The City of Ottawa has embarked on a strategy to encourage voluntary greenhouse gas (GHG) reduction retrofits of existing industrial, commercial and institutional (ICI) and large multi-unit residential buildings.
The blueprint, called the Better Buildings Strategy, will focus on how to achieve zero GHG emissions by 2050 by reducing heating and cooling demand and switching from natural gas to zero carbon fuel sources.
It is part of the city’s ambitious Energy Evolution Strategy which sets out targets for retrofitting buildings and achieving thermal and electrical savings. The targets require a retrofit rate per year of almost five per cent of buildings. To date, retrofit rates in Ottawa have been less than one per cent per year.
City council approved the plan because existing buildings are the single biggest source of GHG emissions in Ottawa. Statistics in 2019 show ICI buildings contributed 22 per cent of Ottawa’s GHG emissions.
“It’s a fairly steep reduction curve that they’ve committed to in the Energy Evolution Strategy,” says Janice Ashworth, project manager, environmental programs, in Ottawa’s infrastructure and economic development department. “That’s where the Better Buildings Strategy comes in. It tries to answer the question of, ‘How are we going to accomplish this fairly momentous task of retrofitting effectively all buildings in Ottawa?’ ”
The success of the strategy depends on mass retrofit uptake by all building owners. The city plans to play a catalyst role by educating, financing and removing barriers to deep energy retrofits of all private ICI buildings.
“What we found when we did the modelling is that the most effective way to meet those emissions reductions, basically make every building net-zero, is by first reducing the demand and that can be done through envelope improvements — improving the exterior with insulation and with air-sealing to keep the heat in.
“The other strategy, especially for commercial buildings, is a lot can be done with controls and automations.”
For example, explains Ashworth, turning off lights, heating and ventilation in rooms that are not being used can reduce emissions and result in cost savings.
“Having automated systems can really help in reducing demand in commercial buildings where the occupancy can really vary quite a bit.”
After reducing demand, “fuel-switching” is another important element, in other words using electricity instead of fossil fuels to heat buildings because they are a big emitter of GHGs, says Ashworth.
She notes Ottawa has a slight advantage when it comes to cooling because the city doesn’t have as many hot days as other cities and cooling systems use electricity which is a less carbon-intensive form of energy.
A key step in driving adoption of the strategy will be an energy benchmarking program that will involve collecting and measuring the performance of buildings to show where improvements can be made. A virtual audit of a building’s monthly utility bills will be done and compared to data from a typical building of comparable size to see if the structure is ahead or behind the curve.
“You can get a fair bit of information, so we’re offering these virtual audits for all participants in this benchmarking and auditing program,” says Ashworth. “We’d like them to submit their monthly utility data through a fairly easy online portal and then we’ll give them a virtual audit.”
Thermal scans of a building envelope will also be used to determine where heat might be leaking from a building through windows or insulation and identify where improvements could boost energy efficiency.
“It’s kind of a newer approach but we’re looking to pilot it in Ottawa to see how it works. Ottawa is a pretty cold climate so we’re going to need to do more when it comes to insulation and improving our building envelope than they might have to do in Toronto, for example.”
Ottawa conducted audits of its city-owned buildings and found the exercise to be very effective, so the thinking is that the offer could be extended to private buildings and see if they benefit as well, says Ashworth.
Studies have shown that energy-efficient buildings have 10 per cent higher occupancy rates, 10 per cent higher premiums on rents, and 25 per cent higher sales prices when compared to less efficient buildings.
The city also intends to rollout marketing, education and training components, help building owners with access to low-cost loans and long-term capital for retrofits, look into requiring buildings to undergo energy audits and meet emissions performance standards and, as the capital of Canada, work with other municipalities to adjust land transfer or property taxes to reflect carbon emissions of buildings.
Retrofitted buildings benefit the community in many ways beyond the carbon emissions reductions, a staff report says.
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