted to be insulated when the crawl space is not vented to the 

outside. Crawl space wall insulation shall be permanently fastened to the wall and extend downward from 

the floor to the finished grade level and then vertically and/or horizontally for at least an additional 24 

inches (610 mm). Exposed earth in unvented crawl space foundations shall be covered with a continuous 

Class I vapor retarder in accordance with the International Building Code or International Residential 

Code, as applicable. All joints of the vapor retarder shall overlap by 6 inches

(153 mm) and be sealed or taped. The edges of the vapor retarder shall extend not less than 6 inches (153 

mm) up the stem wall and shall be attached to the stem wall.

R402.2.12 Masonry veneer. [Not Discussed by WG] Insulation shall not be required on the horizontal

portion of the foundation that supports a masonry veneer.

R402.2.13 Sunroom insulation. [Not Discussed by WG] Sunrooms enclosing conditioned space shall 

meet the insulation requirements of this code.

Exception: For sunrooms with thermal isolation, and enclosing conditioned space, the following 

exceptions to the insulation requirements of this code shall apply:

1. The minimum ceiling insulation R-values shall be R-19 in Climate Zones 1 through 4 and R-24 in

Climate Zones 5 through 8.

2. The minimum wall R-value shall be R-13 in all climate zones. Walls separating a sunroom with a

thermal isolation from conditioned space shall meet the building thermal envelope requirements

of this code.

R402.3 Fenestration (Prescriptive). [Not Discussed by WG] In addition to the requirements of Section R402,

fenestration shall comply with Sections R402.3.1 through R402.3.6.

R402.3.1 U-factor. [Deleted – Term Sheet Supersedes]

R402.3.2 Glazed fenestration SHGC. [Deleted – Term Sheet Supersedes]

R402.3.3 Glazed fenestration exemption. [Deleted – Term Sheet Supersedes]

R402.3.4 Opaque door exemption. [Not Discussed by WG] One side-hinged opaque door assembly up to 

24 square feet (2.22 m2) in area is exempted from the U-factor requirement in Section R402.1.4. This 

exemption shall not apply to the U-factor alternative approach in Section R402.1.4 and the total UA

alternative in Section R402.1.5.

R402.3.5 Sunroom fenestration. [Not Discussed by WG] Sunrooms enclosing conditioned space shall 

meet the fenestration requirements of this code.

Exception: For sunrooms with thermal isolation and enclosing conditioned space in Climate Zones 2 

through 8, the maximum fenestration U-factor shall be 0.45 and the maximum skylight U-factor shall 
be 0.70. New fenestration separating the sunroom with thermal isolation from conditioned space shall 

meet the building thermal envelope requirements of this code.

R402.4 Air leakage (Mandatory). [Not Discussed by WG] The building thermal envelope shall be constructed to 

limit air leakage in accordance with the requirements of Sections R402.4.1 through R402.4.4.

R402.4.1 Building thermal envelope. [Revised by WG] The building thermal envelope shall comply with 

Sections R402.4.1.1. The sealing methods between dissimilar materials shall allow for differential 

expansion and contraction.

R402.4.1.1 Installation. [Revised by WG] The components of the building thermal envelope as 

listed in Table R402.4.1.1 shall be installed in accordance with the manufacturer’s instructions and 

the criteria listed in Table R402.4.1.1, as applicable to the method of construction. 

R402.4.1.2 Testing. [Deleted by WG]

R402.4.2 Fireplaces. [Revised by WG] Where using tight-fitting doors on masonry fireplaces, the doors 

shall be listed and labeled in accordance with UL 907.

R402.4.3 Fenestration Air Leakage. [Deleted by WG] 

R402.4.4 Rooms containing fuel-burning appliances. [Deferred to DOE by WG] In Climate Zones 3 

through 8, where open combustion air ducts provide combustion air to open combustion fuel burning 

appliances, the appliances and combustion air opening shall be located outside the building thermal 

envelope or enclosed in a room, isolated from inside the thermal envelope. Such rooms shall be sealed and 

insulated in accordance with the envelope requirements of

Table R402.1.2, where the walls, floors and ceilings shall meet not less than the basement wall R-value 

requirement.

