Ottawa has spent over two years fine-tuning its Canada Green Buildings Strategy, a masterplan to slash greenhouse gas (GHG) emissions from the “built environment” — the 16 million homes and nearly 500,000 buildings where people live and work — to reach net zero in the sector by 2050. It’s a huge task for the country’s third heaviest polluting industry after oil and gas and transportation, once emissions from building heating and cooling systems powered by fossil fuels are factored in. Add “embodied carbon” — the CO2 emitted when manufacturing the materials used in construction, chiefly concrete and steel — and the sector accounts for nearly 30 per cent of Canada’s carbon emissions. “The industry has been slow to change,” green buildings advocate Thomas Mueller told Canada’s National Observer. “Policy and investment decisions taken now will impact new builds and retrofits that will decide Canada’s carbon footprint for decades to come.”