DEPARTMENT OF LICENSING AND REGULATORY AFFAIRS  
DIRECTOR’S OFFICE  
CONSTRUCTION CODE  
(By authority conferred on the director of the department of licensing and regulatory  
affairs by section 4 of 1972 PA 230, MCL 125.1504, and Executive Reorganization  
Order Nos. 2003-1 and 2008-4, 2011-4, MCL 445.2011 and MCL 445.2025)  
PART 10. MICHIGAN UNIFORM ENERGY CODE  
R 408.31001 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31002 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31003 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31004 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31005 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31006 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31007 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
Page 1  
R 408.31008 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31009 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31010 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31011 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31012 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31013 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31014 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31015 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31016 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31017 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
Page 2  
R 408.31018 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31019 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31020 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31021 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31022 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31023 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31024 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31025 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31026 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31027 Rescinded.  
Page 3  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31028 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31029 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31030 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31031 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31032 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31033 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31034 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31035 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31036 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31037 Rescinded.  
Page 4  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31038 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31039 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31040 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31041 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31042 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31043 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31044 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31045 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31046 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31047 Rescinded.  
Page 5  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31048 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31049 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31050 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31051 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31052 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31053 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31054 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
R 408.31055 Rescinded.  
History: 1979 AC; 1981 AACS; 1998-2000 AACS.  
PART 10 MICHIGAN ENERGY CODE  
R 408.31059 Applicable code.  
Page 6  
Rule 1059. The residential provisions of the international energy conservation code,  
2015 edition, except for sections R107.2 to R107.5, R301.2, R301.3, R402.3.2, and Table  
R303.1.3(3), govern the energy efficiency for the design and construction of residential  
buildings and, with exceptions noted, the international energy conservation code is  
adopted by reference in these rules. All references to the international building code,  
international residential code, international energy conservation code, international  
electrical code, international existing building code, international mechanical code, and  
international plumbing code mean the Michigan building code, Michigan residential  
code, Michigan energy code, Michigan electrical code, Michigan rehabilitation code for  
existing buildings, Michigan mechanical code, and Michigan plumbing code respectively.  
The Michigan energy code is available for inspection or purchase at the Okemos office of  
the Michigan Department of Licensing and Regulatory Affairs, Bureau of Construction  
Codes, 2501 Woodlake Circle, Okemos, Michigan 48864, at a cost as of the time of  
adoption of these rules of $44.00 or may be purchased from the International Code  
Council, 500 New Jersey Avenue, N.W., 6th Floor, Washington, D.C. 20001.  
History: 2008 AACS; 2010 AACS; 2015 AACS.  
R 408.31060 Scope; requirements.  
Rule 1060. Sections R101.1, R101.4.3, and R102.1.1 of the code are amended to  
read as follows:  
R101.1. Title. This code shall be known and cited as the “Michigan Energy Code.”  
It is referred to herein as “this code.”  
R101.4.3. Additions, alterations, renovations, or repairs. Additions, alterations,  
renovations, or repairs 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 portion or portions of the existing building or building system to  
comply with this code. Additions, alterations, renovations, or repairs shall not create an  
unsafe or hazardous condition or overload existing building systems. An addition shall  
be deemed to comply with this code if the addition alone complies or if the existing  
building and addition comply with this code as a single building.  
Exception: The following need not comply provided the energy use of the building  
is not increased:  
1. Storm windows installed over existing fenestration.  
2. Glass only replacements in an existing sash and frame.  
3. Existing ceiling, wall, or floor cavities exposed during construction provided that  
these cavities are filled with insulation.  
4. Construction where the existing roof, wall, or floor cavity is not exposed.  
5. Reroofing where the roof is part of the thermal envelope and where neither the  
roof sheathing nor the roof insulation is exposed.  
6. Reroofing where the roof is not part of the thermal envelope.  
7. Replacement of existing doors that separate conditioned space from the exterior  
shall not require the installation of a vestibule or revolving door, provided, however, that  
an existing vestibule that separates a conditioned space from the exterior shall not be  
removed.  
Page 7  
8. Alterations that replace less than 50% of the luminaires in a space, provided that  
such alterations do not increase the installed interior lighting power.  
