Verified October 25, 2026 against Tarion, Save on Energy, the City of Toronto, the Electrical Safety Authority, Health Canada, MPAC billing guidance from the Town of Milton and the InterNACHI life expectancy chart.
Short answer: Over 10 years, an older GTA house usually costs more to keep up than a newer one, because more of its big systems (roof, furnace, air conditioner, water heater, sometimes wiring, pipes and insulation) reach the end of their life while you own it. A newer house front-loads its cost into a higher purchase price instead. In our worked example, the older house needs about $26,800 more in upkeep over 10 years, while a $50,000 lower price saves about $20,500 in mortgage interest and land transfer tax over the same period. The gap is close enough that the answer depends on the actual ages of the systems in the house you are looking at, not the year it was built.
What “older” and “newer” mean here
There is no official cut-off. For this guide, an older home is a house built before about 1990 that still has some original or mid-life systems, such as much of the postwar housing across Toronto, Mississauga and Brampton. A newer home is one built in roughly the last 10 to 15 years, including brand new houses from a builder.
The year of construction matters less than you might think. A 1965 bungalow with a new roof, a five-year-old furnace and updated wiring can be cheaper to own over the next decade than a 2012 house whose original furnace, air conditioner and water heater are all due at once. The useful question is always: how old is each major component, and what will it cost to replace while I own the house?
If you are still deciding between buying new from a builder and buying resale, our guide to new home vs resale home covers HST rebates, Tarion, closing delays and builder adjustments. This guide picks up after the purchase and looks at what the next 10 years cost.
How long the big systems last
The table below uses the International Association of Certified Home Inspectors (InterNACHI) estimated life expectancy chart, which home inspectors widely use as a rough guide. InterNACHI says the figures are guidelines only, not guarantees. Actual life depends on installation quality, maintenance and, in the GTA, freeze-thaw winters and humid summers.
| Component | Estimated life | What it means over 10 years |
|---|---|---|
| Asphalt shingle roof, 3-tab | 20 years | Any 3-tab roof older than 10 years is likely due while you own the house |
| Asphalt shingle roof, architectural | 30 years | Usually fine for a decade if under 20 years old |
| Furnace | 15 to 25 years | A furnace over about 10 years old may need replacing within 10 years |
| Central air conditioner | 7 to 15 years | Even a five-year-old unit may need replacing before year 10 |
| Heat pump | 10 to 15 years | Similar to air conditioning |
| Conventional water heater | 6 to 12 years | Expect at least one replacement in almost any house |
| Vinyl or fibreglass windows | 20 to 40 years | Original 1980s and 1990s vinyl windows may be near the end |
| Sump pump | 7 years | Likely one replacement per decade where there is one |
| Asphalt driveway | 15 to 20 years | Older driveways may need repaving |
| Caulking, interior and exterior | 5 to 10 years | Every house needs this redone at least once |
| Exterior paint | 7 to 10 years | Every house with painted trim or siding |
| Electrical service panel | 60 years | Original panels in 1960s houses may be at the end of their life |
Short-life items like the water heater and air conditioner wear out on a similar schedule in any house. The real difference is the long-life items: roof, furnace, windows, panel, pipes and insulation.
Costs that show up more in older homes
Roof and furnace replacements
These are the two most common big bills. Our 2026 roof replacement cost guide puts an asphalt shingle roof on a detached Toronto house at about $8,800 to $16,500. Heating options and current rebates are in our guide to home heating systems in Ontario. Ask the seller for receipts or permits showing when each was last replaced. Without them, ask the home inspector to estimate the age.
Wiring and insurance
The Electrical Safety Authority (ESA) says knob and tube wiring was installed in homes from the early 1900s to the 1940s. ESA says it is safe if properly maintained by a Licensed Electrical Contractor, and Ontario’s electrical code is not retroactive, so existing wiring does not have to be removed. But ESA also notes that many insurers see it as higher risk and some may require you to replace it before they will provide coverage. An article in Canadian Underwriter says most insurers treat knob and tube, aluminum wiring and 60-amp service as high-risk. Get an insurance quote before you firm up an offer, not after.
