Codes & Standards

ASHRAE 90.1 – 2007 (90.1 ASHRAE 2004)
Climate Zone	Roof (Conditioned)		Roof (Semi-Heated)		Walls (Conditioned)		Walls (Semi-Heated)
Climate Zone	Performance	Prescriptive	Performance	Prescriptive	Performance	Prescriptive	Performance	Prescriptive
1	0.065^a	R-19	1.280	NR	0.113	R-13	1.180	NR
2	0.065^a	R-19	0.167	R-6	0.113	R-13	0.184	R-6
3	0.065^a	R-19	0.097	R-10	0.113	R-13	0.184	R-6
4	0.065	R-19	0.097	R-10	0.113	R-13	0.134	R-10
5	0.065	R-19	0.097	R-10	0.113	R-13	0.123	R-11
6	0.065	R-19	0.097	R-10	0.113	R-13	0.113	R-13
7	0.065	R-19	0.097	R-10	0.057	R-13 + R-13	0.113	R-13
8	0.049	R-13 + R-19	0.072	R-16	0.057	R-13 + R-13	0.113	R-13

Climate Zones 1-8 are standing seam roofs with a 1″ thick thermal spacer block. NR=No Requirement
a. For Metal Building roof panels installed directly above conditioned paces that are not cooled, where the exterior surface has a Solar Reflectance of 0.70 and a minimum Thermal Emittance of 0.75 or a Solar Reflectance Index of 82, the roof insulation shall comply with a maximum U-Factor of 0.084 for Climate Zone 1, U-Factor of 0.078 for Climate Zone 2, and a U-Factor of 0.076 for Climate Zone 3

ASHRAE 90.1 – 2010 (90.1 – 2007 addendum g)
Climate Zone	Roof (Conditioned)		Roof (Semi-Heated)		Walls (Conditioned)		Walls (Semi-Heated)
Climate Zone	Performance	Prescriptive	Performance	Prescriptive	Performance	Prescriptive	Performance	Prescriptive
1	0.065^a	R-19	0.167	R-6	0.093	R-16	0.113	R-13
2	0.055^a	R-13 + R-13	0.097	R-10	0.093	R-16	0.113	R-13
3	0.055^a	R-13 + R-13	0.097	R-10	0.084	R-19	0.113	R-13
4	0.055	R-13 + R-13	0.097	R-10	0.084	R-19	0.113	R-13
5	0.055	R-13 + R-13	0.083	R-13	0.069	R-13 + R-5.6 ci	0.113	R-13
6	0.049	R-13 + R-19	0.072	R-16	0.069	R-13 + R-5.6 ci	0.113	R-13
7	0.049	R-13 + R-19	0.072	R-16	0.057	R-13 + R-5.6 ci	0.113	R-13
8	0.035	R-11 + R-19 LS	0.065	R-19	0.057	R-13 + R-5.6 ci	0.113	R-13

Climate Zones 1-8 are standing seam roofs with a minimum R-3.5 thermal spacer block. L=Liner System, ci=Continuous Insulation
a. Metal Building roof panels installed directly above cooled conditioned spaces in Climate Zone 1, shall comply with a minimum 3-year aged Solar Reflectance of 0.55 and a minimum 3-year aged Thermal Emittance of 0.75 or a
minimum 3-year aged Solar Reflectance Index of 64, if not, the roof insulation must be increased by installing a system with a maximum U-Factor of 0.028.

ASHRAE 90.1 – 2013, 2016, 2019 & 2022
Climate Zone	Roof (Conditioned)		Roof (Semi-Heated)		Walls (Conditioned)		Walls (Semi-Heated)
Climate Zone	Performance	Prescriptive	Performance	Prescriptive	Performance	Prescriptive	Performance	Prescriptive
0 & 1*	0.041^a	R-10 + R-19 FC	0.115	R-10	0.094	R-0 + R-9.8 ci	0.352	NR
2	0.041^a	R-10 + R-19 FC	0.096	R-16	0.094	R-0 + R-9.8 ci	0.162	R-13
3	0.041^a	R-10 + R-19 FC	0.096	R-16	0.094	R-0 + R-9.8 ci	0.162	R-13
4	0.037	R-19 + R-11 LS or R-25 + R-8 LS	0.082	R-19	0.060	R-0 + R-15.8 ci	0.162	R-13
5	0.037	R-19 + R-11 LS or R-25 + R-8 LS	0.082	R-19	0.050	R-0 + R-19.0 ci	0.094	R-0 + R-9.8 ci
6	0.031	R–25 + R-11 LS	0.060	R-19 + R-19	0.050	R-0 + R-19.0 ci	0.094	R-0 + R-9.8 ci
7	0.029	R- 30 + R-11 LS	0.037	R-19 + R-11 LS or R-25 + R-8 LS	0.044	R-0 + R-22.1 ci	0.072	R-0 + R-13 ci
8	0.026	R-25 + R-11 + R-11 LS	0.037	R-19 + R-11 LS or R-25 + R-8 LS	0.039	R-0 + R-25 ci	0.060	R-0 + R-15.8 ci

