Home Buyer Energy Checklist for Ontario: What to Check Before You Buy

A home buyer energy checklist for Ontario should cover four things: the age and ownership of the heating, cooling and water heating equipment; the home's insulation and air leakage; the electrical service; and the actual utility bills. Together, these tell you what the home will cost to run and which big-ticket replacements may be coming in your first few years.

Energy costs rarely appear on a listing, but a furnace and air conditioner replaced in the same year can easily cost $10,000–$18,000. Knowing that before you set your offer price is worth an hour of questions.

Home buyer energy checklist: what to ask the seller

Ask your agent to request these before or with your offer, ideally in writing:

1. Twelve months of utility bills, both electricity and natural gas (or oil or propane delivery records). Seasonal swings matter, so a single month is not enough.
2. Age and model of the furnace or boiler, air conditioner or heat pump, and water heater. The rating plate on each unit usually shows the manufacture date or a serial number that encodes it.
3. Whether any equipment is rented, leased or financed, and copies of the agreements. In Ontario, water heater rentals are very common, and furnaces, air conditioners and water treatment systems are sometimes rented too.
4. Service records for the heating system, including any annual maintenance by a licensed gas technician.
5. Past upgrades and permits: insulation, windows, electrical panel work, and any rebate paperwork or EnerGuide evaluation reports.
6. Any oil tank, past or present, above or below ground. Insurers often ask about these, and a buried tank can be expensive to remove.

Caution: Rental and financing agreements can come with long terms and buyout costs, and some have historically been secured by a Notice of Security Interest (NOSI) registered on title. Ontario legislation in 2023–24 restricted NOSIs for consumer goods, with protections taking effect in phases. Have your real estate lawyer check title and confirm how any existing agreements transfer. Verify current rules on ontario.ca.

How old is too old? Typical equipment lifespans

Equipment age is the simplest way to forecast near-term costs. The ranges below are typical, not guarantees; good maintenance extends life and poor installation shortens it.

Equipment	Typical lifespan	Typical replacement cost (2026 estimate)	What to look for
Gas furnace	15–20 years	$5,000–$9,000	Rust, cracked heat exchanger noted by inspector, no service history
Central air conditioner	12–15 years	$5,000–$9,000	Old R-22 refrigerant units (pre-2010) are costly to repair
Ducted cold-climate heat pump	15–20 years	$12,000–$25,000	Model on rebate lists, installer documentation
Tank water heater	10–15 years	Varies; often rented	Rental sticker, leaks, rust at base
Boiler	20–30 years	Varies widely	Leaks, corrosion, oversized older units
Windows	20–40 years	Varies by size and count	Fogged double-glazed units, rot, drafts

If both the furnace and AC are more than 15 years old, budget for replacing both within a few years. That is also the moment to compare a heat pump, which can do both jobs; see our heat pump guide.

What does a home inspection miss on energy?

A standard home inspection looks at condition and safety: is the furnace operating, is the roof leaking, are there obvious electrical hazards. It usually does not measure how efficient the house is.

A home energy assessment by a Registered Energy Advisor (often called an EnerGuide evaluation) includes a blower door test that measures air leakage in ACH50 and produces a rating in gigajoules per year. Older Ontario homes commonly test at 7–15 ACH50; new homes are typically around 2.5–3.5.

In a competitive market you may not have time for an assessment before an offer. You can still check a lot yourself during a viewing:

• Attic: if you can see in, look at insulation depth. Many older homes have only 75–150 mm (3–6 inches), roughly R-12 to R-20. R-50 to R-60 is a common retrofit target.
• Vermiculite: pebbly, grey-brown loose fill in the attic may contain asbestos and should be tested before any work.
• Basement: are the walls insulated? Is the rim joist (where the floor framing meets the foundation) sealed and insulated?
• Windows: single-glazed or fogged sealed units, and drafts around frames.
• Comfort clues: cold rooms, rooms over garages, very hot upper floors, ice dams or heavy icicles at the eaves in winter.

After you take possession, an assessment can rank upgrades properly. Learn more in our home energy assessment guide.

Check the electrical service

Many older Ontario homes have 60 A or 100 A service. That is often enough today, but adding a heat pump, Level 2 EV charger and electric range can push a home toward 200 A. Service upgrades typically cost roughly $2,500–$6,000 or more including utility work (an estimate), although load management devices can sometimes avoid one.

Look at the main breaker label in the panel, and ask the inspector to flag knob-and-tube wiring or older aluminium branch wiring, which some insurers restrict. Our panel upgrade guide explains the options.

How to read the seller's utility bills

Compare annual totals with typical Ontario figures:

• Electricity (no electric heat): roughly 7,000–9,000 kWh a year.
• All-electric or heat-pump homes: often 12,000–20,000 kWh or more.
• Natural gas (detached home, gas heat and water heater): roughly 2,000–2,600 m³ a year.

Adjust for size, location and household. A home in Sudbury will use more heat than the same home in Windsor, and a family of five uses more hot water than a couple. Much higher usage than typical, without an obvious reason, points to air leakage, poor insulation or inefficient equipment. Our home energy checkup can help you think through likely causes.

Your first year: low-regret moves after moving in

Once you own the home:

• Choose your electricity price plan deliberately rather than keeping the default.
• Change the furnace filter and book a heating tune-up if there is no recent service record.
• Test smoke and carbon monoxide alarms. Ontario requires CO alarms in homes with fuel-burning appliances or an attached garage.
• Read any rental agreement in full, and decide whether to keep, buy out or replace.
• Check current rebates before replacing anything. Owner-occupied homes are generally eligible for the Home Renovation Savings Program, but heat pump rebates need pre-approval before installation.

Frequently asked questions

Can I ask the seller to replace an old furnace?

You can negotiate, but many buyers prefer a price reduction or credit instead. That lets you choose the replacement yourself, including the option of a heat pump, rather than accepting the cheapest unit a seller installs in a hurry.

Should I avoid a house with a rented water heater?

Not necessarily. Rentals are common in Ontario. What matters is the monthly fee, remaining term and buyout cost. Read our water heater rental guide before closing so the agreement holds no surprises.

Is a home energy assessment worth it for a buyer?

If you plan major renovations, yes. It shows where heat is lost and is required for some rebate routes. Many buyers book one shortly after taking possession, before starting renovations.

What is a reasonable energy budget for my first home?

Use the seller's bills as a starting point, then adjust for your household. As a rough guide, a typical detached Ontario home with gas heat might pay roughly $250–$450 a month across both utilities in mid-winter and noticeably less in summer (an estimate; the range is wide).