Heating or Eating: The Origin of the EnviroCentre Retrofit Accelerator at Carver Place

With funding support from Natural Resources Canada, EnviroCentre has completed deep energy retrofit work on 63 townhouses with Multifaith Housing Initiative.

Social housing is essential housing.

In Eastern Ontario, there are over 28,000 units of social housing that would directly benefit from deep energy retrofits.

28,000 households who would live in greater comfort, experience less sickness and live in homes that are more resilient and efficient.

The EnviroCentre Retrofit Accelerator was created to help address the needs of social housing providers and the challenges to scaling deep energy retrofit work. EnviroCentre has doing energy audits and home retrofits in the national capital region for over 25 years. It’s become an imperative to increase the scale of this work to meet the immense challenges of the affordability and climate crisis.

What is the EnviroCentre Retrofit Accelerator?

The retrofit accelerator is a program designed to retrofit an entire community at one time and to address the energy and future-proofing needs of those communities at scale. Our aim for each project is to reduce energy use by 50% and greenhouse gas emissions by 80%.

The initial steps include exploratory stages of analysis and testing undertaken with test units of housing in a potential community project. EnviroCentre believes in a holistic approach to the retrofit work in any building. Using industry tools such as energy audits, blower door tests and energy data analysis, EnviroCentre builds a baseline data set and understanding of the energy and air leakage controls. Work plan design centers on recommendations that align with maintenance and repairs the buildings current needs.

What is the EnviroCentre Retrofit Accelerator at Carver Place?

In 2023, EnviroCentre was approached by a social housing provider in Ottawa to help address a simple need: 63 townhouses needed new furnaces. The original furnaces had reached their end of life.

For some, an energy retrofit can be as simple as replacing old appliances with mechanical systems that are Energy Star® certified. It could be replacing an old gas furnace with a new high-efficiency gas furnace. Or replacing it with a heat pump. Or replacing old windows and doors.

For Melanie Johnston, EnviroCentre’s director of Energy Programs, this was an opportunity to build on  an idea she had: why do deep energy retrofits one house at a time, if you can do a whole neighbourhood at once. Through established relationships with 1Click and O’Reilly Brothers, EnviroCentre wanted to take advantage of the economies of scale for the equipment, materials and labour. Forget about what the cost is for a single air-source heat pump. What price can we get for 63 of them?

And the EnviroCentre Retrofit Accelerator came to life. Instead of just replacing old furnaces, EnviroCentre developed a replicable and scalable program to retrofit an entire neighbourhood community. This work plan centred around being able for people to continue living in their homes while the work was carried out.

What retrofit work was done?

Work at the Multifaith Housing Initiative, Carver Place community, was designed to be carried out in phases. This design was intentional. One of the main concerns for any housing provider is where are the people supposed to live while the work happens. The phased approach was developed to mitigate the potential disruptions to people’s daily lives. Along with project funders and our retrofit contractors, 1Click and O’Reilly Brothers, we were able to source the equipment and materials at scale to substantially drive down the costs for the project.

Below is a comprehensive list of the work and new equipment:

• Cold-climate heat pump
• heat pump water heater
• high-efficiency gas furnaces
• energy recovery ventilator (ERV)
• Basement rim joist insulation
• attic air sealing
• spray foam insulation blown cellulose

Next steps

As part of the Carver Place Energy Retrofit Accelerator project, EnviroCentre engaged with McGill University’s ReCONstruct project and Carleton University’s CABER program.

We wanted to use this project as a test case to see how the real-world lived experience and energy usage would compare to computer modeling for townhome retrofits.

The reasons for this are not only social, but to better understand the tenant’s experience of living in a home before a deep energy retrofit and after the work is complete. McGill University is working to collect data related to the non-energy benefits which include comfort, experience of heating and cooling, and data related to health outcomes. Carleton’s CABER program is tracking three specific variables: temperature, relative humidity and CO2 levels. In addition to this, they can track specific voltage and energy use by individual pieces of equipment to answer the question with real world data: how much energy does a heat pump use for example.

This data collection started in summer 2025 and will continue through the summer of 2026.

How can we help you?

From single buildings to whole communities — we’re helping social housing providers scale what works.

Whether you manage a few dozen homes or an entire housing portfolio, our Retrofit Accelerator can help you identify opportunities, build cost-effective plans, and deliver results that last.

Let’s build a retrofit strategy that improves comfort, reduces costs, and helps your organization get the greatest impact from every dollar invested.