This Passive House retrofit is the first certified Passive House project in NYC and a winner in the 2014 International Passive House Design Awards. The retrofit adds a new rear facade, 3rd floor, and roof terrace. A continuous envelope of insulation, air tightness, and mitigated thermal bridges will reduce energy usage. Passive Houses consume approximately 90% less heat energy than the average home and 75% less energy overall.The project features high performance materials and a HRV ventilation system. The third floor addition has an angled roof with solar thermal and photovoltaic panels. There is no gas service. All lighting is LED or fluorescent. Internal stair volumes bring natural light into the middle of the building with perforated metal stairs and glass panels.