The code, based on New Buildings Institute’s Core Performance protocol, was designed to reduce energy use by 30 percent and cut carbon emissions by 40 percent. Upon passing, municipalities in the commonwealth were able to choose whether to adopt the code as a more energy-efficient alternative to the base energy code. The Core Performance basic requirements in the stretch code include efficiency standards for measures such as window performance, lighting controls, mechanical equipment efficiency and demand-control ventilation. Local government entities could go further and adopt up to 14 measures described in Core Performance as “enhanced performance strategies.”