Radiance Cohousing is a nine-unit cohousing complex made up of two buildings—one with four and one with five units—that face onto a common courtyard and garden.
The project was initiated in 2012 by a small group of people who pooled their resources, formed a development company, and worked together to plan and manage the development of their own homes. Construction was completed in the fall of 2018.
The cohousing group worked closely with BLDG Studio to develop the overall plan and then customize the individual units, which range in size from 72 to 112 square metres. “There are a few standard footprints, but everyone could shape the interior walls to suit their needs,” says engineer and Passive House Consultant Michael Nemeth of Bright Buildings, who lives with his partner, Shannon, in one of the units. One unit was designed as a common gathering space for meetings, birthday parties, and the like.
Cohousing attracts people who want a housing model that embraces community, and often sustainability as well. Says Nemeth, “For us that sustainability goal was Passive House.”
As the climate is quite chilly in Saskatoon, regularly veering down to –30°C, the wall assemblies were heavily insulated, attaining an overall R-value of 60. The complex was part of a Canada-wide pilot for the use of wood fibre insulation—28 cm of it in this project—exterior to 2 x 6 walls insulated with mineral wool batts. This wall assembly had the merit of simplicity, with long stainless steel screws affixing a 2 x 4 rain screen to the wood fibreboard. The final layer, fibre cement siding, was chosen for its durability.
Passive House-certified windows, the larger ones placed strategically on the south façades in both buildings, completed these assemblies. Nemeth noticed and deeply appreciated the significant solar gain the windows admitted throughout the winter.
Passive House Consultant and Mechanical Design
The roof assembly achieves an R-100 with blown-in cellulose. The foundation has 30 cm of EPS under a slab-on-grade.
Each unit is serviced by its own ERV for constant fresh air. A centralized air source heat pump system offers heating and cooling for all the units.
Radiance Cohousing incorporates a variety of other environmental features, including rainwater harvesting, a 38-kW PV array owned by the SES Solar Cooperative, and a shared electric vehicle provided by the Saskatoon Carshare Cooperative. By combining cohousing with environmental design, this project showcases what’s possible in terms of quality homes that build community and respond to a changing climate.
PASSIVE HOUSE METRICS
Cooling and dehumidification demand
Primary energy renewable (PER)