Project Team

Inspired by issues of global warming, our goal for our new home was to create a comfortable, modern living space that produced more energy than it consumed. We also hoped to produce enough energy to power an electric car to provide the majority of our transportation. And we hoped to do this in a home that would be inviting and that could be built with “green” materials and ambitious, but proven, building techniques.

Of course, we also had aesthetic and other design goals, including aging in place, living exclusively on one floor, if necessary. As the design goals came into focus, we found that design decisions taken for other reasons kept expanding our south-facing roof. So, although great thought and care went into lowering the energy demands of the house, we also saw an opportunity to install a large, grid-tied PV array that would allow us to provide renewable energy back to the grid and reduce carbon emissions beyond what our own house would be saving.

Our goal was not to achieve net-zero by brute force, but to provide as much environmental benefit from our roof as possible. Purchasing an electric car almost as soon as we moved into our house was also a goal.

Our Wheego (the only electric car brand commercially available in our area in 2011) has been our primary source of local transportation since July of 2011. We have driven it over 8000 miles in that time (usually car-pooling to work or errands) and our PV array has provided sufficient power for the house and car with plenty to spare to share with our neighbors and to contribute significant electricity credit to charitable organizations.

Quick Facts


Location Hadley, Massachusetts
Building Type Single-family residence
Project Type
Basis of Performance Claim
Total Cost of Project $809,582

Energy Summary

Energy Data Type
Renewable Energy System Type(s)
Net electricity usage (purchased) -19,634 kWh/year
Annual renewable energy generated 29,944 kWh/year

Envelope and Mechanicals

Subslab assembly

4"Continuous Rigid Foam (Type IX EPS)

Foundation wall assembly

2.5” Continuous Rigid Foam EPS & 5.5” Formaldehyde-free Fiberglass Batts

Above grade wall assembly

11.5” Dense-pack Cellulose

Air Changes per hour, ACH50 0.89 ACH50