Located near the heart of downtown Chelsea, 25 Sixth Street is a 62-unit, transit-oriented project for The Neighborhood Developers that will be built on a previously developed site adjacent to the newly constructed MBTA Silver Line station near Bellingham Square. The project is pursuing certification under the PHIUS+ 2018 Passive House standard as well as the MassSave Multifamily Passive House Incentive Program. The design process involves integrated energy modeling to facilitate a robust thermal envelope, uninterrupted air barrier, and high performance glazing that works to minimize energy loss and better control heating and cooling loads. The building’s mechanical equipment includes centralized energy recovery ventilation and cold-climate VRF heat pump systems. Additionally, the building will be made solar ready for future inclusion of photovoltaic arrays to cover a portion of the building’s electrical load.