The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in 

accordance with Section R403. The combustion air duct shall be insulated where it passes through

conditioned space to a minimum of R-8.

Exceptions:

1. Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.

2. Fireplaces and stoves complying with Section R402.4.2 and Section R1006 of the International

Residential Code.

R402.4.5 Recessed lighting. [Not Discussed by WG] Recessed luminaires installed in the building 

thermal envelope shall be sealed to limit air leakage between conditioned and unconditioned spaces. All 

recessed luminaires shall be IC-rated and labeled as having an air leakage rate not more than 2.0 cfm 

(0.944 L/s) when tested in accordance with ASTM E 283 at a 1.57 psf (75 Pa) pressure differential. All 

recessed luminaires shall be sealed with a gasket or caulk between the housing and the interior wall or 

ceiling covering.

R402.5 Maximum fenestration U-factor and SHGC (Mandatory). [Included in Concept by WG] The areaweighted average maximum fenestration U-factor permitted using tradeoffs from Section [Total UA/REScheck 

option] or [Uo option] shall be 0.40 in HUD Climate Zones 2 through 3 . The area-weighted average maximum 

fenestration SHGC permitted using tradeoffs from Section [Total UA/REScheck option] or [Uo option] in HUD

Climate Zones 1 through 2 shall be 0.40.
TABLE R402.4.1.1

AIR BARRIER AND INSULATION INSTALLATION

COMPONENT AIR BARRIER CRITERIA INSULATION INSTALLATION CRITERIA

General requirements A continuous air barrier shall be installed 

in the building envelope.

The exterior thermal envelope contains a 

continuous air barrier.

Breaks or joints in the air barrier shall be 

sealed. [Included by WG]

Air-permeable insulation shall not be used 

as a sealing material. [Included by WG]

Ceiling/attic The air barrier in any dropped ceiling/soffit 

shall be aligned with the insulation and any 

gaps in the air barrier shall be sealed.

Access openings, drop down stairs or knee 

wall doors to unconditioned attic spaces 

shall be sealed. [Included by WG]

The insulation in any dropped ceiling/soffit 

shall be aligned with the air barrier.

[Included by WG]

Walls The junction of the top plate and the ceiling

along exterior walls shall be sealed.

The junction of the bottom plate and the floor 

along exterior walls shall be sealed. [Revised

by WG]

Air permeable exterior thermal envelope 

insulation for framed walls shall 

completely fill the cavity, including within 

stud bays caused by blocking lay flats or 

headers. [Revised by WG]

Windows, skylights and doors The space between window/door jambs 

and framing, and skylights and framing 

shall be sealed. [Included by WG]

Rim joists Rim joists shall include the air barrier.

[Included by WG]

Rim joists shall be insulated. [Included by 

WG]

Floors [Revised by WG] The air barrier shall be installed at any 

exposed edge of insulation. The bottom 

board may serve as the air barrier. [Revised 

by WG]

[Deleted by WG]

[Deleted by WG] Crawl space walls [Deleted by WG] [Deleted by WG]

Shafts, penetrations Duct shafts, utility penetrations, and flue 

shafts that penetrate the air barrier shall be

sealed. [Revised by WG]

Narrow cavities Batts in narrow cavities shall be cut to fit, 

or narrow cavities shall be filled by 

insulation that on installation readily 

conforms to the available cavity space.

[Included by WG]

Garage Separation [Deleted by WG] [Deleted by WG]

Recessed lighting Recessed light fixtures installed in the 

building thermal envelope shall be sealed 

to the drywall. [Included by WG]

Recessed light fixtures installed in the 

building thermal envelope shall be air tight 

and IC rated. [Included by WG]

Plumbing and Wiring [Deleted by WG] [Deleted by WG]

Shower/tub on exterior wall The air barrier installed at exterior walls 

adjacent to showers and tubs shall separate 

them from the showers and tubs. [Included 

by WG]

Exterior walls adjacent to showers and tubs 

shall be insulated. [Included by WG]

Electrical/phone box on exterior walls The air barrier shall be installed behind 

electrical or communication boxes or the 

air barrier shall be sealed around the box 

penetration. [Revised by WG]

HVAC register boots HVAC register boots that penetrate 

building thermal envelope shall be sealed 

to the subfloor or drywall. [Included by 

WG]

Concealed sprinklers [Deleted by WG] [Deleted by WG]
SECTION R403

SYSTEMS

R403.1 Controls (Mandatory). [Included by WG] At least one thermostat shall be provided for each separate 

heating and cooling system.

