BC Energy Step Code Airtightness Testing for Part 3 Buildings

Project Visioning and Sustainable Design Charrette
October 26, 2020
Deeper Thinking: Building Energy Audits for Carbon Reduction
November 2, 2020

Whole building airtightness testing is a regulatory requirement for residential and non-residential new construction projects in British Columbia under the BC Energy Step Code. With an increased focus on airtight buildings, verification of the performance of the air barrier system is required via whole building airtightness testing to demonstrate reduced air leakage rates through the building enclosure. Improved airtightness impacts the overall energy efficiency of the building by reducing heating and cooling loads while helping to provide a comfortable indoor environment.


Watch this video for a virtual experience of a demonstration airtightness test of a multi-unit residential building at the University of British Columbia. The video summarizes

  • the best practice steps and processes that make up a successful airtightness test in Part 3 new residential buildings, including site preparation, testing procedures, trouble shooting, results and reporting procedures.
  • BC Energy Step Code Part 3 airtightness testing requirements and recommendations on how to plan and incorporate airtightness testing in a project’s design and construction phases.

Project Background

The UBC Mundell House is a new 123,000 sq ft rental residential project with 135 units for faculty and staff comprising two linked 6-storey buildings. While the building was designed to meet an energy target through UBC’s policy, it was not designed and constructed to meet a specific BC Energy Step Code performance target. Airtightness testing was optional at that time, however the Project Team decided to conduct an airtightness test in July 2020 to understand the building’s performance and to serve as an example for future UBC Properties Trust projects which will be required to meet the Energy Step Code.


Video Project Team

  • BC Hydro – New Construction Program
  • Building and Safety Standards Branch, Office of Housing and Construction Standards, Ministry of Municipal Affairs and Housing
  • UBC Campus & Community Planning
  • Crew Production
  • ZEBx

Mundell House Project Team

  • UBC Properties Trust
  • ZGF Architects Inc
  • Ventana Construction
  • Aqua-Coast Engineering Ltd