Building Science Corporation
November 14, 2011

This retrofit house is located in Milton, MA (Cold Climate). It involved replacing the asphalt shingles on the roof and adding 8” closed-cell spray foam insulation in the rafter cavities. The walls were retrofitted to add two 2” layers of foil-faced polyisocyanurate rigid insulation to the exterior of the existing wall sheathing. The existing fiberglass batt or cellulose insulation in the framing cavities was left in place. The windows were replaced with new triple-glazed windows. Closed-cell spray foam insulation was added to the interior of the existing rim joist and foundation wall, and 2” XPS rigid insulation was added above the existing slab.

Enclosure Design


For complete details on this deep energy retrofit project, go to:
National Grid Deep Energy Retrofit Pilot Program—1960s Garrison Colonial Comprehensive Retrofit