For a three-story, 100 000 ft² office building in Denver, Colorado, the (IECC) requires window assemblies to have a minimum U-factor of 0.70 Btu/hr · °F · ft² (for IECC climate zone 5). Convert this U-factor to:
a. The thermal resistance (R-values), in units of hr · °F · ft²/Btu
b. The metric equivalent thermal resistance (RSI), in units of °C · m²/W
c. The metric equivalent U-factor, in units of W/°C · m²