If you’re shopping for a resale home, you can know almost all the financial responsibilities you’ll face for a given house before you buy it. Almost all, but not quite. At least not yet.

You can know mortgage payments and property taxes down to the penny, but the wild card is still energy costs. For that you’ll need to wait for your name to be on the deed and utility bills to arrive in the mail. It’s a problem because as energy costs rise, some people could face monthly heating and electricity bills higher than their mortgage payments. That’s a pretty big unknown, but it doesn’t have to stay this way.

Manufacturers are required to publish independently verified information about the energy consumption of, say, a new fridge, car or dehumidifier, among other things. But energy consumption is a black hole as far as prospective resale home buyers are concerned, at least until politicians follow through and do the right thing. And that right thing involves an efficiency tool built by Canadians.

Canada is in the final testing stages of developing something called the EnerGuide Rating System for Houses (ERS). It’s a new way to measure how much energy a home really uses, how much it produces from sustainable sources such as solar or wind, and how overall consumption of the house compares with other homes in the area. ERS is a great advance for both resale home buyers and home sellers, but it’s got a big hurdle to cross — mandatory implementation.

ERS lets people in the home market see exactly how the energy consumption of various properties compare with each other. And the difference from one house to the next can be huge. For example, a good home might use about 60 gigajoules of total energy annually. A leaky, cold money pit could easily use three times this amount. Some super-efficient homes today even use no net energy overall, producing all they need right on site. Mandatory ERS ratings applied to all homes is the only way to know true energy consumption before you buy.

ERS figures are much better than asking someone with a vested interest to show you old utility bills because EnerGuide numbers are generated by independent third parties. No one has an incentive to gild any lilies, or “forget” to include all the electric, gas or oil bills in the tally.

Home sellers benefit from ERS analysis, too. They can let their efforts at energy-efficient renovations show through in a way that the marketplace can reward. Everything you do to keep the heat in and drafts out shows up in a lower ERS score that’s directly comparable to houses nearby.

As good as ERS is technically, an energy rating system is only as good as the extent to which it’s used. That’s why implementing it is key and governments are beginning to step in.

Ontario is the first province to announce plans for making home energy labelling mandatory for resale houses. According to the schedule, this is supposed to happen in 2019. I say “supposed to” because change as big as this might take some public support to make it real.

Dozens of interested parties and individuals from across the country are part of the Home Energy Transparency Coalition (HomeEnergyTransparency.org), and it’s a worthy model for everyone across Canada. Grassroots support and organizations are working together because this plan is so important.

Energy dependency is the sleeping tiger in Canadian society. In a country as cold and as big as ours, our economy and even our very lives depend on a steady supply of energy. And if that’s not incentive enough to measure home energy performance across the board and learn to use energy wisely, I really don’t know what is.