So what defines a passive house? Is it just relaxed, chill, and down to follow the leader? Well not quite:
“It is a building standard, considered the most rigorous voluntary energy-based standard in the design and construction industry today, resulting in buildings that consume up to 90 percent less heating and cooling energy than conventional buildings. Applicable to almost any building type or design, the Passive House (Passivhaus) high performance building standard is internationally recognized, science-based and proven.” - Passive House Canada
The name actually comes from the german “Passivhaus”, passive in the sense that the building envelope does the majority of the work to maintain a comfortable temperature, allowing for smaller, simpler mechanical systems. The name also applies to any building, not just a residential home, and to new and existing buildings.
So why go passive? There’s a myriad of benefits but the top ones are:
Comfort - a thick layer of insulation and eliminating thermal bridges makes sure there are no hot or cold spots. This maintains consistent temperatures from floor to ceiling.
A Healthy Environment - a heat recovery ventilation system brings fresh air in year round. A Passive House certified system will deliver it silently to every occupied room without drafts while exhausting stale air where moisture or odours exist.
A Quiet Setting - Thick insulation, triple pane windows, and careful sealing create an acoustic barrier that blocks out a lot of exterior noise.
A well functioning building with simple operation - The need for complex and expensive technology and controls is greatly reduced. It’s about careful design, simple durable systems, and quality construction.
An Affordable Home - maintenance and energy costs are greatly reduced resulting in lower operating costs over traditional buildings.
Market Value - Quality energy efficient buildings hold there value and command a higher price point. For more on this check out our post “Greener Home, Greener Wallet”.
Peace of Mind - There’s a good feeling you get knowing a building is truly a sustainable and quality building. Knowing it was built to the highest standards makes buyers, and tenants feel better.
Now those are all well and good, but what’s actually measured?
Primarily it comes down to energy consumption and air leakage. Targets for heating and cooling are up to 90 percent less than average buildings in Canada, and total energy consumption is often 50 percent less than average. In addition homes have to meet specific ventilation and comfort criteria.
Space Heating Energy Demand - 15 kilowatt hours per square meter of Treated Floor Area demand per year or 10 Watts per square meter peak load.
Space Cooling Energy Demand - matches the heat demand/load requirements but with a small additional allowance for dehumidification.
Primary Energy - total energy used in operation of the home is limited to a specified number of kilowatt hours per square meter of Treated Floor Area per year, varying with the level of certification and use of renewable energy.
Airtight Enclosure - allowable limit of 0.6 air changes per hour at 50 Pascals pressure (ACH50) that is verified with an onsite blower door test (pressurized and depressurized)
Noise Levels - maximum noise levels in sleeping and living areas is must be less that 25 dBA
In summary, concentrating on getting a few key factors right allows for a simple, quality construction, resulting in an extremely comfortable and energy efficient home. Hopefully the next time you see the Passive House certification you’ll be armed with what that really means for the home, your comfort, and the environmental impact it has.
Would you like to see more articles exploring the different building standards? Email firstname.lastname@example.org and let us know!