R403.1.1 Programmable thermostat. [Included by WG]The thermostat controlling the primary heating 

or cooling system of the dwelling unit shall be capable of controlling the heating and cooling system on a 

daily schedule to maintain different temperature set points at different times of the day. This thermostat 

shall include the capability to set back or temporarily operate the system to maintain zone temperatures 

down to 55°F (13°C) or up to 85°F (29°C). The thermostat shall initially be programmed by the 

manufacturer with a heating temperature set point no higher than 70°F (21°C) and a cooling temperature set 

point no lower than 78°F (26°C).

R403.1.2 Heat pump supplementary heat (Mandatory). [Included by WG] Heat pumps having 

supplementary electric-resistance heat shall have controls that, except during defrost, prevent supplemental 

heat operation when the heat pump compressor can meet the heating load.

R403.2 Hot water boiler outdoor temperature setback. [Not Discussed by WG] Hot water boilers that supply 

heat to the building through one- or two-pipe heating systems shall have an outdoor setback control that lowers the

boiler water temperature based on the outdoor temperature.

R403.3 Ducts. [Not Discussed by WG] Ducts and air handlers shall be in accordance with Sections R403.3.1 

through R403.3.5.

R403.3.1 Insulation (Prescriptive). [Not Discussed by WG] Supply and return ducts in attics shall be 

insulated to a minimum of R-8 where 3 inches (76 mm) in diameter and greater and R-6 where less than 3 

inches (76 mm) in diameter. Supply and return ducts in other portions of the building shall be insulated to a 

minimum of R-6 where 3 inches (76 mm) in

diameter or greater and R-4.2 where less than 3 inches (76 mm) in diameter.

Exception: Ducts or portions thereof located completely inside the building thermal envelope.

R403.3.2 Sealing (Mandatory). [Not Discussed by WG] Ducts, air handlers and filter boxes shall be 

sealed. Joints and seams shall comply

with either the International Mechanical Code or International Residential Code, as applicable.

Exceptions:

1. Air-impermeable spray foam products shall be permitted to be applied without additional joint

seals.

2. For ducts having a static pressure classification of less than 2 inches of water column (500 Pa),

additional closure systems shall not be required for continuously welded joints and seams, and

locking-type joints and seams of other than the snap-lock and button-lock types.

R403.3.2.1 Sealed air handler. [Not Discussed by WG] Air handlers shall have a manufacturer’s 

designation for an air leakage of no more than 2 percent of the design air flow rate when tested in 

accordance with ASHRAE 193.

R403.3.3 Duct testing (Mandatory). [Deleted – Term Sheet Supersedes] 

R403.3.4 Duct leakage (Prescriptive). [Deleted – Term Sheet Supersedes] 

R403.3.5 Building cavities (Mandatory). [Included by WG] Building framing cavities shall not be used 

as ducts or plenums.

R403.4 Mechanical system piping insulation (Mandatory). [Deleted – Term Sheet Supersedes]

R403.4.1 Protection of piping insulation. [Not Discussed by WG] Piping insulation exposed to weather 

shall be protected from damage, including that caused by sunlight, moisture, equipment maintenance and 

wind, and shall provide shielding from solar radiation that can cause degradation of the material. Adhesive 

tape shall not be permitted.

R403.5 Service hot water systems. [Not Discussed by WG] Energy conservation measures for service hot water 

systems shall be in accordance with Sections R403.5.1 and R403.5.4.

R403.5.1 Heated water circulation and temperature maintenance systems (Mandatory). [Included by 

WG] Heated water circulation systems shall be in accordance with Section R403.5.1.1. Heat trace 

temperature maintenance systems shall be in accordance with Section R403.5.1.2. Automatic controls, 

temperature sensors and pumps shall be accessible. Manual controls shall be readily accessible.

