Passive House and Performance-based Building Codes

Over several years in my early career, I worked for a green building magazine focused on the commercial building world. Around 2006, USGBC’s LEED program was just gaining traction and green building was still considered to be a specialty. In the past decade-plus, however, that has morphed. Today, green is a part of the building conversation, period, and for good reason.

Buildings consume 40 percent of global energy use and contribute up to 30 percent of annual global greenhouse gas emissions, Chris Ballard, CEO of Passive House Canada, said in a presentation during Fenestration Canada’s virtual spring meeting.

As more municipal governments are declaring climate emergencies and navigating how to respond, one avenue could be to implement outcome-based codes, according to Ballard. Characteristics of such performance-based codes could include:

• Designing buildings to achieve specific performance outcomes;
• Moving away from the reference building approach;
• Energy modeling playing a central role;
• Monitoring and verification;
• Building benchmarks and labeling; and
• Regarding fenestration performance and airtightness as critical elements.

Passive House is one certification program that has specific performance targets, said Ballard, explaining that it is all about energy modeling and meeting comfort, air quality and hygiene requirements.

Rather than using a prescriptive approach, it's up to the architect and other project team members to determine the best path toward meeting those performance goals. The buildings are design intensive, put architecture first then concentrate on systems, said Ballard.

Passive House design abides by five principles, according to Ballard:

1. Super insulation
2. Airtight construction
3. Thermal bridge free
4. High quality windows with solar orientation
5. Ventilation system with heat recovery, which Ballard described as "absolutely critical."

The certification process requires testing during construction, as well as a final test to ensure the finished building meets certain standards. Ballard says new construction built to Passive House standards is generally 90 percent more efficient than a comparable building built to standard techniques. Retrofits are 70 percent more efficient, he cited.

Fenestration has an opportunity with Passive House to make a great impact. The standard window in Canada will be triple glazed with a high-performance frame by 2032, said Ballard. He referenced several potential impacts on the fenestration industry. For one, high performance builders value better products. And, projects will need to dedicate a larger share of the budget for fenestration. Ballard said that, although the total square footage of glass might be reduced in a building designed to Passive House standards, the cost of the better-performing glass could be higher.

“If the government is mandating this move to high-performance building standards, then governments needs to be a part of the solution for manufacturers,” Ballard said. “It needs to work with everyone in the building industry to make sure we're ready and up to this challenge. As the country emerges from the pandemic, the government signaled it will invest in the green economy.”