WAC 51-11C-61041. Section A104.1 — General

A104.1 General. Table A104.1 lists heat loss coefficients for below-grade walls and floors. Coefficients for below-grade walls are given as U-factors (Btu/h • ft 2 • °F of wall area). Coefficients for below-grade slabs are listed as F-factors (Btu/h • ft • °F per lineal foot of slab perimeter). Below-grade wall U-factors are only valid when used with the accompanying below-grade slab F-factor, and vice versa. Table A104.1 Default Wall U-factors and Slab F-factors for Basements Below Grade Wall U-factor Below Grade Slab F-factor 2 Foot Depth Below Grade Uninsulated 0.331 0.58 R-11 Interior 0.063 0.67 R-11 Interior w/TB 0.065 0.59 R-19 Interior 0.042 0.68 R-19 Interior w/TB 0.045 0.59 R-21 Interior 0.040 0.68 R-21 Interior w/TB 0.042 0.59 R-21+R-5 ci Interior 0.031 0.68 R-21+R-5 Interior w/TB 0.032 0.59 R-21 plus R-7 ci Interior 0.029 0.68 R-21+R-7 Interior w/TB 0.030 0.59 R-10 Exterior 0.089 0.56 R-12 Exterior 0.061 0.60 3.5 Foot Depth Below Grade Uninsulated 0.271 0.51 R-11 Interior 0.058 0.61 R-11 Interior w/TB 0.061 0.55 R-19 Interior 0.041 0.62 R-19 Interior w/TB 0.042 0.55 R-21 Interior 0.038 0.63 R-21 Interior w/TB 0.040 0.56 R-21+R-5 Interior 0.030 0.632 R-21+R-5 Interior w/TB 0.031 0.56 R-21 plus R-7 ci 0.027 0.63 R-21 plus R-7 ci w/TB 0.029 0.56 R-10 Exterior 0.075 0.52 R-12 Exterior 0.057 0.57 7 Foot Depth Below Grade Uninsulated 0.185 0.43 R-11 Interior 0.051 0.541 R-11 Interior w/TB 0.053 0.49 R-19 Interior 0.036 0.54 R-19 Interior w/TB 0.037 0.50 R-21 Interior 0.035 0.56 R-21 Interior w/TB 0.035 0.50 R-21+R-5 Interior 0.027 0.56 R-21+R-5 Interior w/TB 0.028 0.51 R-21+R-7 Interior 0.025 0.57 R-21+R-7 Interior w/TB 0.026 0.51 R-10 Exterior 0.058 0.47 R-12 Exterior 0.050 0.42 Below Grade Wall U-factor Below Grade Slab F-factor 2 Foot Depth Below Grade Uninsulated 0.331 0.58 R-11 Interior 0.063 0.67 R-11 Interior w/TB 0.065 0.59 R-19 Interior 0.042 0.68 R-19 Interior w/TB 0.045 0.59 R-21 Interior 0.040 0.68 R-21 Interior w/TB 0.042 0.59 R-21+R-5 ci Interior 0.031 0.68 R-21+R-5 Interior w/TB 0.032 0.59 R-21 plus R-7 ci Interior 0.029 0.68 R-21+R-7 Interior w/TB 0.030 0.59 R-10 Exterior 0.089 0.56 R-12 Exterior 0.061 0.60 3.5 Foot Depth Below Grade Uninsulated 0.271 0.51 R-11 Interior 0.058 0.61 R-11 Interior w/TB 0.061 0.55 R-19 Interior 0.041 0.62 R-19 Interior w/TB 0.042 0.55 R-21 Interior 0.038 0.63 R-21 Interior w/TB 0.040 0.56 R-21+R-5 Interior 0.030 0.632 R-21+R-5 Interior w/TB 0.031 0.56 R-21 plus R-7 ci 0.027 0.63 R-21 plus R-7 ci w/TB 0.029 0.56 R-10 Exterior 0.075 0.52 R-12 Exterior 0.057 0.57 7 Foot Depth Below Grade Uninsulated 0.185 0.43 R-11 Interior 0.051 0.541 R-11 Interior w/TB 0.053 0.49 R-19 Interior 0.036 0.54 R-19 Interior w/TB 0.037 0.50 R-21 Interior 0.035 0.56 R-21 Interior w/TB 0.035 0.50 R-21+R-5 Interior 0.027 0.56 R-21+R-5 Interior w/TB 0.028 0.51 R-21+R-7 Interior 0.025 0.57 R-21+R-7 Interior w/TB 0.026 0.51 R-10 Exterior 0.058 0.47 R-12 Exterior 0.050 0.42 TB = R-5 Thermal Break TB = R-5 Thermal Break