Advances in building envelopes and HVAC equipment enable widespread use of air source heat pumps by many in the "Net Zero Energy" and "Passive House" movements. Steve Bluestone will report on two related items: a three year performance study of an air source heat pump system using hourly measurements (done with Henry Gifford and built above his garage) and the design and construction of his new 101 unit high performance rental building in NYC utilizing the same technology. Each apartment has individual electric metering of each heat pump and will provide minute by minute consumption data in perpetuity. Electricity sub-metering, who pays for the heat, energy consumption data and the regulatory hurdles will be covered in this session. In the end, the goal is to have tenants pay for their own heat, have their rents downwardly adjusted by a fair value, and ultimately, to see the windows stay closed throughout the heating season.