This new report from Natural Resources Canada and Builders for Climate Action examines embodied carbon in Canadian home building, studying three archetype homes in five Canadian cities at three upper energy efficiency tiers and examining the impacts of using four different material palettes.
The report shows that emissions from home building materials can be significant, with a potential range of 8-20 million tonnes annually. It also shows that relatively simple reductions in embodied carbon via material swapping can bring that total close to zero, or even into net carbon storing territory.
It also shows the scale of material emission reductions to operational reduction can be significant. Homes in regions with relatively clean electrical grids can make material emission reductions that would take hundreds of years to achieve via energy efficiency upgrades.
There’s lots to digest here…
You can download the free report from Builders for Climate Action: https://www.buildersforclimateaction.org/
A recent study noted probably the biggest source of carbon emissions in low-rise construction is the concrete in the foundations Though heretofore overlooked and assumed impractical, there is something of a revival of interest in the elimination of a large amount of the concrete through a number of means. Alternate cements and practice (like pre-placed aggregates concrete to lower past contents) are being reviewed.
It challenges conventional thinking but probably the biggest bang appears to come from eliminating the slab portion of the foundation altogether and substitution of an engineered earthen floor. One project saw a 40% reduction in the embodied carbon of the foundation by the use of a some what conventional earthen floor.
Deep carbon reduction will indeed require challenging convention and assumptions - thinking forward
to solve old problems.