9. Alterations that replace only the bulb and ballast within the existing luminaires in  
a space provided that the alteration does not increase the installed interior lighting power.  
R 102.1.1 Above code programs.  
The state construction code commission may evaluate and approve a national, state,  
or local energy efficiency program to exceed the energy efficiency required by this code.  
Buildings approved in writing by such an energy efficiency program, such as ICC 700-  
2012 “silver” or energy star version 3 (rev. 07), shall be considered in compliance with  
this code. The requirements identified as “mandatory” in chapter 4 shall be met.  
History: 2008 AACS; 2010 AACS; 2015 AACS.  
R 408.31060a Construction documents.  
Rule 1060a. Section 103.1 of the code is amended to read as follows:  
103.1. Submittal documents. Construction documents, special inspection and  
structural programs, and other data shall meet both of the following requirements:  
(1) Submitted in 1 or more sets with each application for a permit.  
(2) Prepared by, or under the direct supervision of, a registered design professional  
when required by 1980 PA 299, MCL 339.101 to 339.2721. Where special conditions  
exist, the building official is authorized to require additional construction documents  
to be prepared by a registered design professional.  
History: 2010 AACS.  
R 408.31060b Fees.  
Rule 1060b. Section 107.1 of the code is amended to read as follows:  
107.1. Payment of fees. The fees prescribed by the act shall be paid to the  
enforcing agency of the jurisdiction before a permit to begin work for new  
construction, alteration, removal, demolition, or other building operation may be  
issued. In addition, an amendment to a permit necessitating an additional fee shall not be  
approved until the additional fee has been paid.  
History: 2010 AACS.  
R 408.31060c Board of appeals.  
Rule 1060c. Sections 109.1 and 109.3 of the code are amended to read as follows:  
109.1 Means of appeal. (1) An interested person may appeal a decision of the  
enforcing agency to the board of appeals in accordance with the act. An application for  
appeal shall be based on both of the following:  
(a) A claim that the true intent of the code or the rules governing construction  
have been incorrectly interpreted.  
(b) The provisions of the code do not apply, or an equal or better form of  
construction is proposed.  
Page 8  
(2) The decision of a local board of appeals may be appealed to the  
construction code commission in accordance with the act and time frames.  
Exception: Requests for barrier free design exception shall be in accordance  
with 1966 PA 1, MCL 125.1352 to 125.1356.  
109.3 Qualifications. The board of appeals shall consist of members who are  
qualified in accordance with the act.  
History: 2010 AACS.  
R 408.31060d Definitions.  
Rule 1060d. The definitions of "building" and "building official" in section 202  
of the code are amended to read as follows:  
Building. "Building" means a combination of materials, whether portable or fixed,  
forming a structure affording a facility or shelter for use or occupancy by persons,  
animals, or property The term does not include a building incidental to the use for  
agricultural purposes of the land on which the building is located if it is not used in the  
business of retail trade. The term shall be construed as though followed by the words  
"or part or parts of the building and all equipment in the building" unless the context  
clearly requires a different meaning.  
Building Official. "Building official" means the person who is appointed and  
employed by a governmental subdivision, who is charged with the administration  
and enforcement of the state codes specified in R 408.30499 of the Michigan Building  
Code, and who is registered in accordance with the requirements of 1986 PA 54, MCL  
338.2301 to 338.2313.  
History: 2010 AACS.  
R 408.31060e Climate Zones.  
Rule 1060e. Section 301.1 and Tables 301.1 and 301.3(2) of the code are  
amended and Figure 301.1a is added to the code to read as follows:  
301.1 General. Climate zones from figures 301.1, 301.1a or table 301.1 shall be  
used in determining the applicable requirements of this code.  
Page 9  
Page 10  
Page 11  
History: 2010 AACS.  
Editor's Note: An obvious error in R 408.31060e was corrected at the request of the promulgating  
agency, pursuant to Section 56 of 1969 PA 306, as amended by 2000 PA 262, MCL 24.256. The rule  
containing the error was published in Michigan Register, 2010 MR 21. The memorandum requesting  
the correction was published in Michigan Register, 2011 MR 5.  
Page 12  
R 408.31061 Certificate.  
