The City of Vancouver is a world leader in addressing embodied carbon in the built environment, having set a target of reducing embodied carbon from new buildings by 40 percent by 2030. But in order to make reductions, there must first be a benchmark understanding of embodied carbon emissions in today’s new homes. This study examines 13 typical new homes using as-built
plans to assess the carbon footprint attributable to the structure, enclosure and partitions of these homes. Using the BEAM estimator tool, each of the 13 homes was modeled, creating a valuable data set.
● Net emissions for whole homes ranged from a low of 10.5 to a high of 140.1 tonnes ofc arbon dioxide equivalent (CO2e), with an average of 43 t CO2e.
● Emissions intensity ranged from a low of 138 to a high of 357 kilograms of CO2e per square meter of heated floor area, with an average of 193 kg CO2e/m2.
● Emissions intensity from the sample homes in Vancouver align closely with those from a similar study in the Toronto region, which had an average emissions intensity of 191 kgCO2e/m2.
● The authors recommend that the City of Vancouver use 200 kg CO2e/m2 of heated floor area as the benchmark for embodied carbon in new Part 9 homes. To meet the target of a 40 percent reduction in embodied carbon, new homes will need to achieve an
emissions intensity of 120 kg CO2e/m2 by 2030.
● The three most impactful material categories are concrete (36 percent of total emissions across all homes), insulation (21 percent) and interior surfaces (10 percent).
● A home with relatively high emissions intensity of 227 could be reduced to 127 kg CO2e/m2 by swapping just eight materials for available and competitive alternatives, coming close to meeting the 2030 reduction requirements.
● A home with relatively low emissions intensity of 138 kg CO2e/m2 could use the same eight material swaps to achieve 44 kg CO2e/m2, far surpassing the 2030 target.
● Material swaps for the best possible materials could bring homes in the study to net zero embodied carbon and even into net carbon storage.
● There appeared to be no direct correlation between embodied carbon and energy efficiency, a finding that corresponds with similar studies. It is possible to meet the highest levels of energy efficiency with a building made from low embodied carbon materials.
● The City of Vancouver should consider the metrics it will use to measure embodied carbon for incentives and regulation. This study uses emissions intensity by heated floor area, but the results are different if a metric of emissions intensity per bedroom is used.