By Paul Dowsett, OAA, FRAIC, LEED AP
Principal Architect — Sustainable. Architecture for a Healthy Planet.
We have only five months to transform the construction industry.
There is no option – or planet – B.
The act of city building needs the literal city builders — the entire construction industry. In response to the climate crisis, our roles as “city builders” must change.
We must cut carbon out of construction – NOW !
Massive amounts of carbon dioxide are emitted into the atmosphere during the construction of a building (embodied carbon) and during the lifetime operation of a building (operational carbon). These massive carbon emissions must stop, we as an industry must change, and here’s why and how.
Why we must change
In 2017, the World Green Building Council (WorldGBC) stated that the global construction industry (emitting 30% of global greenhouse gases (GHG) — similar to China) must operate at “net zero carbon” by 2050 for global warming to remain under 2°C — as per the Paris Agreement.
“Every building on the planet must be ‘net zero carbon’ by 2050”. Every building … whether new and existing.
How can we transform both the operation of existing buildings, and the construction of new buildings, to emit no carbon
How we will change — existing buildings
We can’t reduce the embodied carbon in existing buildings, as it has already been emitted during construction.
But we can retain the building’s existing structure “as-is” or transformed through adaptive reuse. The alternative? Demolish that structure, send its component parts to landfill, and emit more carbon to construct a replacement building.
Additionally? Retrofit that building to be optimally energy-efficient — reducing its ongoing operational carbon.
We know that retrofitting existing buildings is urgent, because they are such huge contributors to a city’s GHG emissions. In Toronto, for example, the 2017 TransformTO study reports that, “In the baseline year