R403.5.1.1 Circulation systems. [Included by WG] Heated water circulation systems shall be 

provided with a circulation pump. The system return pipe shall be a dedicated return pipe or a cold 

water supply pipe. Gravity and thermosyphon circulation systems shall be prohibited. Controls for 
circulating hot water system pumps shall start the pump based on the identification of a demand 

for hot water within the occupancy. The controls shall automatically turn off the pump when the 

water in the circulation loop is at the desired temperature and when there is no demand for hot 

water.

R403.5.1.2 Heat trace systems. [Included by WG] Electric heat trace systems shall comply with

IEEE 515.1 or UL 515. Controls for such systems shall automatically adjust the energy input to 

the heat tracing to maintain the desired water temperature in the piping in accordance with the 

times when heated water is used in the occupancy.

R403.5.2 Demand recirculation systems. [Not Discussed by WG] A water distribution system having 

one or more recirculation pumps that pump water from a heated water supply pipe back to the heated water 

source through a cold water supply pipe shall be a demand recirculation water system. Pumps shall have 

controls that comply with both of the following:

1. The control shall start the pump upon receiving a signal from the action of a user of a fixture or 

appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a 

fixture fitting or appliance.

2. The control shall limit the temperature of the water entering the cold water piping to 104oF (40oC).

R403.5.3 Hot water pipe insulation (Prescriptive). [Deleted – Term Sheet Supersedes]

R403.5.4 Drain water heat recovery units. [Not Discussed by WG] Drain water heat recovery units shall 

comply with CSA B55.2. Drain water heat recovery units shall be tested in accordance with CSA B55.1. 

Potable water-side pressure loss of drain water heat recovery units shall be less than 3 psi (20.7 kPa) for 

individual units connected to one or two showers. Potable water-side pressure loss of drain water heat 

recovery units shall be less than 2 psi (13.8 kPa) for individual units connected to three or more showers.

R403.6 Mechanical Ventilation (Mandatory) [Revised by WG] The building shall be provided with ventilation 

that meets the requirements of the 24 CFR Part 3280 Manufactured Home Construction and Safety Standards. 

Whole-house mechanical ventilation system fan efficacy shall meet the efficacy requirements of Table R403.6.1.

Exception: Where mechanical ventilation fans are integral to tested and listed HVAC equipment, they 

shall be powered by an electronically commutated motor.

R403.6.1 Whole-house mechanical ventilation system fan efficacy. [Deleted by WG]

R403.7 Equipment sizing and efficiency rating (Mandatory). [Revised by WG] Heating and cooling equipment 

shall be sized in accordance with ACCA Manual S based on building loads calculated in accordance with ACCA 

Manual J or other DOE approved heating and cooling calculation methodologies.

R403.8 Systems serving multiple dwelling units (Mandatory). [Deleted by WG]

R403.9 Snow melt and ice system controls (Mandatory). [Deleted by WG]

TABLE R403.6.1 [Included by WG]

MECHANICAL VENTILATION SYSTEM FAN EFFICACY

FAN LOCATION AIR FLOW RATE 

MINIMUM (CFM)

MINIMUM EFFICACY 

(CFM/WATT)

AIR FLOW RATE 

MAXIMUM (CFM)

Range hoods Any 2.8 Any

In-line fan Any 2.8 Any

bathroom, utility room 10 1.4 <90

bathroom utility room 90 2.8 Any

For SI: 1 cfm = 28.3 L/min.

R403.10 Pools and permanent spa energy consumption (Mandatory). [Deleted by WG]

R403.10.1 Residential pools and permanent residential spas. [Deleted by WG]

R403.10.2 Heaters. [Deleted by WG]

R403.10.3 Time switches. [Deleted by WG]

R403.10.4 Covers. [Deleted by WG]

R403.11 Portable spas (Mandatory). [Deleted by WG]

R403.12 Residential pools and permanent residential spas. [Not Discussed by WG] Residential swimming pools 

and permanent residential spas that are accessory to detached one- and two-family dwellings and townhouses three 
stories or less in height above grade plane and that are available only to the household and its guests shall be in 

accordance with APSP-15.

