The Canada Green Building Council (CAGBC) introduced the latest version of its Zero Carbon Building – Design Standard, which prioritizes reductions in carbon emissions and embodied carbon.
“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. ”
ZCB-Design v3 offers additional thermal energy demand intensity (TEDI) flexibility to incentivize projects to move away from combustion. Projects that eliminate combustion for space heating are no longer required to meet a TEDI target, says the CAGBC. Now 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. According to the organization, this change ensures electrification of heating is the new default, only stopping at the point of system limitation.
The new limit is a critical next step towards CAGBC’s goal of reducing embodied carbon 40 per cent by 2030. CAGBC’s Embodied Carbon: A Primer for Buildings in Canada calculated that embodied carbon could represent as much as 93 per cent of a new building’s cumulative emissions in 2050.
The CAGBC further states that the changes are particularly helpful for smaller buildings and multi-unit residential projects. The changes 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. 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,” said Doug Webber, Chair of the Zero Carbon Steering Committee and Co-Founder and Principal of Purpose Building. Already, CAGBC is seeing increased interest in this new iteration.