Climate Zone 1-8 are standing seam roofs with minimum R-3 thermal spacer block, except for the Filled Cavity (FC) systems which require a minimum R-5 thermal spacer block;
LS = Liner System, ci = Continuous Insulation
a. Metal Building roof panels installed directly above cooled conditioned spaces, shall comply with a minimum 3-year aged Solar Reflectance of 0.55 and a minimum 3-year aged Thermal Emittance of 0.75 or a minimum 3-year aged
Solar Reflectance Index value of 64, if not, the roof insulation must be increased by installing a system with a maximum U-Factor of 0.028.
*Climate Zone 0 was added in 2019.

IECC – 2009
Climate Zone	Roof		Walls
Climate Zone	Performance	Prescriptive	Performance	Prescriptive
1	0.065	R-19	0.093	R-16
2	0.055	R-13 + R-13	0.093	R-16
3	0.055	R-13 + R-13	0.084	R-19
4	0.055	R-13 + R-13	0.084	R-19
5	0.055	R-13 + R-13	0.069	R-13 + R-5.6 ci
6	0.049	R-13 + R-19	0.069	R-13 + R-5.6 ci
7	0.049	R-13 + R-19	0.057	R-19 + R-5.6 ci
8	0.035	R-11 + R-19	0.057	R-19 + R-5.6 ci

LS = Liner System, ci = Continuous Insulation
Roof assemblies are based on a standing seam roof with an R-5 thermal spacer block.

IECC – 2012, 2015 & 2018
Climate Zone	Roof		Walls
Climate Zone	Performance	Prescriptive	Performance	Prescriptive
1	0.035^a,b	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
2	0.035^b	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
3	0.035^b	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
4	0.035	R-19 + R-11 LS	0.052	R-13 + R-13 ci
5	0.035	R-19 + R-11 LS	0.052	R-13 + R-13 ci
6	0.031	R-25 + R-11 LS	0.052	R-13 + R-13 ci
7	0.029	R-30 + R-11 LS	0.052	R-13 + R-13 ci
8	0.029	R-30 + R-11 LS	0.052	R-13 + R-13 ci

LS = Liner System, ci = Continuous Insulation
See Section C402.2.1 for list of exceptions.
a. Climate Zone 1 is a thru-fastened roof without thermal spacer block. Roof assemblies in Climate Zone 2-8 are based on a standing seam roof with a thermal spacer block IECC-2012 = R-5, IECC-2015/
IECC-2018 = R-3.
b. Metal Building roofs with a slope less than 2:12, installed directly above cooled conditioned spaces shall comply with one or more of the following options; 3-year aged Solar Reflective Index of 0.55 and
a 3-year aged Thermal Emittance of 0.75

IECC – 2021
Climate Zone	Roof		Walls
Climate Zone	Performance	Prescriptive	Performance	Prescriptive
0	0.035^a,b	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
1	0.035^b	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
2	0.035^b	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
3	0.035	R-19 + R-11 LS	0.079	R-13 + R-6.5 ci
4	0.035	R-19 + R-11 LS	0.052	R-13 + R-13 ci
5	0.035	R-19 + R-11 LS	0.050	R-13 + R-14 ci
6	0.031	R-25 + R-11 LS	0.050	R-13 + R-14 ci
7	0.029	R-30 + R-11 LS	0.044	R-13 + R-17 ci
8	0.026	R-25 + R-11 + R-11 LS	0.039	R-13 + R-19.5 ci