Lead water service pipes
The City of Toronto says homes built before the mid-1950s should strongly consider replacing a lead water service pipe. The City owns the pipe from the watermain to the property line; the owner is responsible for the private section from the property line into the house. Under the Priority Lead Water Service Replacement Program, the City replaces its section on a priority basis, aiming for 12 weeks after approval, once the owner commits to replacing the private side. A licensed plumber can check the pipe, or you can ask 311 to check City records, which can take up to 30 business days. The City does not publish a cost for the private side, so get a plumber’s quote.
Insulation, air leaks and windows
Older houses were built to older energy rules and many have had only partial upgrades. That shows up in heating and cooling bills, drafts and ice dams. The best way to put a number on it is to ask the seller for 12 months of gas and hydro bills and compare them with a newer house of a similar size. A home energy assessment, which Save on Energy’s program rebates by $600 as part of a bundle, shows exactly where the heat goes.
Health Canada says vermiculite insulation made before 1990 may contain asbestos. Its advice is not to disturb it. If the insulation is sealed off from the living space, the risk is very small, but it can add cost to an attic or renovation project because it has to be handled properly.
Basement water
Many older GTA houses were built with weeping tiles connected to the sanitary sewer and no backwater valve. Toronto’s Basement Flooding Protection Subsidy Program covers up to 80% of invoiced costs, up to $1,600 per backwater valve (up to two), $2,250 for a sump pump, $300 for a battery backup, $400 for severing and capping the weeping tile and $500 for a plumbing assessment.
Costs that show up in newer homes
Newer houses are not free to own. They tend to have these costs instead:
- A higher purchase price. You pay for new systems up front, and that money is borrowed at mortgage rates. It also raises your land transfer tax.
- Short-life systems still wear out. Water heaters, air conditioners, sump pumps and caulking follow the same schedule in a new house. A house built 8 to 10 years ago can face several of these bills at once.
- A catch-up property tax bill for brand new homes. The Town of Milton explains that MPAC sends a Property Assessment Change Notice within three years of moving into a new home, and the resulting supplementary bill can go back to the closing date and cover up to two past years. Each bill is due in one instalment, so set money aside. Property tax rates are the same for old and new houses in each city; only the assessed value differs. Compare rates in our GTA property tax rates guide.
- Finishing costs on a brand new house. Window coverings, fencing, landscaping, a deck and an unfinished basement are often not included. These are your own choices, so we have not put a number on them, but budget for them.
- Warranty paperwork. A new freehold home comes with Tarion coverage, which is valuable but has deadlines. You have to report problems on time to keep coverage.
What Tarion covers, and what it does not
| Period | Main items covered |
|---|---|
| 1 year | Workmanlike construction and freedom from material defects, Ontario Building Code compliance, fitness for habitation, unauthorized substitutions, and installation defects in builder-supplied appliances |
| 2 years | Water penetration through the basement or foundation walls and the building envelope, exterior cladding problems, defects in electrical, plumbing and heating delivery and distribution systems, and Building Code violations affecting health and safety |
| 7 years | Major structural defects in load-bearing parts of the house |
The seven-year warranty excludes heating and cooling equipment such as furnaces and air conditioners. Tarion’s maximum coverage for a freehold home is $400,000 for agreements of purchase and sale signed on or after July 1, 2023, and $300,000 before that. The warranty starts on the closing date, so a house bought resale at age five still has only the remaining structural coverage, and the one-year and two-year coverage has already ended.
A 10-year worked example
To show how the numbers can play out, here are two detached houses in Toronto. Every replacement cost below is an assumption for illustration, except the roof, which uses the midpoint of our 2026 roof cost guide range ($8,800 to $16,500, midpoint $12,650). Replace them with quotes for the house you are considering.
- Older house: built in the 1970s, roof about 18 years old (3-tab), furnace about 20 years old, air conditioner about 14 years old, owned water heater about 10 years old, thin attic insulation, no backwater valve.