Rule 1061. Section 401.3 of the code is amended to read as follows:  
401.3 Certificate. A permanent certificate shall be posted on or in the electrical  
distribution panel, and shall meet all of the following:  
(a) Be affixed or attached so it does not cover or obstruct the visibility of the circuit  
directory label, service disconnect label, or other required labels.  
(b) Be completed by the builder or registered design professional.  
(c) List the predominant R-values of insulation installed in or on ceiling/roof,  
walls, foundation (slab, basement wall, crawlspace wall and/or floor) and ducts outside  
conditioned spaces and U-factors for fenestration. If there is more than 1 value for each  
component, then the certificate shall list the value covering the largest area.  
(d) List the types and efficiencies of heating, cooling and service water heating  
equipment.  
(e) If a gas-fired unvented room heater, electric furnace, or baseboard electric  
heater is installed in the residence, then the certificate shall list "gas-fired unvented  
room heater," as appropriate. An efficiency shall not be listed for gas-fired unvented  
room heaters, electric furnaces, or electric baseboard heaters.  
History: 1998-2000 AACS; 2008 AACS; 2010 AACS.  
R 408.31062 Fenestration product rating.  
Rule 1062. Section303.1.3 of the code is amended to read as follows:  
303.1.3. Fenestration product rating. U-factors of fenestration products (windows,  
doors and skylights) shall be determined in accordance with NFRC 100 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  
303.1.3(1) or 303.1.3(2).  
Exception: Computer simulations by independent NFRC certified laboratories or  
approval under section 21 of 1972 PA 230, MCL 125.1521 are considered in  
compliance with this section.  
History: 1998-2000 AACS; 2008 AACS; 2010 AACS.  
R 408.31063 Insulation and fenestration criteria.  
Rule 1063. Insulation and fenestration criteria. Table R402.1.1 of the code is  
amended to read as follows:  
Page 13  
TABLE R 402.1.1  
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa  
SLAB d CRAWL  
R-  
SPACEc  
FLOOR BASEMENTc VALUE WALL  
R- WALL R- AND R-  
VALUEg VALUE VALUE  
DEPTH VALUE  
WOOD  
FRAME  
CEILING WALL R- R-  
MASS  
WALL  
SKYLIGHTb  
U-  
FACTOR  
CLIMATE FENESTRATION  
ZONE U-FACTOR  
R-Value  
VALUE  
20 or  
5A  
0.32  
0.55  
0.55  
0.55  
38  
13 + 5f  
20 or 13 +  
5f  
13/17  
15/20  
19/21  
30e  
30e  
38e  
10/13  
15/19  
15/19  
10, 2ft  
10, 4ft  
10, 4ft  
15/19  
15/19  
15/19  
6A  
7
0.32  
0.32  
49  
20 or 13 +  
49  
5f  
a. R-values are minimums. U-factors are maximums. When insulation is installed in a cavity that is less  
than the label or design thickness of the insulation, the installed R-value of the insulation shall not be less than  
the R-values specified in the table.  
b. The fenestration U-factor column excludes skylights.  
c. “15/19” means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity  
insulation at the interior of the basement wall. “15/19” may be met with R-13 cavity insulation on the interior  
of the basement wall plus R-5 continuous insulation on the interior or exterior of the home. “10/13” means R-  
10 continuous insulation on the interior or exterior of the home or R-13 cavity insulation at the interior of the  
basement wall.  
d. R-5 shall be added to the required slab edge R-values for heated slabs.  
e. Or insulation sufficient to fill the framing cavity, R-19 minimum.  
f. First value is cavity insulation, second is continuous insulation or insulated siding, so “13 + 5” means  
R-13 cavity insulation plus R-5 continuous insulation or insulated siding. If structural sheathing covers 40 %  
or less of the exterior, continuous insulation R-value may be reduced by no more than R-3 in the locations  
where structural sheathing is used – to maintain a consistent total sheathing thickness.  
g. The second R-value applies when more than half the insulation is on the interior of the mass wall.  
History: 1998-2000 AACS; 2008 AACS; 2010 AACS; 2015 AACS.  
R 408.31063a Specific insulation requirements (prescriptive).  
Rule 1063a Section R402.2.12 of the code is amended to read as follows.  
