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A Passive House in Victoria, BC by Greg Damant.

Passive House is a standard which certifies buildings who achieve high levels of energy efficiency, and comfort.

The strangest part, perhaps, is not the reasonable price point for which this efficiency and comfort can be gained (in Canada approximately 10% more initial construction cost then standard)… but rather the significant cost SAVINGS over the long term compared to standard building techniques.  The extra capital costs are “heavily outweighed by the net fuel savings (and that’s without taking into account possible dramatic rises in fuel prices in the future)” via CanPHI.

Passive Houses use insulation, airtightness, mitigation of thermal bridges, the sun, internal heat sources, and good heat recovery systems, to make conventional heating systems unnecessary… even in our Canadian winters!  During the spring, summer, and fall, Passive Houses use  passive cooling strategies such as shading to keep comfortably cool.  Because of the high-level of insulation, air-tightness, and minimal thermal bridges, the fluctuation of the indoor temperature is very small.

Passive House offers a realistic option for cost-effective structures that provide high levels of comfort while using very little energy for heating and cooling. In the face of rapidly
increasing energy prices, this makes Passive House an economically attractive option. via

The Passive House Standard does not apply to any particular type of construction: the principle are basic and can be used for every type of building.  There are over 25,000 certified Passive Houses, and many more which follow the Standard but have not been certified.  Most of these are in Central Europe, and only a very small number are in North America.  The reasons for this have to do with our climate, as well as the difficulty of sourcing the well-designed, high-performance parts which are common in central Europe.    As of December 31, 2014,  1,000,000 square meters have been certified by the Standard,  (Press Release here). The smallest Passive House is 11 square meters and the largest is 21,000 square meters in Vienna (see below).

RHW.2 (Vienna, Austria), ARGE Atelier Hayde & Architektur Maurer & Partner (Photo: ARGE Atelier Hayde & Architektur Maurer & Partner)

When we say “high levels of energy efficiency” we mean it: there are space heating and cooling savings of 80% compared with typical buildings, and often levels of insulation more than double standard practice.  The Passive House requirements are:

1. The Space Heating Energy Demand is not to exceed 15 kWh per square meter of net living space (treated floor area) per year or 10 W per square meter peak demand.

2. The Primary Energy Demand, the total energy to be used for all domestic applications (heating, hot water and domestic electricity) must not exceed 120 kWh per square meter of treated floor area per year.

3. In terms of Airtightness, a maximum of 0.6 air changes per hour at 50 Pascals pressure (ACH50), as verified with an onsite pressure test (in both pressurized and depressurized states).

4. Thermal comfort must be met for all living areas during winter as well as in summer, with not more than 10 % of the hours in a given year over 25 °C.

Passive Houses are designed, tested, and certified using a proprietary software known as PHPP.  This software allows architects to specify the insulation and components needed to meet the Passive House Standard, regardless of the climate zone.  Though Passive House began in Central Europe, where lows may be only -15C, many are now being built in most extreme climates: Russia, Finland,  Norway, and Sweden. According to the Canadian Passive House Institute: “Canada’s extreme climate actually makes it a perfect fit for the Passive House approach!”

Sheena Sharp, a principal at Coolearth has undertaken the Passive House training course: if you are interested in something along these lines: get in touch and we can help you realize your passive house dream!