It’s Good To Go Green: Why building “green” is key for the G.R.E.A.T Housing Project.

Updated Dec 20 2023

They give us shelter and sometimes comfort and sometimes even look great. But our buildings are a climate change catastrophe. As the United Nations reports, “CO2 emissions from the operation of buildings have increased to their highest level yet at around 10 GtCO2, or 28% of total global energy-related CO2 emissions.”

Unfortunately the problem with buildings isn’t just the amount of energy buildings use, it also includes the energy that goes into the materials that make up the building. Materials used to create a building have an energy footprint (extraction of raw materials, transportation, manufacturing, etc). This is sometimes called “embodied carbon” or “upfront carbon” or “materials emissions”. No matter what you call these carbon emissions they are huge.

A recent study documents the greenhouse gas emissions from building materials used to construct homes in the Greater Toronto Hamilton Area (GTHA). The results are substantial, revealing roughly 840,000 tonnes of carbon per year, equivalent to the emissions from more than 183,000 automobiles. It can take decades to “pay off” the carbon emissions debt even with highly energy efficient buildings. In other words, building super energy efficient buildings with materials that use a lot of carbon to create, transport, etc is counter productive. For a quick video summary of the report see below:

In addition, many construction materials used in buildings are unhealthy for human and often the planet. As they Healthy Building Network observes “Chemicals that are prohibited from children’s products are ubiquitous in the floors, carpets, artificial turf, playground surfaces, and furniture they interact with just as intimately as they do with their toys, clothing, or personal care products.” The International Living Future Institute (ILFI) has created a “red list” that “represents the ‘worst in class’ materials, chemicals, and elements known to pose serious risks to human health and the greater ecosystem that are prevalent in the building products industry. The ILFI believes that these materials should be phased out of production due to human and/or environmental health and toxicity concerns. “

One promising aspect to this is that often materials that are lower in embodied carbon are also more healthy materials to use.

But how does this connect to affordable housing? The G.R.E.A.T Housing Project recognizes that the crisis of lack of affordable and accessible housing is directly connected to the climate crisis. Due to their high energy use to operate and the high material emissions, the vast majority of housing built in Canada further exacerbates the climate crisis. Essentially each conventional building produced makes the climate crisis worse. As the climate crisis worsens communities are more destabilized through extreme weather events and buildings themselves become less able to withstand such events, further challenging housing stock levels.

The good news is that we can build better right now. The design of G.R.E.A.T Housing’s first building (a sixplex) has already been designed (see this post on general design highlights). Using passive house principles, it is modelled to use about 60% projected less energy use, including 89% reduced heating energy use. It is also designed to have low carbon materials with a focus on healthy materials, avoiding the red list.

But what about the costs? How can we make affordable housing when it costs more to build green? Again some good news here. The initial cost of “going green” isn’t extreme - likely 10% or so. The better news is that each eco affordable unit completed in Canada saves money over similar code homes. The lifetime costs of eco-housing are significantly cheaper than code housing. It makes a tremendous amount of economic sense to build this way.

One study, Monetizing Sustainability The Total Cost of Building Ownership”, showed that “90% of building costs occur after the building is built.” This study compared a code built home to a high energy home and found that costs were 30% lower in the energy built home over the life of the building. Costs included mortgage interest, property taxes,property insurance, energy costs, annual service and maintenance,age-related building renewal. Other studies have echoed these findings, including this one from PEI.

Finally, another good piece of news to finish. When construction is done with lower embodied carbon materials it is generally easier to avoid the dangerous “worst in class” materials. We spend a tremendous amount of time indoors and using materials that are healthy for people and the planet makes sense. 

So at G.R.E.A.T we are going green.

Photo by Greg Rosenke on Unsplash