Built in 1934 to a design by Barry Byrne, this poured-concrete house had cracked and weathered badly, but its form was well worth saving. In 2011 it was renovated to Passive House and became the first PHI-certified retrofit in Connecticut.
The whole house is wrapped on the outside in 10 inches of insulation made from recycled glass, chosen to avoid petroleum-based and toxic materials.
Solar thermal panels make hot water, with a heat pump water heater as backup. That hot water feeds a small radiant floor and a heater after the energy-recovery ventilator. A 1-ton heat pump cools and dries the air in summer and is almost never needed for heat.