SECTION R404

ELECTRICAL POWER AND LIGHTING SYSTEMS

R404.1 Lighting equipment (Mandatory). [Included by WG] Not less than 75 percent of the lamps in 

permanently installed lighting fixtures shall be high-efficacy lamps or not less than 75 percent of the permanently

installed lighting fixtures shall contain only high-efficacy lamps.

Exception: Low-voltage lighting.

R404.1.1 Lighting equipment (Mandatory). [Not Discussed by WG] Fuel gas lighting systems shall not 

have continuously burning pilot lights.

SECTION R405 [Deleted – Term Sheet Supersedes]

SECTION R406 [Deleted – Term Sheet Supersedes]

CHAPTER 5 (RE)

EXISTING BUILDINGS

[Not Discussed by WG]

SECTION R501

GENERAL

R501.1 Scope. [Not Discussed by WG] The provisions of this chapter shall control the alteration, repair, addition 

and change of occupancy of existing buildings and structures.

R501.1.1 Additions, alterations, or repairs: General. [Not Discussed by WG] Additions, alterations, or 

repairs to an existing building, building system or portion thereof shall comply with Section R502, R503 or 

R504. Unaltered portions of the existing building or building supply system shall not be required to comply 

with this code.

R501.2 Existing buildings. [Not Discussed by WG] Except as specified in this chapter, this code shall not be used 

to require the removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing 

building or building system lawfully in existence at the time of adoption of this code.

R501.3 Maintenance. [Not Discussed by WG] Buildings and structures, and parts thereof, shall be maintained in a 

safe and sanitary condition. Devices and systems that are required by this code shall be maintained in conformance 

to the code edition under which installed. The owner or the owner’s authorized agent shall be responsible for the 

maintenance of buildings and structures. The requirements of this chapter shall not provide the basis for removal or 

abrogation of energy conservation, fire protection and safety systems and devices in existing structures.

R501.4 Compliance. [Not Discussed by WG] Alterations, repairs, additions and changes of occupancy to, or 

relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions 

and changes of occupancy or relocation, respectively, in the International Residential Code, International Building 

Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, International

Plumbing Code, International Property Maintenance Code, International Private Sewage Disposal Code and NFPA 

70.

R501.5 New and replacement materials. [Not Discussed by WG] Except as otherwise required or permitted by

this code, materials permitted by the applicable code for new construction shall be used. Like materials shall be 

permitted for repairs, provided hazards to life, health or property are not created. Hazardous materials shall not be 

used where the code for new construction would not permit their use in buildings of similar occupancy, purpose and 

location.

R501.6 Historic buildings. [Not Discussed by WG] No provision of this code relating to the construction, repair, 

alteration, restoration and movement of structures, and change of occupancy shall be mandatory for historic 

buildings provided a report has been submitted to the code official and signed by the owner, a registered design 

professional, or a representative of the State Historic Preservation Office or the historic preservation authority 

having jurisdiction, demonstrating that compliance with that provision would threaten, degrade or destroy the 

historic form, fabric or function of the building.

SECTION R502

ADDITIONS
R502.1 General. [Not Discussed by WG] Additions to an existing building, building system or portion thereof 

shall conform to the provisions of this code as those provisions relate to new construction without requiring the 

unaltered portion of the existing building or building system to comply with this code. Additions shall not create an 

unsafe or hazardous condition or overload existing building systems. An addition shall be deemed to comply with 

this code where the addition alone complies, where the existing building and addition comply with this code as a 

single building, or where the building with the addition uses no more energy than the existing building. Additions 

shall be in accordance with Section R502.1.1 or R502.1.2.

R502.1.1 Prescriptive compliance. [Not Discussed by WG] Additions shall comply with Sections 

R502.1.1.1 through R502.1.1.4.

R502.1.1.1 Building envelope. [Not Discussed by WG] New building envelope assemblies that 

are part of the addition shall comply with Sections R402.1, R402.2, R402.3.1 through R402.3.5, 

and R402.4.