R402.2.12. Thermally isolated sunroom insulation. The minimum ceiling insulation  
R-values shall be R-24 in zones 5 to 7. The minimum wall R-value shall be R-13 in all  
zones. New wall or walls separating a sunroom from conditioned space shall meet the  
building thermal envelope requirements.  
History: 2010 AACS; 2015 AACS.  
R 408.301064 Fenestration.  
Rule 1064. Sections 402.3.3 and 402.3.6 of the code are amended to read as  
follows:  
402.3.3 Glazed fenestration exemption. Up to 15 square feet (1.4m2) of glazed  
fenestration per dwelling unit shall be permitted to be exempt from U-factor  
requirements in section 402.1.1. This exemption shall not apply to the U-factor  
alternative approach in section 402.1.3 and the total UA alternative in section  
402.1.4.  
Page 14  
402.3.6. Replacement fenestration. Where some or all of an existing  
fenestration unit is replaced with new fenestration product, including sash and glazing,  
the replacement fenestration unit shall meet the applicable requirements for U-factor  
in table 402.1.1. 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 in Table 402.1.1.  
History: 1998-2000 AACS; 2008 AACS; 2010 AACS.  
R 408.31065 Equivalent U-Factors.  
Rule 1065. Section R402.1.4 and table R402.1.3 of the code are amended to read as  
follows:  
Table R402.1.3  
Equivalent U-Factorsa  
Climate Zone Fenestratio Skylight Ceiling  
Frame  
Mass wall Floor  
Basemen Crawl  
Space  
n
U-  
U-  
Wall U- U-Factor b U-Factor tWall  
U-Factor  
Factor  
Factor  
Factor  
U-Factor Wall  
U-  
Factor  
5A  
6A  
7
0.32  
0.32  
0.32  
0.55  
0.55  
0.55  
0.030  
0.026  
0.026  
0.057  
0.057  
0.057  
0.082  
0.060  
0.057  
0.033  
0.033  
0.028  
0.059  
0.050  
0.050  
0.055  
0.055  
0.055  
a. Nonfenestration U-factors shall be obtained from measurement, calculation, or  
an approved source.  
b. When more than half the insulation is on the interior, the mass wall U-factors  
shall be a maximum of 0.065 in zone 5 and marine 4, and 0.057 in zones 6 and 7.  
R402.1.4 Total UA alternative. If the total building thermal envelope UA (sum of U-  
factor times assembly area) is less than or equal to the total UA resulting from using the  
U-factors in Table R402.1.3 (multiplied by the same assembly area as in the proposed  
building), the building shall be considered in compliance with Table R402.1.1. The UA  
calculation shall be done using a method consistent with the ASHRAE Handbook of  
Fundamentals and shall include the thermal bridging effects of framing materials.  
History: 1998-2000 AACS; 2008 AACS; 2010 AACS; 2015 AACS.  
R 408.31066 Systems  
Rule 1066. Sections R403.2.1, R403.2.2, R403.4, and R403.4.2 of the code are  
amended to read as follows:  
R403.2.1. Insulation (prescriptive). All portions of the air distribution system shall  
be installed in accordance with section M1601 and be insulated to an installed R-6 when  
system components are located within the building but outside the conditioned space, and  
R-8 when located outside to the building. When located within a building envelope  
assembly, at least R-8 shall be applied between the duct and that portion of the assembly  
farthest from conditioned space.  
Exception: Portions of the air distribution system within appliances or equipment.  
Page 15  
R403.2.2. Sealing (mandatory). 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 may be applied without additional joint  
seals.  
2. Where a duct connection is made that is partially inaccessible, 3 screws or rivets  
shall be equally spaced on the exposed portion of the joint so as to prevent a hinge  
effect.  
3. Continuously welded and locking-type longitudinal joints and seams in ducts  
operating at static pressures less than 2 inches of water column (500 Pa) pressure  
classification shall not require additional closure systems.  
Duct tightness shall be verified by either of the following:  
1. Post construction test: Total leakage to the outside of a conditioned space or  
total leakage shall be less than or equal to 4 cfm (113.3 L/min) per 100 square feet (9.29  
m2) of conditioned floor area when tested at a pressure differential of 0.1 inches w. g.  
