Passive house

Passive House is an approach to designing homes so they’ll consume much less energy to operate than typical code-built homes. There are five main ways to achieve this goal:

1 - Add plenty of insulation to the envelope (floor, walls and roof) and reduce/eliminate thermal bridges (other parts of the envelope, like wood studs, window frames and service conduits, that conduct heat to the outside)

2 - Attain high levels of airtightness by carefully sealing gaps and holes during construction

3 - Install high-performance windows and doors

4 - Incorporate excellent ventilation and heat recovery

5 - Orient windows to take advantage of solar heat gain

According to Passive House Canada:

• Passive House buildings consume up to 90% less heating and cooling energy than conventional buildings

• In a Passive House building the primary goal is to achieve a superbly well-insulated and tightly sealed building envelope, then introduce fresh air via a very high-efficiency heat recovery ventilation system

• The benefits of employing Passive House standards include fine-tuned control over indoor air quality and temperature with simple-to-use and durable systems, making them extremely quiet and comfortable throughout the changing seasons. 

• The reductions in operating costs quickly make up any additional costs associated with construction, and the reduced carbon emissions provide priceless peace of mind.

When preparing to build a Passive House, the design and construction team must be integrated with a certified Passive House designer during planning, to ensure the home is designed to achieve its performance goals and to be built cost-effectively. Energy modeling helps guide the design of the home’s form, or massing, and its assemblies, like floors, walls and roof. Extra investment is made in the insulation, windows and doors, and labour to carefully craft the home’s air seal. These improvements mean that a much smaller and less expensive mechanical system is sufficient, offsetting some of the initial costs. As a result, because the heating costs are so low, the total cost to build and operate a Passive House will soon be less than a house built to the basic building code. As an added bonus, Passive Houses are more consistently comfortable throughout the year, their indoor air quality is cleaner and healthier, and exterior noise pollution is virtually eliminated.

Canada’s climate plan, building codes at various levels of government, and municipal climate strategies are in place to effect change in the building industry. In order to build, companies first must model how much energy the house will use, and must find ways to reduce emissions in order to avoid penalties. Passive House is a common-sense way to achieve these goals from an operational perspective, and some municipalities in Metro Vancouver even offer density bonuses and square footage and height relaxations allowing for the thicker wall and roof assemblies.

Resources:

• Passive House Institute

• City of Vancouver guide to Building a Passive House and Passive Design Toolkit