Designing, building and living an energy-efficient lifestyle. Architect Shafraaz Kaba is one of the first to attempt to build a net-zero home in Canada.
Shafraaz Kaba, why did you go for an energy-efficient house instead of just a regular family home? I wanted to live in a house that would be simple to operate and demonstrate a straightforward way to build low-energy homes. Low-energy homes are rare in North America. Developers and homebuilders mostly build standard homes that only meet the lowest requirements of the building code.
The house is a first mover in Canada and I wish to be part of paving the way for more energy efficient homes. The house is a long-term building project and we are constantly working to improve its energy efficiency and test new ideas for durability.
What are the advantages of building a passive house? Obviously, the house needs very little heat to keep it warm in winter and remains cool in summer. When the outside temperature drops to minus 20 degrees Celsius, the house maintains a temperature of 16 degrees on a cloudy day without supplemental heating. With passive solar gain, the temperature can even reach 22 degrees inside on a sunny day. A reclaimed brick wall behind the fireplace also helps retain heat and reduces temperature swings indoors. The fireplace is mainly used for comfort and not as a main source of heating thanks to the superinsulation of the house.
How did the energy-efficient components affect the design of the house? The house is very narrow and tall. This reduces the area of the property that is covered and maximizes the area of solar gain so as much energy as possible is collected from the sun. Four layers of ROCKWOOL® products were used to fill the 15inch cavity between the inside and outside studs. The super insulated exterior walls provide the house with very nice, deep windowsills. The sills are a great place for people to sit and enjoy the sweeping view of the North Saskatchewan River Valley, the Edmonton city skyline, and the fantastic big sky over the prairie.
What does a net-zero-ready house mean? A net-zero-ready house has the potential to generate enough power and energy on site to meet its own heating and electricity needs over the course of a year. We are heading for a full, net-zero standard within the next ten years. Besides the 4.8 kW PV system for power, the rest of the house is built with very low-tech materials. Most of the installation was done with the help of friends and family and I chose ROCKWOOL mainly because of its thermal properties and the ease of installation.
What have you learned so far? I learned some valuable lessons building the house and I keep learning. The primary lesson so far has been the value of roof overhangs. On the north side, where the gutter collects water, they should have been placed further from the exterior wall. Also I should have used a peel and stick air/vapour membrane rather than a conventional air barrier and a separate air barrier. This would have made the house even more airtight.
