The world’s first Passive House car dealership is opening its doors in Red Deer, Alberta. The new Scott Subaru dealership building is divided into three zones: a showroom, a repair shop, and a car drop-off zone.
Each of these zones presented a set of challenges from a Passive House performance perspective. And as this dealership was the very first of its kind, there was no reference to fall back on. The solutions required an exceptionally strong and creative team effort, starting with design and modelling initiatives and carrying all the way through to the implementation of these ideas by the builder.
“We were excited to have the opportunity to build the first-ever Passive House car dealership in the world for Scott Subaru,” says Ron Goss of Black Creek Developments out of Sylvan Lake, Alberta. “The experience has been a lot more complex than we initially anticipated. The key to the Passive House building process was precise execution of the small details.” Goss adds, “Since Passive House is not a standard building practice in North America, we encountered many obstacles during construction that required innovative solutions.”
The initial roadblock to overcome was the corporate design guideline that dictated that 65% of the west-facing storefront be glazing. Various measures were explored to mitigate the predicted solar gains, but the only ones deemed feasible were insulated spandrel panels in the top row of glazing and automated operable internal blinds with manual override.
Passive House Consultant
Passive House Building Certifier
However, PHPP modelling by Peel Passive House Consulting showed that these measures would be insufficient to mitigate the inevitable high cooling load. The team decided that the load would be best met by a ducted variable refrigerant flow system. Electric-resistance coils were installed in the supply air of each indoor unit to provide heat during peak heating conditions, when the heat pumps are expected to stop operating due to the very low temperatures.
Another particularly challenging HVAC question was how to remove the car exhaust, which contains harmful pollutants, from the service bays. To meet code requirements, each of the six service bays requires 680 m3h (400 CFM) of exhaust. Normally, all bays are connected to the same exhaust fan—which means that all bays are exhausted even when only one bay is in use—but modelling revealed excessive heat losses with the exhaust flows if this standard practice were implemented. For this project, each bay was instead separately vented, cutting the exhaust rate by 83%.
Finding the right building envelope components also took a team effort, particularly the massive overhead doors required for the shop areas and the large curtain wall in the showroom area, which is part of the aesthetic of the car dealership. Peel Passive House was able to find solutions with products sourced from German manufacturers; however, when ordering products from Europe, it is important to be aware of the extended lead times.
The team faced another challenge when local engineering and building inspectors were reluctant to accept Passive House standards and technologies. “There was some scepticism as to whether the system would actually work,” Goss explains. “We are proving these suspicions are unwarranted, as everything is working just the way the system was designed.”
PASSIVE HOUSE METRICS
Cooling and dehumidification demand
Primary energy renewable (PER)
Feature Photo by Kevin Clark, Black Creek Developments