Except as provided in *RCW
19.27A.020(7), the Washington state energy code for residential buildings shall be the maximum and minimum energy code for residential buildings in each city, town, and county and shall be enforced by each city, town, and county no later than July 1, 1991. The Washington state energy code for nonresidential buildings shall be the minimum energy code for nonresidential buildings enforced by each city, town, and county.