Project Team

Other Team Members

Local builder

This is a rebuild and Deep Energy Retrofit of a 1970's ranch with a full poured cement cellar, with a 1990's addition on concrete piers. The location, within the coastal zone, precluded any expansion of the footprint, but expansion upward was allowed. The original ranch was torn down to the first floor deck, preserving the cellar, and the addition was completely gutted, but left standing. The ranch was rebuilt into a two story house with SIPs, the addition was insulated, top, sides and bottom, with exterior nail base SIPs and interior fiberglass and the cellar was sealed with spray foam, foam panels and fiberglass. High efficiency windows, ventillation, minisplits, HP water heater, energy star appliances, LEDs and a monitored 5.36 KW PV system complete the package. The house is totally electric, and has a Net electric meter, tied to the grid. The HERS rating is 22.

Quick Facts


Location Edgartown, Massachusetts
Building Type Single family residence
Project Type Zero Energy Ready / Near Zero Energy
Basis of Performance Claim Modeled, Verified
Bedrooms 4
Bathrooms 3.5
Conditioned Floor Area 2,700 sq ft
Total Cost of Project $1,000,000

Energy Summary

Energy Data Type Modeled, Verified
Renewable Energy System Type(s) Photovoltaics
HERS Index 22
Net electricity usage (purchased) 2,910 kWh/year
Annual renewable energy generated 7,741 kWh/year

Envelope and Mechanicals

Subslab assembly

slab was pre-existing poured concrete. Was insulaed with 2 inches of foam panels covered with 1.5 inches plywood.

Foundation wall assembly

preexisting poured concrete. Covered with 3 inches of foam panels, 3.5 inches of fiberglass and .75 inches of plywood. Rim joists were spray foamed to 4 inches.

Above grade wall assembly

Same as foundation wall

Door Assembly

Same as windows; 7 full glass doors

Air Changes per hour, ACH50 0.46 ACH50