Understanding the BC Energy Step Code

With the BC Building Code update fast approaching, you may want to explore what new amendments look like in relation to increasing energy efficiency requirements. The BC Energy Step code will be implemented province-wide first and require professionals in the residential construction industry to become familiar with a whole new set of targets and processes. Our experienced team at Shoreline Building Performance can answer your questions and provide the necessary resources to help you meet these new standards.

What is the BC Step Code?

The BC Energy Step Code is a performance-based approach to meeting energy efficiency requirements for buildings. The code was first introduced in 2017 and provides a tiered path forward toward Net Zero Energy Ready buildings for all new construction by 2032.

The first two steps of the BC Energy Step Code have been voluntary so far. The next code cycle, expected to be released later this month, will make Step 3 of the BC Energy Step Code the preferred compliance path going forward. Although a prescriptive backstop has been included in draft versions of the building code update to allow compliance in regions without access to an energy advisor, much stricter minimum values must be met to comply with this route. The performance path has been noted to be much more cost effective in markets with access to an Energy Advisor. 

To learn more information on the BC Step Code  continue reading here.

Breaking Down the Metrics

The metrics measured by the BC Energy Step Code measures for Part 9 and Part 3 buildings, can be broken down into 3 major categories: airtightness, equipment and systems, and the building enclosure. 

We’ll begin by looking at airtightness, as it is the simplest of the 3 metrics to explain. Airtightness simply measures the amount of uncontrolled leakage between the interior of the home and the exterior environment and is measured in air changes per hour (ACH). One air change equates to the entire heated volume of air in the house being replaced by outside air. This can be measured using a blower door to pressurize or depressurize the building to a pressure, typically 50 pascals (Pa) in a residential application. To achieve Step 3 of the BC Energy Step Code, builders must achieve an airtightness value of 2.5 ACH for single-family detached homes. Working with an energy advisor to conduct a pre-drywall blower door testing and blower door directed air sealing can be a valuable exercise in learning the common leakage points, as well as diagnosing and correcting any major deficiencies early in the project to ensure targets are met. Once the home is complete, an as-built blower door test is required to comply with the BC Energy Step Code, and the final values will be input into the as-built energy model. While it is not the explicit goal of including airtightness targets in the code, an airtight home with proper ventilation contributes to good occupant health. By keeping harmful airborne pollutants outside the home and preventing many of the issues related to the movement of moisture laden air through the building envelope, good indoor air quality is a by-product of a well-designed high-performance home.

To learn more about the step code measures, read more here.