(Effective until February 1, 2021)

PDFWAC 51-11R-30314

Table R303.1.3(4)—Default U-factors for skylights.

TABLE R303.1.3(4)
DEFAULT U-FACTORS FOR SKYLIGHTS
 
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
Fenestration Type
Single Glazing
 
 
 
 
 
glass
U-1.58
U-1.51
U-1.40
U-1.18
 
acrylic/polycarb
U-1.52
U-1.45
U-1.34
U-1.11
Double Glazing
 
 
 
 
 
air
U-1.05
U-0.89
U-0.84
U-0.67
 
argon
U-1.02
U-0.86
U-0.80
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 both 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).
[Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30314, filed 2/1/13, effective 7/1/13.]
(Effective February 1, 2021)

PDFWAC 51-11R-30314

Table R303.1.3(4)—Default U-factors for skylights.

TABLE R303.1.3(4)
DEFAULT U-FACTORS FOR SKYLIGHTS
 
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
Fenestration Type
Single Glazing
 
 
 
 
 
glass
U-1.58
U-1.51
U-1.40
U-1.18
 
acrylic/polycarb
U-1.52
U-1.45
U-1.34
U-1.11
Double Glazing
 
 
 
 
 
air
U-1.05
U-0.89
U-0.84
U-0.67
 
argon
U-1.02
U-0.86
U-0.80
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).
[Statutory Authority: RCW 19.27A.045 and chapter 19.27A RCW. WSR 20-21-081, § 51-11R-30314, filed 10/19/20, effective 2/1/21. Statutory Authority: RCW 19.27A.020, 19.27A.045 and chapters 19.27 and 34.05 RCW. WSR 13-04-055, § 51-11R-30314, filed 2/1/13, effective 7/1/13.]