Seattle’s 1st Passive House apartment building opens in Columbia City

Pax Futura, the first Passive House apartment building to be constructed in Seattle, opened its doors this month, marking an important milestone in the development of the high performance building market in the Emerald City. 

The brainchild of owner and builder Sloan Ritchie of Cascade Built, the project will be certified by PHIUS (Passive House Institute US). The project was the first to join the 20 by 2020 Building Challenge, a local campaign to promote the development of 20 Passive House or net zero energy projects of 20,000 square feet or larger in King County by the year 2020.

Photography by Vivian Hsu

The building, designed by NK Architects, includes 35 compact units and a commercial space in its 20,100 square feet. Located in the heart of the hip Columbia City neighborhood, just blocks away from the light rail station, the building is a model of the kind of affordable, low carbon, urban living our cities need today.

The building’s Passive House envelope was constructed by Cascade Built using SIPs (structural insulated panels). Domestic hot water is provided by an innovative system that couples solar thermal collectors with a gas boiler backup. The building’s balanced, filtered, heat recovery ventilation system ensures excellent indoor air quality throughout the year. During the summer and winter months, heat pumps contributed additional cooling and heating to incoming air.

Occupant-operated sliding exterior shades on the western façade engage residents in the thermal performance of the building, allowing them to shade their units from late afternoon sun.

Sloan estimates the incremental cost of achieving Passive House performance (compared to Seattle energy code) at just 5%. He expects that the lessons learned on this project will allow him to deliver his next Passive House building at closer to 2-3% cost “premium”. This modest cost delta for Passive House performance will slash energy use by 50% compared to a code-minimum building, reduce maintenance costs, and create happier tenants (and therefore lower vacancy rates) thanks to superior comfort and clean air.

Pax Futura is proof positive that Passive House buildings make economic sense, and we were honored to work on the project with Sloan and his team. Kudos to Cascade Built!