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Older homes can significantly reduce their consumption of energy and their emission of carbon, which is a key step towards addressing the energy & environmental challenges facing Canada. This task is easy for new homes, but that's another story.
NRCan data estimate the 15.4 million households in Canada (single detached, attached, apartment, mobile with total floorspace of 24.6 billion ft2) consumed 406 billion kWh of secondary energy in 2022, of which 328 billion kWh (81%) was for the thermal applications of space heating, space cooling & water heating. That means every household consumed 21,307 kWh per year for thermal end-uses or 13 kWh for each square foot of floorspace.
For carbon emissions, the residential sector emitted 56 billion kg in 2022, of which 48 billion kg (87%) was from thermal applications. That means every household emitted 3,148 kg of carbon from thermal end-uses or 2 kg for each square foot of floorspace.
This 3,700 ft2 home near Ottawa was built in 1984 with south-facing orientation and double-wall construction. In 2006, shortly after moving in, we upgraded insulation in the attic and all walls, and implemented basic conservation measures such as converting to LED lights, adding set-back timers & motion sensors, sealing walls against air leakage, installing destratification fans, adding rain barrels, planting dozens of trees, swapping to low-flow toilets, covering ashpalt shingles with an Energy Star metal roof (this increased the efficiency of roof-mounted solar panels which were added later) and upgrading to Energy Star for all appliances & windows (most windows were upgraded to triple-pane with double low-E coating and Krypton gas). The interior was refurbished in compliance with LEED guidelines by recycling building materials and installing FSC-certified teak flooring, among other actions. Our major eco-sin was to import granite from Brazil for the kitchen countertops. We installed a heat recovery ventilator and replaced the propane furnace with a ground source heat pump.
The result was annual energy consumption of 16,300 kWh (4.4 kWh per ft2) and carbon emission of 400 kg (a propane tank was retained for cooking & emergency space heating), well below the 10,000 kg emitted from an average house of this size.
The NetZeroPLUS heat pump produced & delivered the total thermal demand as renewable energy on a dispatchable (no batteries required) basis, and 93% of all grid electricity during the year was consumed in off-peak TOU period ... a major load levelling benefit for distribution utilities, and a rate as low as 2.8c per kWh.
Our renovations boosted the EnerGuide efficiency rating to 90, which was ranked as one of the top energy-efficient retrofits in Canada at that time. An ATIP request showed that 17 homes had been rated higher than ours.
I had spent many years in the geothermal sector, so I designed the horizontal loop system to be oversized and installed it myself. The trench was deeper & longer than required so there was no danger of loop freezing, and the 10 kW backup was never activated in the 14 years we lived there.
Not only does my-green-home show that it IS possible to take personal action that makes a real difference in the climate challenge, but energy expenses declined dramatically, the home is ready for an ice storm or grid blackout, it increases occupant comfort & safety, and it increases equity in future housing stock.
It can get older ... and get better.
As part of our commitment to sustainability, we were the first home in eastern Ontario to mount 10 kW of rooftop solar panels under Ontario's feed-in tariff. The annual output of 9,000 kWh was not counted towards the home's netzeroPLUS status (all output was sold to the provincial grid and could not be used by the home) but the metal roof increased the efficiency of the panels, another demonstration of how a holistic integration can benefit individuals and society.
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To put our investment in context:
In 2005, the average EGH (EnerGuide for Housing) rating for all Canadian homes that had been assessed (a self-selecting universe of energy-conscious homeowners) was 66. Of homes built in the 1980s, the average 'start' rating (before renovations) was 65, and 72 for the 'finish' rating (after all upgrades are complete). To qualify as R-2000, a new house must be EGH 80. NRCan reports that, in 2012, 17 houses in Canada had scored above EGH 90.
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Bill Eggertson has been involved in the renewable energy sector since 1985, managing the Canadian Association for Renewable Energies, Canadian chapter of the International Ground Source Heat Pump Association, Earth Energy Society of Canada, Solar Energy Society of Canada, as well as contract positions with the Canadian Solar Industries Association and Canadian Wind Energy Association, among others. He was senior editor for major renewable energy publications in the UK (RenewableEnergyFocus) and in the US (SolarAccess.com). He was programme manager for the UK government's climate security program in Canada, and was trained by Al Gore under The Climate Reality initiative to explain the implications of anthropogenic emissions of greenhouse gases. His strong commitment to the environment was the reason for his selection as a torchbearer in the 2010 Olympic relay. He now is founder and President of NetZeroPLUS Canada, an association with a mission.
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