Natural Resources Canada (NRCan) delivers the EnerGuide Rating System (ERS). Nearly all energy conservation and energy efficiency programs and incentives that the government of Canada and many provincial rebate programs use the ERS to benchmark existing energy use and potential savings that can come from improving your home's energy efficiency.
If your house was evaluated in the past, you can check for the Energuide rating label, likely on or around the electrical panel.
The label includes:
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Your EnerGuide rating: the modelled energy consumption of your home measured in gigajoules per year. The lower the rating, the less energy you consume.
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A typical new house reference: the EnerGuide rating your home would have if it had been built to current building code. Your current home’s rating may be more or less efficient than a brand new home.
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Breakdown of the rated annual energy consumption: A pie-chart breakdown of the major energy uses within the house and an initial overview of where you can lower home energy costs.
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Greenhouse gas emissions: the estimated GHGs emitted annually as a result of using energy in your home.
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The EnerGuide Rating System changed from a 0-100 scale to Gigajoules per year back in 2016. There are a lot of houses out there with old style Energuide labels on them. Some people still refer to the zero to one hundred scale in conversation, because it was an easy shorthand.
Under the old system a rating of 100 represents a house that is airtight, well insulated, sufficiently ventilated and requires no purchased energy, while an old leaky house with no insulation would come in somewhere under 50.
Why did it change? A few reasons.
First, as we've all been brought up through schools that graded us on a percentage basis, we're conditioned to think that 75 percent is a decent grade, and therefore, we don't really need to work harder to get to an 80, which was the equivalent of an R2000 house under the old system.
Hard to Scale Up Energy Efficiency
Second, moving past 80 was really, really hard, as each point was worth something along the lines of thirty-five hundred to five thousand gigajoules of energy usage over the course of a year. The higher up the scale, the tougher it got to level up.
It was easy to get a house from say 65 to 75 with relatively inexpensive energy efficiency improvements like air sealing, insulation blown into empty walls, boosting attic insulation, swapping out old heating equipment for higher efficiency new units. But then, that pesky building science and unintended consequences kick in when the house gets tighter and better insulated and then you need to add more complex and expensive energy upgrades like controlled mechanical ventilation and make up air for combustion appliances and, and…
We’re talking mainly about retrofits, but new construction was not much different in terms of the measures required to use less energy and move up the scale. Getting to 100 was nearly impossible, and very, very expensive.
Third, what does it mean to improve from a 65 to a 75 under this point system? It’s not as simple as oh, that’s a 10 percent reduction in energy use! A one-point improvement on the old rating scale could represent a 3 to a 5 percent reduction in energy consumption.
Fourth, once we got on the path to Net Zero Energy in housing, it was confusing to have a Net Zero House with an Energuide label rating of 100 for a house that essentially had zero energy costs.
More Gigajoules, More Energy Consumption
Now, it’s much more user friendly: the better the home's energy performance, the lower the figure on the Energuide label. The closer to zero the gigajoule per year measurement is, the more efficient the house is. The higher the gigajoule per year number, the less energy efficient the home is. Homes that produce as much energy as they use have a rating of zero.
Why gigajoules? A gigajoule is a unit of measurement for energy that doesn’t care about the fuel source – electricity, natural gas, oil, propane or wood. BTUs, kilowatt hours and other measurements are converted, and now we’re comparing apples to apples, because the energy use rating is fuel neutral.
The gigajoule per year system also gives a better understanding of the impact of energy conservation measures and promotes better energy performance. If your EnerGuide rating goes down from 100 GJ/year to 90 GJ/year – that’s a 10% improvement. In the Energuide rating system, everyone's household appliances are rated the same - it's the home energy consumption for space heating and cooling plus water heating that is compared.
What didn’t change is the fact that an Energuide label doesn’t reflect your actual energy use as shown on your utility bill. That's because the rating is based on standardized usage regimes for thermostats, hot water usage, and lighting as well as the loads for major household appliances.
This means the rating on the Energuide label reflects how much energy is required to heat and cool the house under standard conditions, as opposed to how an individual household might use energy.
There’s also an Energy Intensity Unit that is also on the label, showing gigajoules per meter squared. This allows homebuyers to compare the relative energy costs of different houses they are considering. Home energy efficiency can be the deciding factor between similar options when buying a home.
The Energuide label is the result of a home energy audit, carried out by a registered energy advisor. It gets attached to your electrical panel (or close by) at the end of the assessment process. Energy advisors can be hired to improve energy efficiency in a planned new home, or to conserve energy in an existing home.