Exception: Where nonconditioned space is changed to conditioned space, the building 

envelope of the addition shall comply where the UA, as determined in Section 402.1.4, of the 

existing building and the addition, and any alterations that are part of the project, is less than 

or equal to UA generated for the existing building.

R502.1.1.2 Heating and cooling systems. [Not Discussed by WG] New heating, cooling and 

duct systems that are part of the addition shall comply with Sections R403.1, R403.2, R403.3, 

R403.5 and R403.6.

Exception: Where ducts from an existing heating and cooling system are extended to an 

addition, duct systems with less than 40 linear feet (12.19 m) in unconditioned spaces shall 

not be required to be tested in accordance with Section R403.3.3.

R502.1.1.3 Service hot water systems. [Not Discussed by WG] New service hot water systems 

that are part of the addition shall comply with Section R403.4.

R502.1.1.4 Lighting. [Not Discussed by WG] New lighting systems that are part of the addition 

shall comply with Section R404.1.

R502.1.2 Existing plus addition compliance (Simulated Performance Alternative). [Not Discussed by 

WG] Where nonconditioned space is changed to conditioned space, the addition shall comply where the 

annual energy cost or energy use of the addition and the existing building, and any alterations that are part

of the project, is less than or equal to the annual energy cost of the existing building when modeled in 

accordance with Section R405. The addition and any alterations that are part of the project shall comply 

with Section R405 in its entirety.

SECTION R503

ALTERATIONS

R503.1 General. [Not Discussed by WG] Alterations to any building or structure shall comply with the 

requirements of the code for new construction. Alterations shall be such that the existing building or structure is no 

less conforming to the provisions of this code than the existing building or structure was prior to the alteration.

Alterations to an existing building, building system or portion thereof shall conform to the provisions of this code as 

they relate to new construction without requiring the unaltered portions of the existing building or building system to 

comply with this code. Alterations shall not create an unsafe or hazardous condition or overload existing building 

systems. Alterations shall be such that the existing building or structure uses no more energy than the existing 

building or structure prior to the alteration. Alterations to existing buildings shall comply with Sections R503.1.1 

through R503.2.

R503.1.1 Building envelope. [Not Discussed by WG] Building envelope assemblies that are part of the 

alteration shall comply with Section R402.1.2 or R402.1.4, Sections R402.2.1 through R402.2.12, 

R402.3.1, R402.3.2, R402.4.3 and R402.4.4.

Exception: The following alterations need not comply with the requirements for new construction 

provided the energy use of the building is not increased:

1. Storm windows installed over existing fenestration.

2. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are 

filled with insulation.

3. Construction where the existing roof, wall or floor cavity is not exposed.

4. Roof recover.
5. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during

reroofing shall be insulated either above or below the sheathing.

6. Surface-applied window film installed on existing single pane fenestration assemblies to reduce

solar heat gain provided the code does not require the glazing or fenestration assembly to be

replaced.

R503.1.1.1 Replacement fenestration. [Not Discussed by WG] Where some or all of an existing 

fenestration unit is replaced with a new fenestration product, including sash and glazing, the 

replacement fenestration unit shall meet the applicable requirements for U-factor and SHGC as 

provided in Table R402.1.4.

R503.1.2 Heating and cooling systems. [Not Discussed by WG] New heating, cooling and duct systems 

that are part of the alteration shall comply with Sections R403.1, R403.2, R403.3 and R403.6.

Exception: Where ducts from an existing heating and cooling system are extended, duct systems with 

less than 40 linear feet (12.19 m) in unconditioned spaces shall not be required to be tested in 

accordance with Section R403.3.3.

R503.1.3 Service hot water systems. [Not Discussed by WG] New service hot water systems that are part

of the alteration shall comply with Section R403.4.

R503.1.4 Lighting. [Not Discussed by WG] New lighting systems that are part of the alteration shall 

comply with Section 404.1.

Exception: Alterations that replace less than 50 percent of the luminaires in a space, provided that 

such alterations do not increase the installed interior lighting power.

R503.2 Change in space conditioning. [Not Discussed by WG] Any nonconditioned or low-energy space that is 

altered to become conditioned space shall be required to be brought into full compliance with this code.

