11 Crown – Passive House Development

Project Background:

The 11 Crown development includes a four-story multifamily building with 63 affordable housing units; amenity, office, and retail spaces; and an attached parking garage. Two additional buildings ascend the steep slope of the site and contain 18 three-story townhouses. All buildings were designed to the Passive House standard.

The four-story building meets Passive House requirements with less insulation than the townhomes due to higher density and internal heat gains. The other buildings have a greater exterior surface-area-to-volume ratio and a lower density of occupants, appliances, and plug loads, resulting in fewer beneficial internal gains in the winter. The four-story multifamily building achieved certification under the PHIUS+ program, while the remaining two buildings fell short only under the strict Passive House requirements for air infiltration testing.

Each residential unit is provided heating and cooling from ducted, air-source heat pumps; hot water from natural gas, tankless heaters; and ventilation from in-unit Zehnder energy recovery ventilators (ERVs). Challenges with the verification process included testing the ERVs where intake and exhaust was only accessible on the building’s exterior.