The Province of British Columbia first introduced energy efficiency as a BC Building Code requirement in 2008. Ever since, designers and builders have had the option to use either "prescriptive" or "performance" approaches to comply with the code's efficiency requirements.
To date, the vast majority of builders in British Columbia have pursued the prescriptive approach. Following this approach, buildings must meet specific requirements for insulation, windows, furnaces, water heaters, lighting and other equipment and systems. It focuses on individual elements, rather than ensuring the building functions well as a system. The result can be a building that does not perform as well as intended.
Builders have a second option to comply with the energy-efficiency requirements of the BC Building Code: the performance approach. The BC Energy Step Code offers a specific form of this approach.
The performance approach establishes a desired outcome, and leaves it to the design and building team to decide how to achieve it.
To comply with the BC Energy Step Code, builders must use energy software modelling and on-site testing to demonstrate that both their design and the constructed building meet the requirements of the standard. They may use any materials or construction methods to do so.
This approach echoes that taken by many green-building certification programs, including Natural Resources Canada's Energy Star for New Homes™ and R-2000™ programs, and Passive House Institute (in Darmstadt) certification, as well as the Canadian Home Building Association's Net Zero Home™ and Net Zero Ready Home™ programs.