BC Step Code
The Step Code is a new BC provincial standard that provides an incremental and consistent approach to achieve energy efficient construction. Ultimately the goal is to have all new buildings be net zero energy by 2032. They divided it into 5 steps, with step code 5 being a net zero building. Our latest project achieved step code 4, which is basically a building that is at least 40% more efficient than an average home built to today’s standard. Here is a brief overview of how we achieved that level of efficiency:
We wrap the house with a synthetic sheathing membrane, taped at the seams, and tied into the window sealing for a continuous air barrier. We then wrap the entire house with 2″ of ridgid mineral wool insulation. Blower door testing before drywall confirmed an air tightness of 1.0 Air Changes per Hour at 50 Pa. We installed triple glazed windows with 2 low e coatings for maximum energy efficiency.
We combined an air source heat pump and an HRV to heat, cool and provide fresh air to the home. The heat pump was a fully ducted system with a SEER rating of around 20, and an HSPF of around 11. I’ll describe different heat pump options and ratings in a future blog. We also had a wood burning fireplace on the second floor for backup.