Wash. Admin. Code § 51-11R-30314 - Table R303.1. 3(4)-Default U-factors for skylights

TABLE R303.1. 3(4) DEFAULT U-FACTORS FOR SKYLIGHTS

Fenestration Type	Frame Type
	Aluminum Without Thermal Break	Aluminum With Thermal Break	Reinforced Vinyl/Aluminum-Clad Wood or Vinyl	Wood or Vinyl-Clad Wood/Vinyl Without Reinforcing
Single Glazing glass acrylic/polycarb	U-1.58 U-1.52	U-1.51 U-1.45	U-1.40 U-1.34	U-1.18 U-1.11
Double Glazing air argon	U-1.05 U-1.02	U-0.89 U-0.86	U-0.84 U-0.80	U-0.67 U-0.64
Double Glazing, e = 0.20
air	U-0.96	U-0.80	U-0.75	U-0.59
argon	U-0.91	U-0.75	U-0.70	U-0.54
Double Glazing, e = 0.10
air	U-0.94	U-0.79	U-0.74	U-0.58
argon	U-0.89	U-0.73	U-0.68	U-0.52
Double Glazing, e = 0.05
air	U-0.93	U-0.78	U-0.73	U-0.56
argon	U-0.87	U-0.71	U-0.66	U-0.50
Triple Glazing
air	U-0.90	U-0.70	U-0.67	U-0.51
argon	U-0.87	U-0.69	U-0.64	U-0.48
Triple Glazing, e = 0.20
air	U-0.86	U-0.68	U-0.63	U-0.47
argon	U-0.82	U-0.63	U-0.59	U-0.43
Triple Glazing, e = 0.20 on 2 surfaces
air	U-0.82	U-0.64	U-0.60	U-0.44
argon	U-0.79	U-0.60	U-0.56	U-0.40
Triple Glazing, e = 0.10 on 2 surfaces
air	U-0.81	U-0.62	U-0.58	U-0.42
argon	U-0.77	U-0.58	U-0.54	U-0.38
Quadruple Glazing, e = 0.10 on 2 surfaces
air	U-0.78	U-0.59	U-0.55	U-0.39
argon	U-0.74	U-0.56	U-0.52	U-0.36
krypton	U-0.70	U-0.52	U-0.48	U-0.32

Notes for Table R303.1. 3(4)

1. U-factors are applicable to glass and plastic, flat and domed units, all spacers and gaps.

2. Emissivities shall be less than or equal to the value specified.

3. Gap fill shall be assumed to be air unless there is a minimum of 90% argon or krypton.

4. Aluminum frame with thermal break is as defined in footnote 1 to Table R303.1. 3(1).

Notes

Wash. Admin. Code § 51-11R-30314

Amended by WSR 20-21-081, Filed 10/19/2020, effective 2/1/2021

Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. 13-04-055, § 51-11R-30314, filed 2/1/13, effective 7/1/13.