Exception: Where the simulated performance option in Section R405 is used to comply with this section, the 

annual energy cost of the proposed design is permitted to be 110 percent of the annual energy cost otherwise 

allowed by Section R405.3.

SECTION R504

REPAIRS

R504.1 General. [Not Discussed by WG] Buildings, structures and parts thereof shall be repaired in compliance 

with Section R501.3 and this section. Work on nondamaged components necessary for the required repair of 

damaged components shall be considered part of the repair and shall not be subject to the requirements for 

alterations in this chapter. Routine maintenance required by Section R501.3, ordinary repairs exempt from permit, 

and abatement of wear due to normal service conditions shall not be subject to the requirements for repairs in this 

section.

R504.2 Application. [Not Discussed by WG] For the purposes of this code, the following shall be considered 

repairs:

1. Glass-only replacements in an existing sash and frame.

2. Roof repairs.

3. Repairs where only the bulb and/or ballast within the existing luminaires in a space are replaced provided that 

the replacement does not increase the installed interior lighting power.

SECTION R505

CHANGE OF OCCUPANCY OR USE

R505.1 General. [Not Discussed by WG] Spaces undergoing a change in occupancy that would result in an 

increase in demand for either fossil fuel or electrical energy shall comply with this code.

R505.2 General. [Not Discussed by WG] Any space that is converted to a dwelling unit or portion thereof from

another use or occupancy shall comply with this code.

Exception: Where the simulated performance option in Section R405 is used to comply with this section, the 

annual energy cost of the proposed design is permitted to be 110 percent of the annual energy cost otherwise 

allowed by Section R405.3.
CHAPTER 6

REFERENCED STANDARDS

[Not Discussed by WG]

This chapter lists the standards that are referenced in various sections of this document. The standards are listed 

herein by the promulgating agency of the standard, the standard identification, the effective date and title, and the 

section or sections of this document that reference the standard. The application of the referenced standards shall be 

as specified in Section 106.

AAMA

American Architectural Manufacturers Association 

1827 Walden Office Square

Suite 550

Schaumburg, IL 60173-4268

Standard reference number Title

Referenced in 

code section 

number

AAMA/WDMA/CSA

101/I.S.2/A C440—11 North American Fenestration Standard/Specifications for 

Windows, Doors, and Unit Skylights R402.4.3

ACCA

Air Conditioning Contractors of America

2800 Shirlington Road, Suite 300

Arlington, VA 22206

Standard reference number Title

Referenced in 

code section 

number

Manual J—2011 Residential Load Calculation Eighth Edition R403.7

Manual S—13 Residential Equipment Selection R403.7

APSP

The Association of Pool and Spa Professionals

2111 Eisenhower Avenue

Alexandria, VA 22314

Standard reference number Title

Referenced in 

code section 

number

APSP 14—11 

American National Standard for Portable Electric Spa Energy 

Efficiency R403.10.1,403.11

APSP 15a—2013 

American National Standard for Residential Swimming Pool 

and Spa Energy Efficiency R403.12

ASHRAE

American Society of Heating, Refrigerating and AirConditioning Engineers, Inc.

1791 Tullie Circle, NE

Atlanta, GA 30329-2305

Standard reference number Title

Referenced in 

code section 

number

ASHRAE—2013 ASHRAE Handbook of Fundamentals

R402.1.5, Table 

R405.5.2(1)

