The purpose of this Chapter is to establish minimum regulations for energy-efficient buildings using prescriptive, performance-based, or energy rating index compliance alternative provisions. The provisions of this code shall regulate the design and construction of building envelopes for adequate thermal resistance and low air leakage, including the design and selection of mechanical systems, service water-heating systems, pools and spas, electrical equipment, power, and lighting systems in order to enhance the efficient use and conservation of energy in new and existing building construction. (Ord. 43-17, 12-19-2017, eff. 1-1-2018; amd. Ord. 42-20, 12-1-2020, eff. 1-1-2021)