Aspects of the Zero Energy Home System:
Building Envelope
Ceiling, wall, floor, and slab insulation shall meet or exceed the 2015 International Energy Conservation Code (IECC) levels.
Fenestration must meet ENERGY STAR Requirements. The home should use high-performance windows that meet ENERGY STAR v5.0 and v6.0 specification.
ENERGY STAR Window Specs Required for Zero Energy Ready Home Projects. Massachusetts is in climate zone 5 (energy.gov).