Canada’s Zero Carbon Standard Requires Embodied Carbon Offsets

The Canada Green Building Council (CaGBC) was the first to launch a national standard for carbon neutrality in buildings. Now version 2 has been released with changes that include multiple compliance paths for energy efficiency, a requirement to offset fugitive refrigerant emissions and embodied carbon, and a higher bar for carbon offsets. The standard still does not require projects to account for carbon emitted by occupants’ transportation to and from the building.

This version continues to offer both a design standard (a one-time certification for new buildings) and a performance standard (an annual certification for existing buildings), but it incorporates lessons learned from twenty completed zero-carbon building projects, according to CaGBC. In the design standard, flexibility has been added with three possible compliance paths for energy efficiency. Teams must provide an energy model demonstrating that the project is expected to meet one of the following:

•  a stringent benchmark for thermal energy use intensity (TEDI) (20–30 kWh/m²/year),
•  a less stringent TEDI benchmark and exceed a site use intensity threshold, determined by project type, or
•  a less stringent TEDI and achieve a zero-carbon balance by purchasing a renewable energy system (as opposed to green power products or carbon offsets).

The performance standard has become more stringent in that embodied carbon now must be offset prior to performance certification. Teams must use life-cycle assessment software to estimate embodied carbon for all new envelope and structural elements (existing structures are exempted). Estimated embodied carbon then must be offset within five years.

Concerned that refrigerants used in heat-pump equipment will leak into the atmosphere or be disposed of improperly, the standard also requires that teams report the quantity and global warming potential of any refrigerant that is used for HVAC. If there are any refrigerant leaks in the first year of performance, the project must offset the equivalent amount of carbon emissions. Purchased offsets must be high quality and ensure additionality (that the project or activity offsetting greenhouse gas emissions would not have happened otherwise). The standard lists five programs to choose from.

In total, updates to the standard are intended to “provide the rigor needed to ensure zero emissions—and the flexibility to encourage widespread adoption of zero carbon buildings,” according to the CaGBC website.

For more information:

ZCB Standard
cagbc.org