PDFWAC 51-11C-402300

Table C402.4Building envelope requirementsFenestration.

Table C402.4
Building Envelope Fenestration Maximum U-factor and SHGC Requirements
CLIMATE ZONE
5 AND MARINE 4
U-factor for Class AW windows rated in accordance with AAMA/CSA101/I.S.2/A440, vertical curtain walls and site-built fenestration productsa
FixedbU-factor
U-0.34
OperablecU-factor
U-0.36
Entrance doorsd
U-factor
U-0.60
U-factor for all other vertical fenestration
Fixed U-factor
U-0.26
Operable or mulled windows with fixed and operable sections U-factor
U-0.28
SHGC for all vertical fenestrationf
 
Fixed
Operable
PF < 0.2
0.38
0.33
0.2 ≤ PF < 0.5
0.46
0.40
PF ≥ 0.5
0.61
0.53
Skylights
U-factor
U-0.50
SHGC
0.35
a
U-factor and SHGC shall be rated in accordance with NFRC 100.
b
"Fixed" includes curtain wall, storefront, picture windows, and other fixed windows.
c
"Operable" includes openable fenestration products other than "entrance doors."
d
"Entrance door" includes glazed swinging entrance doors. Other doors which are not entrance doors, including sliding glass doors, are considered "operable."
e
Reserved.
f
Fenestration that is entirely within the conditioned space or is between conditioned and other enclosed space is exempt from solar heat gain coefficient requirements and not included in the SHGC calculation.
[Statutory Authority: RCW 19.27A.045 and chapter 19.27A RCW. WSR 24-16-145, § 51-11C-402300, filed 8/7/24, effective 9/7/24. Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapters 19.27A and 19.27 RCW. WSR 22-14-091, 23-12-101, and 23-20-021, § 51-11C-402300, filed 7/1/22, 6/7/23, and 9/25/23, effective 3/15/24. Statutory Authority: RCW 19.27A.020, 19.27A.025, 19.27A.160 and chapter 19.27 RCW. WSR 19-24-040, § 51-11C-402300, filed 11/26/19, effective 7/1/20. Statutory Authority: RCW 19.27A.025, 19.27A.160, and 19.27.074. WSR 16-03-072, § 51-11C-402300, filed 1/19/16, effective 7/1/16. Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-402300, filed 2/1/13, effective 7/1/13.]