CAGBC releases updated zero carbon standard
The Canada Green Building Council (CAGBC) released the latest version of its Zero Carbon Building – Design Standard last month.
Version three of the ZCB-Design Standard prioritizes reductions in carbon emissions and embodied carbon, and encourages energy-efficient design.
“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.”
The new standard incentivizes projects to move away from combustion. Under the standard, those that eliminate combustion for space heating are no longer required to meet a TEDI target. That means design teams can optimize their building enclosures and HVAC design for the best possible returns.
“This change gives projects the freedom to invest project dollars to achieve the greatest impact at the lowest cost ,” said Mark Hutchinson, Vice President of Green Building Programs and Innovation at CAGBC. “For example, projects might choose to invest in a geo-exchange system and completely electrify, rather than invest in additional envelope efficiency but still use air-source heat pumps and backup natural gas.”
ZCB-Design v3 also puts a limit on combustion, preventing it from being used unless the outdoor air temperature is below -10 C. This change ensures electrification of heating is the new default, only stopping at the point of system limitation. Today, all heat pump applications have options available to -10 C, while some go as low as -30 C. By choosing -10 C, the Standard doesn’t prescribe a solution but makes substantial electrification a requirement.
The standard also introduces a prerequisite for embodied carbon, with the flexibility to choose between absolute embodied carbon targets or relative improvements over a baseline.
The GAGBC says the new limit is a critical next step towards its goal of reducing embodied carbon 40 percent by 2030.
CAGBC’s Embodied Carbon: A Primer for Buildings in Canada report recently calculated that embodied carbon could represent as much as 93 percent of a new building’s cumulative emissions in 2050.
CAGBC says the changes are particularly helpful for smaller buildings and multi-unit residential projects. They were guided by the Zero Carbon Steering Committee, supported by an Embodied Carbon Working Group and CAGBC’s Energy and Engineering Technical Advisory Group.
“These changes were designed with an eye to the simplicity/accessibility of the Standard and a clear focus on driving carbon reductions,” said Doug Webber, Chair of the Zero Carbon Steering Committee and Co-Founder and Principal of Purpose Building. “The intent is to reduce the cost and effort required to achieve the desired outcomes of certification, and to open the Standard to as many projects as possible. I know the changes will remove barriers that some of our clients were facing.”
CAGBC says that for Canada is to meet its climate targets, every building must be a zero-carbon building. Its ZCB standards encourage the transition to zero.
Last month, the council celebrated the 50th building certification under the Zero Carbon Building standards.
Meanwhile, jurisdictions like Vancouver, Toronto and Montreal are implementing aggressive plans to reduce carbon emissions from buildings, while the private sector is complementing those with its own efforts.