A new net-zero carbon standard in zero-carbon buildings
According to the University of Oxford, net-zero refers to “a state in which the greenhouse gases going into the atmosphere are balanced by removal out of the atmosphere.”
There are different terms, (carbon neutral, net zero, climate neutral, zero energy, etc.) that describe the ways in which emission sources are accounted for and help to indicate what the source is. In the building sector, the term net-zero is mostly used in conjunction with energy or carbon.
At the core of net zero is the idea of producing as much clean energy as the building consumes, while negating or cancelling out the amount of carbon emitted by implementing methods of absorbing greenhouse gases.
Wendy Macdonald, sustainability consultant with RJC Engineers, has made it her mission to clear up some confusion surrounding these terms and give building owners the tools to reduce greenhouse gas emissions in their buildings by embracing clean energy sources. “Net zero just means a balance of things—and that could be energy, carbon, water, waste, money or even jellybeans,” she tells REMI Network. “If we want to be successful, it’s important to be clear about what we’re trying to achieve.”
A new net-zero carbon standard in buildings
The Canada Green Building Council (CAGBC) recently released the latest version of its Zero Carbon Building (ZCB) – Design Standard, which prioritizes reductions in carbon emissions and embodied carbon. ZCB-Design v3 offers additional thermal energy demand intensity (TEDI) flexibility to incentivize projects to move away from combustion, allowing design teams to optimize their building enclosures and HVAC design for the best possible returns. It also puts a limit on combustion, allowing it only when outdoor air temperature is below -10 C, ensuring a greater transition to electrification of heating. Achieving Zero Carbon Building (ZCB) - Performance Certification means taking responsibility for all carbon emissions associated with building operations, and eliminating climate impacts.
“These updates to the ZCB-Design Standard are informed by two years of market and project feedback, as well as changing market expectations of operational and embodied carbon emissions,” said Thomas Mueller, President, and CEO of CAGBC. “Our research shows that the industry needs flexibility in achieving zero carbon. That’s what our standard provides without compromising our target to eliminate carbon emissions from buildings.”
As the risks of climate change and costs of continued carbon emissions continue to grow, the inherent value of net-zero buildings will be found in Canada’s transition to reach its climate targets. As a main contributor, it will be necessary for the building sector to significantly reduce energy use and carbon emissions by incorporating strategies into the design, construction, and operation of new buildings, as well as by retrofitting existing buildings.