CaGBC Zero Carbon Building (version 2)



The CaGBC Zero Carbon Building (ZCB) Standard is a framework for designing and retrofitting buildings to achieve net-zero carbon in Canada. The standard takes a holistic approach on reducing carbon emissions in buildings including upfront (embodied) carbon emissions from building materials and construction and operational carbon emissions through reducing overall energy consumption, decreasing peak energy demand, and off-setting grid supplied power with on-site renewable energy generation.

The ZCB Standard is divided into two types: design and performance. The ZCB-design standard is applicable for new construction or major renovations, while the ZBC-performance standard is for annual certification of existing buildings. Certification for the ZCB-design standard is awarded based on the final design and how it reduces carbon emissions, such as achieving modeled operational carbon balance and reporting embodied carbon emissions through life-cycle analysis. Similarly, certification for the ZCB-performance standard is awarded based on one year of operating data, including achieving a zero carbon balance and offsetting embodied carbon emissions.

In order to achieve ZCB-design certification, all projects must conduct a life-cycle analysis (LCA) that includes:

  • upfront carbon (life-cycle stages A1-5),
  • use stage embodied carbon (life-cycle stages B1-5),
  • end of life carbon (life-cycle stage C1-4)
  • beyond the life-cycle carbon (life-cycle stage D) may be reported as supplemental information

The LCA must assume a building service life of 60 years and should include new materials only and must account for all building envelope and structural components, including:

  • footings and foundations,
  • complete structural wall assemblies (from cladding to interior finishes, including basements),
  • structural floors and ceilings (not including finishes),
  • Roof assemblies and stairs
  • Parking structures (excluding excavation and other site development, partitions, building services (electrical, mechanical, fire detection systems, elevators etc.) and surface parking)

The LCA must be initiated at the schematic design phase and be summarized in an Embodied Carbon report that includes a list of recommendations that were considered or implemented to reduce embodied carbon of the project for the final design.

Buildings seeking ZCB-performance certification can meet embodied carbon requirements by offsetting the embodied carbon emissions from design and construction of the building. Projects may choose to offset equal amounts of embodied carbon over as many as five years. Beyond the life-cycle carbon (life-cycle stage D) is not included in the LCA and does not need to be offset.

1) Canadian Green Building Council (2021). Zero Carbon Building Standard Version

Back to top of page