Is Passive Housing the Next Step in Sustainable Construction?

There are a number of ways that developers and builders can earn certification for sustainable construction and energy efficient homes. In Canada, LEED Certification and Energy Star Appliances are quickly becoming the norm in residential construction. However, there’s a new certification on the horizon - Passive Homes - a sustainable construction practice that has already become popular in Europe and is steadily gaining attention in North America. What is a Passive House and why should Canadian builders and developers pay attention? Below we’ve laid out what qualifies as a Passive House and the benefits of this form of energy-efficient housing so you can keep up to date with the latest sustainable strategies.

What is a Passive House?

The term Passive House refers to a voluntary energy-efficient building standard that aims to reduce a structure’s ecological footprint. This green construction strategy creates low-energy buildings that require a fraction of the energy for heating and cooling a given space. Though there are no requirements in regards to which building materials should be used, Passive Houses typically feature superinsulation, advanced window technology and air tightness to prevent heat or cool air leakage, as well as a natural ventilation system. Both the International Passive House Association (iPHA) and Canadian Passive House Institute (CanPHI) report that Passive Houses are approximately 80-90% more energy efficient than standard buildings in Canada and Central Europe.

According to the iPHA, Passive Houses do not require conventional heating and cooling systems, which means that the money saved can be spent on purchasing better windows, improving insulation, and investing in a sophisticated heat recovery ventilation system. This is especially beneficial for houses and buildings in warm or cool climates that usually carry much higher heating or cooling demands. As energy prices continue to climb and non-renewable energy resources diminish, Passive Housing could become an increasingly important option for individuals looking to reduce costs and preserve the environment.

Sustainable.TO's East York Passive House

What are the benefits of building a Passive House?

According to CanPHI, Passive Houses are not only beneficial to the environment, but also contribute to an overall higher quality of life. These versatile structures can be adapted to any climate zone or building type, are almost completely maintenance-free, and have extremely low energy consumption. In addition to being sustainable and versatile, these structures are affordable and comfortable.

One of the many benefits of Passive Houses are their ability to regulate temperature, keeping homes in any climate or geographical region comfortable in all seasons. As their name suggests, Passive Houses are heated ‘passively,’ meaning they make “efficient use of the sun, internal heat sources and heat recovery so that conventional heating systems are rendered unnecessary throughout even the coldest winters.” During the summer months these structures use cooling techniques and efficient shading to keep interior temperatures cool and comfortable.

The high quality insulation and airtight shell keep temperatures level. In Canada, houses looking to achieve Passive House certification must also have “between three and seven times better insulation performance than that provided by the current national and provincial Building Codes.” Excellent insulation coupled with triple-glazed windows and insulated frames helps reduce drafts and heat leakage. These factors also contribute to reducing noise pollution.

Heat loss is reduced by minimizing the total surface area of the building. According to CanPHI, designers use the ‘Shape Factor’ ratio to determine whether a building qualifies for the Passive House designation. This ratio is determined by dividing the building’s surface area by its volume. For example, buildings with ‘sprawling designs’ or features such as heated garages have much higher heat loss and therefore higher Shape Factors.

These structures are also unique in that they regulate the temperature of fresh air before distributing it throughout the building. Instead of spending energy to heat fresh incoming air, this efficient system transfers 75% of the warmth from the used exhaust air to the incoming air supply. This constant supply of fresh air also creates the conditions for better indoor air quality, reducing stuffy-ness while also filtering the air for pollens and dust particles.

A number of countries are beginning to introduce financial support for individuals or companies building Passive Houses. As the demand for energy-efficient construction standards rises, Passive Houses may become one of the most cost-effective means of creating sustainable structures in the near future.

Perhaps the greatest benefit to Passive Housing is its versatility. iPHA explains that Passive Housing Standard does not dictate any specific method of construction and can therefore be built using a variety of materials. This flexibility allows developers and builders, including prefabricated manufacturers, to offer unique Passive House designs. It also means that the qualification can be applied to non-residential buildings and a number of structures in various climates and geographical regions.

Passive Houses in Europe & North America

Europe has been leading Passive House design for the past 20 years. In 2008, the European Union passed a resolution that called on European member states to adopt the Passive House Standard by 2016 for all new construction and renovation projects. Since then, parts of Austria, Belgium, Germany, Luxembourg, Norway, and Spain have adopted the Passive House Standard in their building regulations. Germany alone has constructed over 20,000 Passive Houses, and there are currently 40,000 worldwide. In the United States, the City of San Francisco, Marin County in California, New York City, and the State of Pennsylvania have all taken measures to introduce Passive House standards into the building code.

Canadians are now beginning to embrace the Passive House design and ethos. In 2011, the first certified Passive House residence in Canada was completed in Ottawa and cost just 10% more than a conventionally-built home, while using 90% less energy. Since then, Nova Scotia and British Columbia have also constructed a number of Passive Houses. Here in Toronto, Sustainable.TO, an architecture practice committed to sustainable construction and energy-efficient design, has helped construct Passive Houses in East York and Willowdale.

The Canadian Passive House Institute is also training and connecting people and organizations who want to improve energy efficient construction and learn about the Passive House approach.  The nonprofit has also been training Canadian architects, engineers, builders, and planners on the design and construction process through courses and symposiums. Andre Harrmann, one of the directors at CanPHI, has even created a quick video (below) explaining the concept of Passive Housing in 90 seconds to raise awareness amongst Canadians.

Improving the environment and your quality of life

Julie Torres Moskovitz, author of The Greenest Home, perfectly sums this sustainable practice up, explaining that  “there is lots of concern about climate change and reducing carbon footprint but there is little in the way of a tried-and-true path to make that energy reduction happen. Passive house is it, and your air quality and well-being are improved while reducing your energy consumption so you are not required to sacrifice your quality of life.”

Feature image via CanPHI