(25 Pa) across the entire system, including the manufacturer’s air handler enclosure. All  
register boots shall be taped or otherwise sealed during the test.  
2. Rough-in test: Total leakage shall be less than or equal to 4 cfm (113.3 L/min)  
per 100 square feet (9.29 m2) of conditioned floor area when tested at a pressure  
differential of 0.1 inches w.g. (25 Pa) across the system, including the manufacturer’s air  
handler enclosure. All registers shall be taped or otherwise sealed during the test. If the  
air handler is not installed at the time of the test, total leakage shall be less than or equal  
to 3 cfm (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.  
Exception: The total leakage test is not required for ducts and air handlers located  
entirely within the building thermal envelope.  
R403.4.1. Circulating hot water systems (mandatory). All circulating service hot  
water piping shall be insulated to at least R-2. Circulating hot water systems shall  
include an automatic or readily accessible manual switch that can turn off the hot water  
circulating pump when the system is not in use.  
Exceptions:  
1. Factory-installed piping within HVAC equipment tested and rated in accordance  
with a test procedure referenced by this code.  
2. Runout piping not exceeding 4 feet (1 219 mm) in length and 1 inch (25 mm) in  
diameter between the control valve and HVAC coil.  
R403.4.2. Hot water pipe insulation (prescriptive). Insulation for hot water pipe  
with a minimum thermal resistance (R-value) of R-3 shall be applied to the following:  
1. Piping larger than 3/4 inch (19.05 mm) nominal diameter.  
2. Piping serving more than 1 dwelling unit.  
3. Piping located outside the conditioned space.  
4. Piping from the water heater to a distribution manifold.  
5. Piping located under a floor slab.  
6. Buried piping.  
7. Supply and return piping in recirculation systems other than demand recirculation  
systems.  
History: 1998-2000 AACS; 2008 AACS; 2010 AACS; 2015 AACS.  
Page 16  
R 408.31069 Air leakage.  
Rule 1069.  
Sections R402.4, R402.4.1, R402.4.1.1, R402.4.1.2, R402.4.2,  
R402.4.3, R402.4.4, and Table R402.4.1.1 of the code are amended to read as follows:  
R402.4 Air leakage. 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. The building thermal envelope shall comply  
with Sections R402.4.1.1 and R402.4.1.2.  
R402.4.1.1. Installation (mandatory). 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. The sealing methods between dissimilar materials shall  
allow for differential expansion and contraction.  
R402.4.1.2. Testing (prescriptive). The building or dwelling unit shall be tested and  
verified as having an air leakage rate of not exceeding 4 air changes per hour. Testing  
shall be conducted with a blower door at a pressure of 0.2 inches (5.08 mm) w.g. (50  
pascals). Where required by the code official, testing shall be conducted by a certified  
independent third party. Certification programs shall be approved by the state  
construction code commission. A written report of the results of the test shall be signed  
by the party conducting the test and provided to the code official. Testing shall be  
performed at any time after creation of all penetrations of the building thermal envelope.  
All of the following apply during testing:  
1. Exterior windows, doors, and fireplace and stove doors shall be closed, but not  
sealed, beyond the intended weatherstripping or other infiltration control measures.  
2. Dampers including exhaust, intake, makeup air, backdraft, and flue dampers shall  
be closed, but not sealed beyond intended infiltration control measures.  
3. Interior doors, installed at the time of the test, shall be open.  
4. Exterior doors for continuous ventilation systems and heat recovery ventilators  
shall be closed and sealed.  
5. Heating and cooling systems, if installed at the time of the test, shall be turned  
off.  
6. Supply and return registers, if installed at the time of the test, shall be fully open.  
R402.4.2. Fireplaces (mandatory). New wood-burning masonry fireplaces shall  
have tight-fitting flue dampers and outdoor combustion air.  
R402.4.3. Fenestration air leakage (mandatory). Windows, skylights, and sliding  
glass doors shall have an air infiltration rate of no more than 0.3 cfm per square foot (1.5  
L/s/m2), and swinging doors no more than 0.5 cfm per square foot (2.6 L/s/m2), when  
tested according to NFRC 400 or AAMA/WDMA/CSA 101/I.S.2/A440 by an accredited,  
independent laboratory and listed and labeled by the manufacturer.  
