We went to Ottawa for Family Day weekend to visit my husband’s family. A few weeks before this, I received a press notice that an Ottawa house had become the first Passive House certified in Canada. “Say,” I thought, “wouldn’t it be great if I could arrange for a tour of the house while I was in Ottawa?” So I did.
If you’re not familiar with the Passive House movement, houses are designed and built so that they only use 15 kwh/m2 of energy for heating and cooling and 120 kwh of electricity per month for lighting, appliances and other household uses. To give you an idea of what this means, the typical new home built in Ontario today uses about 10 times the amount of energy consumed by a Passive House certified building. If you’d like to know more about the Passive House movement in Canada, you can read about it here.
Chris Stratka of Vert Design was intent on building a super-insulated home when he bought the property in the New Edinburgh neighbourhood of Ottawa. However, when he took the design to a Passive House consultant he was told it probably wouldn’t qualify because the building materials and systems available in Canada that he had specified were seen by the consultant as inferior to those available in Europe. Although Chris was disappointed, he decided that he’d build the “best” house possible and leave it at that. Specifically, Chris is aiming for a Platinum LEED for Homes rating, with a particular emphasis on the Energy and Atmosphere section of the certification.
Chris decided that the best way to achieve his home’s performance targets was to use a modular home builder, and located one just outside Ottawa who would build to his insulation specifications. As I’ve written about before, modular home building has several environmental advantages such as the materials being protected from the elements (moisture, heat, cold, etc.), less waste in production, and less disruption to the local neighbourhood because the final product is put up so much faster. Chris’ home was assembled on site in three weeks. Yes, there was still the need for electricians, HVAC installers etc., but the major construction vehicles were on the street for a short period of time and there was never a dumpster on site.
Once the walls were assembled, insulation was added to the ceiling, caulking and sealing was done, Chris called in green building specialist, Ross Elliott from Homesol Building Solutions, a building performance consulting company that provides third-party inspection, testing and verification services. Ross performed the blower door test to identify any leaks that might have escaped the caulking and sealing. Chris said that if you’re going for energy efficiency in a new or renovated home, it’s essential to bring in the energy auditor a few times while the house is under construction. It’s much easier to fix leaks and holes in a partially built home than once the drywall is up and everything is already in place, and it will save you money in the long-run through lower energy bills. It was after the initial test that Chris and Ross believed that they just might be able to qualify for Passive House certification after all.
There are two other aspects about the house that were of primary importance to Chris:
1. He built it using only North American supplied materials in order to demonstrate that we North Americans have the resources and the technology to build super-insulated homes. All the major building materials, hot water heaters, geothermal heating/cooling, and windows are manufactured in Canada and the US.
2. Testing for air leaks at several stages of building was essential to achieving the home’s air tightness.
In order to build a Passive House certified residence, there are several elements in addition to air-tightness that are essential to take into consideration:
Orientation: Part of the Passive House formula is the ability to take advantage of the free heat a house can receive in the winter by orienting windows to absorb the light. In this case the house if perfectly situated, facing due south, and backs onto conservation land next to the river. It means he’ll never have to worry about another building going up that would eventually block his sunlight and heat source. The canopy in place protects the room from the heat in the summer when the sun is high in the sky. The shading system that is currently being installed protects the rooms from the heat of the low winter sun. In this building the issue is not getting enough heat – it is getting too much!
Windows: All windows are “tilt and turn” windows provided byInline Fiberglass, a window manufacturer based in Toronto, ON. They are triple-glazed, Low emissivity, argon gas filled, and the fiberglass frames themselves are insulated. The day I visited it was -15, but when I put my hand to the window pane, the glass was warm. When I do the same thing on my own home’s windows, the glass is always chilly; in fact, it’s just plain cold anywhere around any window in our house.
A nifty feature of the windows is the “tilt and turn” aspect. They tilt open at the top to let air flow in or out, or can be opened completely as a door on side hinges. This is a great feature to quickly cool down a room in the summer time, if the hot air has risen to the third floor.
Heating and Cooling System: In hindsight, Chris says, the geothermal heating and cooling system he had installed wasn’t necessary. However, when first designing the place, and being told that it would never pass Passive House certification, he figured he’d use the least intrusive HVAC system he knew of — geothermal. His particular system is made by Maritime Georthermal from New Brunswick. In future passive house designs, he would use baseboard heating in each room as Passive House homes are designed so that traditional heating methods such as central furnaces, aren’t necessary. He’s also added a Heat Recovery Ventilator (HRV), from Airia Brands from London, ON. When I asked him why he hadn’t chosen an Energy Recovery Ventilator (ERV), he replied that ERVs are more suited to humid climates where moisture is present year round.
For a complete breakdown of the specifications of the wall composition and HVAC, hotwater and windows used, please see Chris’ PDF document on his website.
Other “eco features.” Passive House certification’s focus is on energy use for heating, cooling and plug load. It does not look at other factors such as indoor air quality, water use, or minimizing the use of building materials. Chris referred to LEED criteria for these areas. Some of the more eco-friendly features of his house are:
- Green Roof garden. Essentially his house takes up the entire plot of land, with only a small patch of property out back. Since he would like to grow some of his own food, he has designed the roof so that it can hold a substantial garden with herbs, tomatoes, beans and other vine plants, and maybe some crooked carrots (the depth of the soil will be about a foot). The green roof will also add further insulation to the home.
- Rainwater recycling. There is a space built into the second floor that is awaiting rain barrels which will capture run-off from the eavestroughs and will be stored inside the home to feed toilets with water. The point of putting the rain barrels on the second floor is that the water is fed to the toilets through the use of gravity. That way they are unaffected if the electricity goes off.
- Energy Star Appliances. All appliances, including washer/dryer, are Energy Star rated. The cooktop by Kenmore, uses induction heating, which is also quicker than gas.
- No gas line to the house. Chris says that there are two reasons he relies on electricity for heating and cooling, cooking and hotwater: the first is that gas doesn’t fully combust and is not indoor air quality friendly, and secondly, to become dependent on gas means that you can never convert your home to 100% renewable electricity. Chris has plans for solar panels on the roof.
For more information on this project, visit VertDesign.ca
For more information on Passive House certification, visit the Passive House Institute US.