Walls: they hold up our houses; hide stuff like wiring, plumbing and insulation that make life indoors kind of nice; and keep out noise, cold weather and nosy neighbours. We tend to think of them as solid and silent, but if these walls could talk, they might tell you how much heat and air can leak through poor insulation and around doors and windows.

The fact is, the walls of most buildings standing today weren’t built for energy efficiency. Prior to the adoption of the National Energy Code for Buildings in the late 1990s, standards for energy efficiency, like airtightness and thermal transmission, weren’t written into local building codes. So should we tear down thousands of inefficient old houses and buildings and rebuild to the new standards? Of course not: imagine the waste! The disruption! The loss of homes and familiar streetscapes and stories of the people who live there.

There’s got to be a better way…

The good news is we can upgrade insulation, replace windows and doors and add air sealing to make the building envelope of existing homes and buildings better, more airtight and energy efficient for years to come. Heating, hot water and ventilation systems can be upgraded to high efficiency so they use less energy and reduce greenhouse gas emissions.

This is what’s known as a deep energy retrofit. By targeting improvements in building envelope and HVAC systems, the goal is to reduce energy use and greenhouse gas emissions by 50 per cent or more.

And now we’re conducting a pilot called the Deep Energy Retrofit Pilot Program involving four multi-unit residential buildings and 20 single family homes across B.C. to show how this whole-building approach can help reduce energy use and greenhouse gas emissions. Best of all, deep energy retrofits are designed to be minimally disruptive, so people can still live in their homes during the renovation process.

Meet some of the participants in the Deep Energy Retrofit Pilot:

What does a deep energy retrofit mean for single family homes?

Each homeowner in our pilot has a unique story to tell about their home and why they’re participating.

Jonathan Baylis, Deep Energy Retrofit Pilot Program participant.

Jonathan Baylis' 1940s Tudor-style home.

Rebecca and Dan Poelman, Deep Energy Retrofit Pilot Program participants.

Rebecca and Dan Poelman's home was built in the 1990s.

Renee Simard, Deep Energy Retrofit Pilot Program participant

Renee Simard's home in the Kootenays was originally built in the 1920s

Jonathan Baylis has lived in the 1940s-era home where he raised a family for 30 years and is keenly interested in energy efficiency. Proactively calling his local municipality about grants and programs to help make his house more efficient over the years eventually led to learning about our pilot program.

Dan and Rebecca Poelman are raising a young family in a 1990s-era home in the Lower Mainland that, despite its relative modernity, leaks heat around the doors and windows and has a 30-year-old furnace that’s getting expensive to run. They’d been shopping around for replacements when Dan happened to see an email from FortisBC about deep energy retrofits and decided to apply.

And Renee Simard bought her house in the Kootenays a few years ago. Originally built in about 1920, the house has had a variety of additions and renovations done over the years. Even with some double-pane windows, she says it still feels like “there’s a breeze going through the house” in winter. But as a seasoned renovator and with a master’s degree in sustainability, she was excited to find out about the pilot. She’s looking forward to not only updating her house but also the lessened environmental impact and energy bills.

I feel very fortunate that I’ll be getting the deep energy retrofit. So that includes upgraded insulation in the attic, new windows, doors and new mechanics in the basement, including a heat pump.

Renee Simard, residential Deep Energy Retrofit Pilot Program participant

What upgrades make up a deep energy retrofit?

Each of the 20 homes in the pilot received an energy assessment from our implementation contractors for residential homes in this project. Their energy audits and calculations of projected energy and emissions savings help determine which houses will benefit the most from which upgrades.

Installation of these upgrades began in the summer of 2023. For most houses, upgrades will include:

• new doors and windows
• added insulation
• improved airtightness and air sealing measures
• new high-efficiency furnace or boiler

Some houses will also have heat recovery ventilation, exterior cladding and/or a new hybrid heating system (electric heat pump and gas furnace combination) installed.

It’s all about reducing the amount of energy a building requires through upgrading the envelope. Then you can reduce the equipment size or ‘right size’ the equipment while maintaining customer comfort and reducing energy.

Jim Kobialko, C&EM manager, innovative tech & projects, FortisBC

How are we retrofitting existing multi-unit residential buildings for high efficiency?

The four multi-unit residential buildings in our pilot are homes to many people. Two are non-profit housing and two are apartment rental buildings, and all projects require a high level of coordination between the participants, their project partners and our implementation contractors (RDH Building Science and SES Consulting) to help minimize disruption to residents during the process.

For example, the Pendrellis building in downtown Vancouver is a concrete highrise built in 1973 by the non-profit Pendrellis Society and provides housing to about 90 seniors. During the energy assessment process, a thermal imaging drone scan showed massive heat loss through the exterior concrete and single-pane windows. Deep energy retrofits planned for Pendrellis will include:

• new triple-pane windows
• new cladding to insulate the exterior
• a new roof
• new gas absorption heat pumps to replace the old gas boiler for heating and hot water
• heat recovery ventilation installed in suites
• upgraded hallway ventilation system

TJ Roberts, project liaison for Pendrellis

An energy assessment report estimates that these upgrades can reduce energy use by about 65 per cent—a huge savings to the non-profit society, as well as reducing its greenhouse gas emissions. TJ Roberts of Duality Projects, who liaises between the Pendrellis Society, project stakeholders and Pendrellis residents, is enthusiastic about how the project will make the building more comfortable for the seniors who live there, from reduced noise due to triple-pane windows to better ventilation and more even indoor temperatures. If the bulky portable air conditioners and space heaters currently being used by residents are no longer needed, it should also help free precious square footage in the small studio suites.

Implementation of the upgrades for Pendrellis and the other multi-unit residential buildings in the pilot is expected to begin in fall and winter 2023.

What else will these walls tell us? 

After all the upgrades are installed, the implementation contractors will conduct post-installation assessments to quantify the actual energy usage and airtightness improvements in each home and building. Our pilot program will also gather information on participants’ experiences with the process and the differences they see and feel in their homes and buildings.

What we learn from the Deep Energy Retrofit Pilot Program will help determine if we can offer a full-scale program to our customers in the future. We’ll be updating this blog as the pilot progresses, so be sure to check back to see what else these walls can tell us about deep energy retrofits. Be sure to also follow @fortisbc on social media for more videos and updates from our participants.