Green Real Estate - How Energy Efficient is Your Home

By JAMES RODGERS

The federal government is offering homeowners up to $5,000 to improve the energy efficiency of Canadian Homes. Why is it that these programs designed to reduce energy always provide incentives for us to buy more stuff like furnaces, windows, and energy-saving gizmos?

What about reduction - isn’t our rampant consumerism part of the climate change problem we face? I wonder if the ‘lifecycle’ and ‘stored energy’ footprint of these energy-saving products, and the materials it takes to create them, is being considered in the federal energy efficiency bottom line. Is it worth junking a working 80% mid-efficient gas furnace to replace it with an Energy Star, 92% efficient model?

What about including an incentive for nothing? Perhaps the government could set the bar a little higher than fancy high efficiency gas furnaces by encouraging us to eventually live in homes that don’t require heating or cooling systems at all.

Imagine living in an airtight, mechanically ventilated home with enough insulation in the floor, walls, and attic to not require a furnace, stove or heater. What if this home was so precise and well engineered that the temperature of your body was factored into the heating equation? Such homes and buildings do exist and are found to be warmer in the winter and cooler in the summer than the conventional designs we are used to for around the same price to construct.

Originating in Germany in 1990, Passivhaus (www.passivhaus.org.uk) as they are labeled, are inherently ‘low-tech’, ultra-low energy buildings that heat themselves using sunlight coming through the windows and the people who inhabit them. The 6000+ Passivhaus homes in Europe use simple mechanical ventilation and heat exchangers to insure a healthy, comfortable indoor environment. Some people go so far as to say that the only thing that sets these homes apart from others is that they are built properly.

In isolation air-tightness can be problematic but when balanced with proper ventilation it is integral to an energy efficiency building. Current Canadian building science encourages us to build or retrofit our homes to be as airtight as possible so long as we have mechanical means to insure that fresh air is always available in the necessary quantities.

The accepted goal is to have all of the air in a home exchanged with fresh air every 3 hours. Ideally this would be done utilizing an efficient (80%) heat recovery ventilation (HRV) system that transfers the heat in the outgoing air to the fresh, incoming air.

Most Canadian’s live in older homes in need of air sealing measures. If you were to add all the holes, gaps, and cracks in a home together they would combine to have a total air leakage area as follows:

Pre-World War II Home (to 1945): 53cm (21 in.) diameter hole

Older Home (1946 – 1980): 41 cm (16in.) diameter hole

Modern Home (1981 – present): 35 cm (14 in.) diameter hole

R-2000 Home: 20 cm (8 in.) diameter hole

Looking at the size of these collective holes, one might assume that ventilation and the indoor air quality problems associated with poor ventilation are not an issue for leakier houses. The reality is that without mechanical assistance, factors such as indoor and outdoor temperature and air pressure often do not allow enough ventilation when it is most needed.

If you are weather-stripping doors, windows, and hatches (treat attic and crawl space accesses as exterior doors – insulate and weather-strip) or are undertaking any other air sealing measures in preparation for winter, keep an eye on any ‘side affects’ such as condensation or a ‘stuffy’ feeling to the house. These are often an indication that attention should be paid to the home’s

In acknowledgement of dwindling natural resources and the realities of climate change continuing to manifest, be sure to look into options to diversify your home’s dependency on any single fuel or energy source. Also research options to maximize energy being wasted in the home as heat and how you may be able to utilize the home’s existing equipment and systems in upgrade scenarios. When new equipment is required look for the simplest and most efficient products possible.

James Rodgers is a Certified Home Energy Advisor and Executive Director of the Greener Realty Association of BC.

Submit any ‘green’ and energy-related inquiries to info@clarismedia.com.

For further information visit www.citygreen.ca.