FortisBC pilot demonstrates effectiveness of deep energy retrofits

Key Takeaways:

• FortisBC completed a multi-year Deep Energy Retrofit Pilot across four occupied multi-unit residential buildings, achieving gas use reductions of 50 to 65 percent.
• The whole-building upgrades cut greenhouse gas emissions by up to 60% and generated annual gas utility cost savings ranging from $8,000 to $27,000 per site.
• Participating properties reported significant improvements in indoor air quality, temperature consistency, and building resilience during extreme weather and smoke events.

The Whole Story:

FortisBC has concluded the evaluation phase of its multi-year Deep Energy Retrofit Pilot, demonstrating a practical pathway to modernizing existing multi-unit residential buildings while dramatically lowering energy costs and greenhouse gas emissions. The results from four participating properties show that whole-building upgrades can reduce natural gas consumption by 50 to 65 percent while allowing tenants to remain safely in their homes throughout construction.

The trial evaluated performance data across four representative multi-family sites: The Pendrellis, Manor House, Forte, and Viscount Villa. Each project utilized a tailored combination of building envelope improvements, such as high-performance windows and insulation, paired with high-efficiency mechanical systems and heat recovery technologies. Over a one-year post-construction monitoring period, the completed retrofits delivered annual gas cost savings between $8,000 and $27,000 per building and cut associated greenhouse gas emissions by 50 to 60 percent.

Beyond financial and environmental metrics, the pilot yielded significant improvements in tenant comfort and indoor air quality. Residents at participating properties reported better moisture control, eliminated window condensation, and more consistent indoor temperatures. The upgraded ventilation systems also provided enhanced indoor air filtration during regional outdoor air-quality and wildfire smoke events, proving that deep retrofits can build climate resilience into aging housing stock.

Utility executives emphasized that targeted efficiency retrofits offer a cost-effective strategy for decarbonizing the built environment without requiring immediate, full electrification or costly tenant displacements. “The results from our Deep Energy Retrofit Pilot are incredibly encouraging because they show how existing buildings can be modernized to better serve the people who live in them,” said Doug Slater, Vice President of Indigenous Relations and Regulatory Affairs at FortisBC. “By taking a whole-building approach, these projects significantly lowered gas use, associated emissions and operating costs while helping residents enjoy more comfortable homes and improve building performance. Energy efficiency remains one of the most practical and cost-effective ways to help customers lower their energy use and support provincial climate action goals.”

Municipal and non-profit housing partners highlighted the role of energy retrofits in preserving affordable housing while managing long-term operational budgets. “Working together with FortisBC and other partners on projects like The Pendrellis retrofit provides valuable practical experience in improving existing buildings,” said Vancouver Mayor Ken Sim. “At a time when affordability remains a top concern for Vancouver residents, finding practical ways to reduce energy costs and extend the life of existing affordable housing is more important than ever.”

Brian Jung, Director of Building Asset and Energy Management at the BC Non-Profit Housing Association, added that non-profit societies need sustainable pathways to upgrade aging assets without stretching limited resources. FortisBC is now analyzing the technical data and resident feedback from the trial to determine how these real-world insights can inform a broader, commercial-scale deep energy retrofit program across British Columbia.