is Passive House?
Chances are, you’ve never heard of Passive House before. We certainly hadn’t until we started researching energy efficient building practices. So, I’ll explain what Passive House a little more in depth. There are four main criteria (this is definitely not all though) that must be met in order to be able to considered Passive House.
1. Insulation – There must be adequate insulation in the walls, under the foundation, and ceiling. The amount of insulation actually depends upon the climate that you live in. In our climate here in Atlantic Canada we would be looking at these approximate values: walls – R55, foundation – R30, and ceiling – R100.
2. Air Sealing – Air leakage into (and out of) a house is one of the main contributors to heat loss. In order to minimize this there must be meticulous attention to sealing all spaces which could potentially leak. This means, a lot of tape and sealants!! In order to meet the Passive House standards the house must achieve a blower door test of 0.6 ACH. That means that there would be 0.6 air changes per hour. To put this into perspective the average home built to building code is around 3 ACH and an R2000 home must achieve 1.5 ACH.
3. No Thermal Bridging – Heat can be lost through not only the transfer of air but through the building materials themselves such as concrete and lumber. It is essential to eliminate all of these thermal bridges by ensuring that there is a complete envelope of insulation around the entire house.
4. Energy Usage – A Passive House must meet energy usage requirements as well. As Passive House is a German standard the units are in metric: 15 kWh/m2a. This means that the total energy usage including the heating demands must not exceed 15 kWh per metre square of living space per year.
This list certainly doesn’t incorporate everything there is to know but it will (I hope) give a clearer picture of what the standards are. Lot’s more information can be found at these websites if you’d like to read more.
Another great option which we did a lot was you check out Youtube for videos that explained things. We found a couple of great webinars that were really informative. They are a bit long but you can skip past the first few minutes of introductions.