Building Science Corporation
February 21, 2012

This retrofit house is located in Gloucester, MA (Cold Climate). It involved adding three layers of 2” polyisocyanurate rigid insulation above the roof deck and netted cellulose 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 and cellulose insulation to the framing cavities. The windows were replaced with triple-glazed windows and open-cell spray foam insulation was added at the rim joist. 2 ½” XPS rigid insulation and 1” polyisocyanurate rigid insulation were added to the interior of the foundation wall and 2” XPS rigid insulation was added over the existing slab with cracks sealed and surface covered with epoxy paint.

Enclosure Design

For complete details on this deep energy retrofit project, go to
National Grid Deep Energy Retrofit Pilot Program—Gloucester Coastal Cottage Retrofit