- Newer house: built about 5 years ago, architectural shingles, furnace, air conditioner and water heater all about 5 years old.
| Item | Older house | Newer house | Why |
|---|---|---|---|
| Roof replacement | $12,650 | $0 | 3-tab roof at 18 years vs 20-year life; architectural roof at 5 years vs 30 |
| Furnace replacement (assumed $6,500) | $6,500 | $0 | 20 years old vs 15 to 25 year life; newer furnace reaches only 15 |
| Air conditioner replacement (assumed $5,000) | $5,000 | $5,000 | Both reach the end of a 7 to 15 year life within 10 years |
| Water heater replacement (assumed $2,000) | $2,000 | $2,000 | Both pass 6 to 12 years within the decade |
| Attic insulation top-up (assumed $3,000) | $3,000 | $0 | Older house below current levels |
| Backwater valve (assumed $2,500) | $2,500 | $0 | Newer house assumed to have one |
| Caulking and exterior touch-ups (assumed $1,000) | $1,000 | $1,000 | 5 to 10 year life for caulking |
| One-time costs | $32,650 | $8,000 | |
| Less rebates and subsidies | $2,850 | $0 | $1,250 attic insulation rebate (Save on Energy) plus $1,600 backwater valve subsidy (Toronto, 80% of $2,500 is $2,000, capped at $1,600) |
| Routine upkeep, 10 years (assumed $1,500 vs $1,000 a year) | $15,000 | $10,000 | Servicing, small repairs, gutters, filters |
| 10-year total | $44,800 | $18,000 | Difference: $26,800, about $2,680 a year or $223 a month |
The arithmetic: older house $32,650 minus $2,850 plus $15,000 equals $44,800. Newer house $8,000 plus $10,000 equals $18,000.
Now add the price difference
Suppose the newer house costs $50,000 more. That is an assumed gap: there is no published TRREB or MPAC figure for how much house age changes price. If you borrow the extra $50,000 at an assumed 4.5% fixed rate over 25 years (Canadian mortgages compound semi-annually):
- The extra payment is about $277 a month.
- Over 10 years you pay about $33,208, of which about $19,484 is interest. About $13,724 goes to principal, which you keep as equity, and about $36,276 is still owed.
- Ontario land transfer tax on the extra $50,000 is $1,000 (2% in the $400,000 to $2,000,000 band). In Toronto, the municipal tax adds another $1,000.
So in this example, the older house saves about $20,484 in interest and provincial land transfer tax ($21,484 in Toronto) but costs about $26,800 more to keep up. The newer house comes out roughly $5,300 to $6,300 ahead over 10 years. Change one assumption, such as a roof that was replaced five years ago or a $100,000 price gap, and the result flips.
Two things the example leaves out. First, at the end of 10 years the older house has a new roof, furnace and insulation, while the newer house’s roof and furnace are 15 years old and closer to their own replacement. Second, energy and insurance costs, which can favour the newer house, are not included. Use real bills and real quotes for those.
This is general information, not financial, tax or mortgage advice. The costs above are assumptions for illustration. Get quotes from licensed contractors and talk to your mortgage professional before you decide.
10-year cost calculator
Enter your own numbers. The calculator compares the 10-year interest and land transfer tax on the price difference with the extra 10-year upkeep of the older house. It assumes both prices fall in Ontario’s 2% land transfer tax band ($400,000 to $2,000,000) and does not adjust for inflation.
Rebates and subsidies that cut older home costs
Several programs are aimed at exactly the upgrades older houses need. Amounts below are from the program pages as of October 2026. Each has its own terms, and funding can change, so confirm before you start work.
| Program | Upgrade | Amount |
|---|---|---|
| Home Renovation Savings (Save on Energy with Enbridge Gas) | Attic insulation, single upgrade | $1,250 |
| Home Renovation Savings | Insulation as part of a bundle with an energy assessment | Up to $7,700 |
| Home Renovation Savings | Home energy assessment (bundle path) | $600 |
| Home Renovation Savings | ENERGY STAR windows and doors (bundle path) | $100 per rough opening |
| Home Renovation Savings | Air sealing (bundle path) | Up to $250 |
| Home Renovation Savings | Cold climate air source heat pump | Up to $7,500 |
| Home Renovation Savings | Heat pump water heater (bundle path) | $500 |
| Home Renovation Savings | Smart thermostat | $100 |
| City of Toronto Basement Flooding Protection Subsidy | Backwater valve, sump pump, battery backup, weeping tile capping, plumbing assessment | 80% of invoiced cost, up to $6,650 per property |
The bundle path means starting with a home energy assessment and then completing two or more upgrades. Toronto's subsidy requires a licensed contractor, original invoices and an application within two years of installation. Mississauga, Brampton and other GTA cities run their own programs; check your city's site.
