This text is part of the special Environment section
Caulking your windows, renovating instead of demolishing, reducing the ambient temperature by a few degrees in winter, relying on innovative technology: there are many small gestures that have a big impact on the energy footprint of our buildings.
On Parc Avenue in Montreal, the old store had been practically abandoned. In 2006, the general manager of Écohabitation, Emmanuel Cosgrove, and his family recycled its materials and renovated the building to transform it into a triplex. Examples of green renovations like this are all over the province, says the green housing consultant. But before embarking on major work, small gestures can have a big impact on the energy footprint of our homes, assures the latter.
In the province, it is estimated that almost a third of the energy consumed is associated with our buildings. Of this portion, Hydro-Québec calculates that a household’s energy consumption is distributed as follows: 54% goes to heating and air conditioning, 20% to water heating, 18% to appliances and electronics, and 5 to 10% for lighting.
“What costs us the most is to heat the water and the air,” summarizes Emmanuel Cosgrove. We can turn off the lights, in the background, [pour une véritable économie d’énergie], we must use less hot water and keep the heat inside by caulking the little cracks that we have everywhere around our windows in our homes and by stopping up our chimneys. If you take the trouble to do this, the savings, energy efficiency and payback period are immediate. »
“We know that with insulation work, we can reduce our energy consumption by half on the building envelope, adds Stéphanie Lopez, sustainable real estate advisor at Vivre en Ville. The main challenge for cities today is to renovate the housing stock. We are working on thermal insulation, waterproofing, high-performance glazing, etc. »
Renovate and reduce consumption
What if we started from scratch to build a more sustainable building? As tempting as it is, the idea turns out to be bad. The demolition indeed generates large piles of scrap ending in the dump, while the construction of a new building involves hidden energy costs, argues Stéphanie Lopez. “And there is all the hidden energy of the building, linked to construction, the extraction of minerals, the manufacture of materials, which are emitters of greenhouse gases (GHG)”, she explains.
The main challenge for cities today is to renovate the housing stock
To reduce the environmental footprint of our buildings, Stéphanie Lopez also recommends reducing at source. “Energy in Europe is much more expensive, so people are much more careful,” observes the French-born consultant. I’m a little helpless in Quebec, because consumers don’t know what they’re really consuming. For example, few people know that in the middle of winter, Hydro-Québec uses fossil fuels because it does not produce enough hydroelectric energy. »
Instead of heating the house to 23-24°C in winter, she suggests putting on a little wool and reducing the ambient temperature by a few degrees. Good thermoregulation, with windows located on opposite facades that optimize natural ventilation during the summer, will also limit the use of air conditioning.
For Denis Leclerc, President of Ecotech, technology can also help us reduce our consumption. “There are all kinds of technologies that can detect that there is someone in the office and activate the lighting and air conditioning. These occupancy sensors are going to have an impact on energy consumption,” he points out, adding that they allow energy use to be adjusted according to factors such as human presence, time of day. of the day or the degree of sunshine.
It forces us to change our ways of looking at design, says the man who also advocates for the adoption of mechanisms to reuse energy in our buildings.
“With gray water, for example, when you take a shower, all the hot water goes down a drain,” he points out. However, we are seeing more and more devices that capture the heat from this water and use it to heat the cold water in water heaters. »