Exception: Site-built windows, skylights, and doors.  
R402.4.4. Recessed lighting (mandatory). 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.  
Page 17  
TABLE R402.4.1.1  
AIR BARRIER AND INSULATION INSTALLATION  
COMPONENT  
Air barrier and thermal barrier  
CRITERIAa  
A continuous air barrier shall be installed in the  
building envelope.  
Exterior thermal envelope contains a continuous air  
barrier.  
Breaks or joints in the air barrier shall be sealed.  
Air-permeable insulation shall not be used as a  
sealing material.  
Ceiling/attic  
Walls  
The air barrier in any dropped ceiling/soffit shall be  
aligned with the insulation and any gaps in the air  
barrier sealed.  
Access openings, drop down stair, or knee wall  
doors to unconditioned attic spaces shall be sealed.  
Corners and headers shall be insulated and the  
junction of the foundation and sill plate shall be  
sealed.  
The junction of the top plate and top of exterior  
walls shall be sealed.  
Exterior thermal envelope insulation for framed  
walls shall be installed in substantial contact and  
continuous alignment with the air barrier.  
Knee walls shall be sealed.  
Windows, skylights and doors  
Rim joists  
The space between window/door jambs and framing  
and skylights and framing shall be sealed.  
Rim joists shall be insulated and include the air  
barrier.  
Floors  
Insulation shall be installed to maintain permanent  
contact with underside of subfloor decking.  
The air barrier shall be installed at any exposed  
edge of insulation.  
(including above-garage, and cantilevered floors)  
Crawl space walls  
Where provided in lieu of floor insulation,  
insulation shall be permanently attached to the  
crawlspace walls.  
Exposed earth in unvented crawl spaces shall be  
covered with a Class I vapor retarder with  
overlapping joints taped.  
Shafts, penetrations  
Narrow cavities  
Duct shafts, utility penetrations, and flue shafts  
opening to exterior or unconditioned space shall be  
sealed.  
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.  
Garage separation  
Recessed lighting  
Air sealing shall be provided between the garage  
and conditioned spaces.  
Recessed light fixtures installed in the building  
thermal envelope shall be air tight, IC rated, and  
sealed to the drywall.  
Plumbing and wiring  
Batt insulation shall be cut neatly to fit around  
wiring and plumbing in exterior walls, or insulation  
that on installation readily conforms to available  
space shall extend behind piping and wiring.  
Page 18  
Shower/tub on exterior wall  
Electrical/phone box on exterior walls  
HVAC register boots  
Exterior walls adjacent to showers and tubs shall be  
insulated and the air barrier installed separating  
them from the showers and tubs.  
The air barrier shall be installed behind electrical or  
communication boxes or air-sealed boxes shall be  
installed.  
HVAC register boots that penetrate building  
thermal envelope shall be sealed to the subfloor or  
drywall.  
Fireplace  
An air barrier shall be installed on fireplace walls.  
a. In addition, inspection of log walls shall be in accordance with the provisions of ICC-  
400.  
History: 2008 AACS; 2010 AACS; 2015 AACS.  
R 408.31070 Steel-frame ceilings, walls, and floors.  
Rule 1070. Section R402.2.6 of the code are amended to read as follows:  
R402.2.6. Steel-frame ceilings, walls, and floors. Steel-frame ceilings, walls, and  
floors shall meet the insulation requirements of table R402.2.6 or shall meet the U-factor  
requirements in table R402.1.3. The calculation of the U-factor for a steel-frame  
envelope assembly shall use a series-parallel path calculation method.  
History: 1998-2000 AACS; 2003 AACS; 2008 AACS; 2010 AACS; 2015 AACS.  
R408.31071 Simulated performance alternative.  
Rule 1071. Table R405.5.2(1) of the code is amended to read as follows:  
BUILDING COMPONENT  
Above-grade walls  
STANDARD REFERENCE  
DESIGN  
PROPOSED DESIGN  
Type: mass wall if proposed wall is  
mass; otherwise wood frame.  
Gross area: same as proposed  
U-factor: from Table 402.1.3  
Solar absorptance = 0.75  
Remittance = 0.90  
As proposed  
As proposed  
As proposed  
As proposed  
As proposed  
As proposed &n