The Case for Eco-Friendly Retrofits
Retrofits and renovations are great opportunities to make buildings more eco-friendly. By making use of existing building materials and structures, they are already more eco-friendly than producing, transporting and constructing with new materials. Friends of the Mindemoya Old School will make this building a showcase for eco-friendly retrofits.
Why be environmentally-friendly?
The planet is changing rapidly. Global warming is a fact of life, the planet is heating up faster and faster, and more plants and animals are at risk than at any time in human history. It’s not just some plants and animals — whole networks of ecosystems that support human civilization are at risk.
Since the 1980s, scientists have been warning that greenhouse gases from our activities are causing global warming, which in turn is disrupting climate systems worldwide. Carbon dioxide is the main cause. A gas produced by burning, in the air it traps heat from sunlight, like a greenhouse trapping heat. Here’s a video that explains how it works.
If we continue with “business as usual”, global warming will be devastating. Even now, worldwide there are increasingly severe storms, extreme drought, heat waves, and coastal flooding. These in turn cause more severe fires, crop failure, loss of coral reefs and so on. We have already breached some “tipping points”. For example, higher temperatures are melting permafrost in the high Arctic, releasing a greenhouse gas — methane —that was trapped in the permafrost for tens of thousands of years. Once we cross enough “tipping points”, there is no going back; it’s like a ball that gains speed as it rolls downhill. Here’s a video on tipping points and their effects on us.
It’s getting worse faster. Man-made emissions in the 30 years from 1990 to 2021 were greater than all emissions since 1750, the start of the industrial age.
Focus on buildings
The Canadian Green Building Council says residential, commercial and institutional buildings contribute 17% of Canada’s greenhouse gas emissions, and if you add in materials and construction, that number becomes close to 30%. There is a lot of potential to reduce emissions.
Retrofits are a great start to eco-friendly construction, because most of the building has already been built. The stone has been cut, transported and put in place, the bricks have been fired and assembled, the concrete, wood, glass and other materials are already manufactured and installed. In the building industry, they call this “embodied energy”, and the carbon that was used in building the structure is “embodied carbon”. It’s already in the materials or was emitted into the air long ago.
If the building is in good shape, it makes more sense to retrofit than to demolish it and build something new from scratch. Estimates of the carbon emissions to make and transport one brick to the construction site vary, but 370 grams is an average number given by Construction Canada. Think of the number of bricks in one home! In one Toronto study, carbon emissions from the building materials in homes came to 40 tonnes on average, as reported by the Green Building Advisor.
Other energy-conservation measures are well-known, like insulation, triple-glaze windows, preventing drafts with weather-stripping, and so on.
So what’s the plan for the Mindemoya Old School?
The eco-friendly retrofit has begun — we installed a new roof in 2023. Next steps are attic insulation, heat pumps, and triple-glazed windows. Some interior walls will be partially removed to allow natural light in the main corridor, along with some LED lighting to replace current fixtures, and other features. This is a start.
Eco-friendly roofing has already been installed. The roofing chosen was light grey steel from a local company, TerraStar Building Products in Manitowaning.
Steel lasts twice as long as asphalt tiles, reflects light back into space better, is fire-resistant, and can be recycled at the end of its life. Bright white is the best, in technical terms it has the highest “Solar Reflectance Index”. The Cool Roof Rating Council rates some products for their SRI. The best ratings are in the 90 SRI range, and the lowest are in the 20 SRI range. Material and colour both matter.
Attic insulation is often the first item in retrofits, because hot air rises and insulation keeps the heat in the active areas of the building. R-60 insulation is recommended for new builds in Ontario. In an energy audit, the attic insulation in our building was estimated at R-12, so there is lots of room for improvement.
Heat pumps for heating will replace the old oil boiler, which is at the end of its life. The heat pumps will also replace some air-conditioning systems on the main floor, which were dismantled when the building was closed. Many heat pumps have a seasonal efficiency of 2.5 in this climate. For every kilowatt of electricity used, they produce the equivalent of 2.5 kilowatts in heat.
Triple Glaze Windows are more. efficient than double-glaze. According to Building Advisor, the framing, glazing and spacer are all factors. In general, double-glaze windows have an R-factor of 2, while triple-glaze windows have an R-factor of 3.
We need your help to make this a reality. You can donate, volunteer, and show your support by becoming members of Friends of the Mindemoya Old School. See our home page to check out how.
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