ASHRAE 193—2010 

Method of Test for Determining the Airtightedness of HVAC 

Equipment R403.3.2.1
ASTM

ASTM International 

100 Barr Harbor Drive

West Conshohocken, PA 19428-2859

Standard reference number Title

Referenced in 

code section 

number

C 1363—11

Standard Test Method for Thermal Performance of Building 

Materials and Envelope Assemblies by Means of a Hot Box 

Apparatus R303.1.4.1

E 283—04 

Test Method for Determining the Rate of Air Leakage 

Through Exterior Windows, Curtain Walls and Doors Under 

Specified Pressure Differences Across the Specimen R402.4.4

E 779—10 

Standard Test Method for Determining Air Leakage Rate by 

Fan Pressurization R402.4.1.2

E 1827—11 

Standard Test Methods for Determining Airtightness of 

Building Using an Orifice Blower Door R402.4.1.2

CSA

CSA Group

8501 East Pleasant Valley

Cleveland, OH 44131-5575

Standard reference number Title

Referenced in 

code section 

number

AAMA/WDMA/CSA 

101/I.S.2/A440—11 

North American Fenestration Standard/Specification for 

Windows, Doors and Unit Skylights R402.4.3

CSA 55.1—2012

Test Method for measuring efficiency and pressure loss of 

drain water heat recovery units R403.5.4

CSA 55.2—2012 Drain water heat recover units R403.5.4

DASMA

Door and Access Systems Manufacturers Association

1300 Sumner Avenue

Cleveland, OH 44115-2851

Standard reference number Title

Referenced in 

code section 

number

105—92(R2004)—13 

Test Method for Thermal Transmittance and Air Infiltration of 

Garage Doors R303.1.3
ICC

International Code Council, Inc.

500 New Jersey Avenue, NW

6th Floor

Washington, DC 20001

Standard reference number Title

Referenced in 

code section 

number

IBC—15 International Building Code®

R201.3, R303.2, 

R402.1.1, R501.4

ICC 400—12 Standard on the Design and Construction of Log Structures Table R402.5.1.1

IECC—15 International Energy Conservation Code® R101.4.1, 403.8

IECC—09 2009 International Energy Conservation Code® R406.2

ECC—06 2006 International Energy Conservation Code® R202, R406.3.1

IFC—15 International Fire Code® R201.3, R501.4

IFGC—15 International Fuel Gas Code® R201.3, R501.4

IMC—15 International Mechanical Code®

R201.3, R403.3.2, 

R403.6, R501.4

IPC—15 International Plumbing Code® R201.3, R501.4

IPSDC—15 International Private Sewage Disposal Code® R501.4

IPMC—15 International Property Maintenance Code® R501.4

IRC—15 International Residential Code® 

R201.3, R303.2, 

R402.1.1, 

R402.2.11, 

R403.3.2, R403.6, 

R501.4

IEEE

The Institute of Electrical and Electronic Engineers, Inc.

3 Park Avenue

New York, NY 1016-5997

Standard reference number Title

Referenced in 

code section 

number

515.1—2012

IEEE Standard for the Testing, Design, Installation, and 

Maintenance of Electrical Resistance Trace Heating for 

Commercial Applications R403.5.1.2

NFPA

National Fire Protection Association

1 Battermarch Park

Quincy, MA 02169-7471

Standard reference number Title

Referenced in 

code section 

number

70—14 National Electrical Code R501.4
NFRC

National Fenestration Rating Council, Inc.

6305 Ivy Lane, Suite 140

Greenbelt, MD 20770

Standard reference number Title

Referenced in 

code section 

number

100—2009 

Procedure for Determining Fenestration Products U-factors—Second 

Edition R303.1.3

200—2009 

Procedure for Determining Fenestration Product Solar Heat Gain 

Coefficients and Visible Transmittance at Normal Incidence—Second 

Edition R303.1.3

400—2009 

Procedure for Determining Fenestration Product Air Leakage—Second 

Edition R402.4.3

UL

UL LLC

333 Pfingsten Road

Northbrook, IL 60062

Standard reference number Title

Referenced in 

code section 

number

127—11 Standard for Factory Built Fireplaces R402.4.2

515—11 

Electrical Resistance Heat Tracing for Commercial and Industrial 

Applications including revisions through November 30, 2011 R403.5.1.2

US-FTC

United States-Federal Trade Commission

600 Pennsylvania Avenue NW

Washington, DC 20580

Standard reference number Title

Referenced in 

code section 

number

CFR Title 16 (May 31, 

2005) R-value Rule R303.1.4

WDMA

Window and Door Manufacturers Association

2025 M street, NW Suite 800

Washington, DC 20036-3309

Standard reference number Title

Referenced in 

code section 

number

AAMA/WDMA/CSA 

101/I.S.2/A440—11 

North American Fenestration Standard/Specification for Windows, Doors 

and Unit Skylights R402.4.3