What to check before you buy
For any house
- Ask for the age of the roof, furnace, air conditioner and water heater, with receipts or permits.
- Ask whether the water heater, furnace or air conditioner is rented. A rental contract usually transfers to you.
- Ask for 12 months of gas, hydro and water bills.
- Get a home inspection. Our inspection checklist lists what to test.
- Get an insurance quote before you firm up.
For an older house
- Wiring type and panel size. If the inspector finds knob and tube or aluminum wiring, consider an assessment by a Licensed Electrical Contractor.
- The water service pipe material. In Toronto, ask 311 or a plumber if the house was built before the mid-1950s.
- Attic insulation type and depth, and whether there is vermiculite.
- Backwater valve, sump pump and how the weeping tiles drain.
- Permits for past renovations. See our guide to unpermitted renovations.
For a newer house
- Whether a supplementary property tax bill has been issued yet. If not, budget for it.
- What Tarion coverage remains and whether any claims were filed. A house past its second anniversary has only structural coverage left.
- The age of the short-life systems. A house built 8 to 10 years ago may be due for an air conditioner and water heater soon.
Comparing an older house with a newer one? We can pull recent sales so you can see the real price gap on the streets you are looking at. Talk to us about buying, or get a free home evaluation if you are thinking of selling.
Common questions
Is an older home more expensive to own than a newer one?
Usually yes over a 10-year period, because more of its long-life systems, such as the roof, furnace, windows and wiring, are likely to need replacing while you own it. A lower purchase price can offset some or all of that. Compare the ages of each system rather than the year the house was built.
How long do roofs and furnaces last in the GTA?
InterNACHI estimates about 20 years for a 3-tab asphalt shingle roof, 30 years for architectural shingles and 15 to 25 years for a furnace. These are guidelines only; maintenance and installation quality change the real life.
Can I get insurance on a house with knob and tube wiring?
Often, but it can be harder. The Electrical Safety Authority says many insurers view knob and tube as higher risk, and some may require it to be replaced before they will provide coverage. Get a quote before you firm up an offer.
Does Tarion cover a resale house that is a few years old?
Only for the time remaining. Tarion coverage starts on the original closing date: one year for workmanship, two years for items like water penetration and mechanical distribution systems, and seven years for major structural defects. Furnaces and air conditioners are excluded from the seven-year warranty.
Why do new homes get an extra property tax bill?
MPAC assesses a new home after it is built and sends a Property Assessment Change Notice, typically within three years of moving in. The supplementary bill can go back to the closing date and cover up to two past years, and it is due in one instalment.
What rebates are there for upgrading an older home in Ontario?
The Home Renovation Savings program offers rebates such as $1,250 for attic insulation, up to $7,500 for a cold climate air source heat pump and $100 per window or door opening as part of a bundle. In Toronto, the Basement Flooding Protection Subsidy covers 80% of eligible costs up to $6,650 per property.
This guide is general information, not legal, tax, insurance or mortgage advice. Cost figures marked as assumptions are illustrations, not quotes. Confirm details with licensed contractors, your insurer, your lawyer and the program administrators before you buy or renovate.
Sources
- Tarion, 1, 2 and 7 Year Coverage and Types of coverage after you've taken possession (freehold limits $400,000 / $300,000)
- Save on Energy, Home Renovation Savings (rebate amounts, bundle and single upgrade paths)
- City of Toronto, Basement Flooding Protection Subsidy Program (modified June 18, 2026)
- City of Toronto, Priority Lead Water Service Replacement Program (modified July 31, 2026)
- City of Toronto, Capital Water Service Replacement Program (ownership of service pipes)
- Electrical Safety Authority, Knob and Tube Wiring
- Canadian Underwriter, Managing insurer concerns about knob-and-tube wiring (February 21, 2024)
- Health Canada, Vermiculite insulation that may contain asbestos (archived advisory)
- Town of Milton, Property assessments and supplementary tax bills
- InterNACHI, Standard Estimated Life Expectancy Chart for Homes
- Province of Ontario, Calculating land transfer tax
Featured image: general photo of a detached house from the Local Toronto media library. It is not a GTA property and not a house discussed in this guide.
Local Toronto, HomeLife Landmark Realty Inc., Brokerage.