Southwestern Ontario · Q3 2026
Furnace renovation cost in London and southwestern Ontario
Equipment, venting, and the gas work behind it. The figures below are modelled for Southwestern Ontario using our 0.98× regional cost multiplier, on a detached home built 1960-1989 at a mid-range finish.
Typical planning budget
$4,350 to $7,050
Typical $5,200 · includes 12% contingency
Before contingency
Why London and southwestern Ontario differs
London and southwestern Ontario prices about 2% below Ottawa, which is the baseline our regional model is anchored to.
- Regional multiplier
- 0.98×
- Versus Ottawa
- -2%
- Province
- Ontario
- Sales tax on services
- HST (13%)
Regional multipliers are anchored to Ottawa at 1.00 and scaled using Statistics Canada's Residential Renovation Price Index and Building Construction Price Index movements by census metropolitan area, then cross-checked against published contractor rate ranges. They are planning-level adjustments, not surveyed local quotes.
Areas this covers
Southwestern Ontario is modelled as a single labour market, so these municipalities share the same cost multiplier:
- London
- Windsor
- Kitchener
- Waterloo
- Guelph
- Cambridge
Somewhere else in Ontario? Compare every Ontario region.
Cost by finish level in London and southwestern Ontario
Finish level moves the number more than almost anything else you control. All three rows use the same London and southwestern Ontario multiplier and the same scope.
| Finish | Low | Typical | High |
|---|---|---|---|
| BudgetStock materials, simple details, value fixtures | $3,150 | $3,800 | $5,150 |
| Mid-rangeCommon homeowner choice: durable materials, better fixtures | $4,350 | $5,200 | $7,050 |
| PremiumHigh-end materials, custom detailing, designer fixtures | $6,400 | $7,750 | $10,350 |
Cost by size in London and southwestern Ontario
Typical all-in planning budgets at three representative sizes, mid-range finish.
| Size | Low | Typical | High |
|---|---|---|---|
| 1,100 sq ft | $3,900 | $4,700 | $6,400 |
| 1,800 sq ft | $4,350 | $5,200 | $7,050 |
| 3,000 sq ft | $5,100 | $6,150 | $8,250 |
Where the money goes
The $5,200 typical figure for London and southwestern Ontario, broken into the lines a contractor quote should also separate.
| Category | Low | Typical | High |
|---|---|---|---|
| Materials | $1,950 | $2,350 | $3,150 |
| Labour | $1,550 | $1,850 | $2,500 |
| Demolition and disposal | $200 | $250 | $350 |
| Permit and design allowance | $200 | $200 | $300 |
| Subtotal | $3,900 | $4,650 | $6,300 |
| Contingency (12%) | $450 | $550 | $750 |
| Total planning budget | $4,350 | $5,200 | $7,050 |
Compared with the rest of Ontario
Same project, same scope and finish, priced against every other Ontario region we model.
| Region | Multiplier | Typical | vs London and southwestern Ontario |
|---|---|---|---|
| London and southwestern Ontario (this page) | 0.98× | $5,200 | — |
| Toronto | 1.15× | $6,150 | +18% |
| GTA (outside Toronto) | 1.10× | $5,950 | +14% |
| Hamilton and Niagara | 1.05× | $5,650 | +9% |
| Ottawa | 1.00× | $5,300 | +2% |
| Northern Ontario | 0.97× | $5,200 | same |
| Other Ontario | 0.95× | $5,100 | -2% |
Permits in Ontario
Building permits are issued by your municipality under the Ontario Building Code. Requirements and fees differ from one city to the next.
Commonly triggered by this project
- Gas appliance work. Gas work must be performed by a licensed technician and may require a permit.
- HVAC changes. Adding or relocating heating, cooling, or ventilation may require a permit and load calculations.
Hiring in Ontario
Ontario does not license general contractors or renovators. Anyone can advertise renovation work, so the paperwork you check matters more than any claimed credential.
Trades that must be certified
- Electrical: Only a licensed electrical contractor may do electrical work for hire. The licence number starts with ECRA/ESA and is searchable.
- Gas and propane: Gas lines, furnaces, fireplaces, and water heaters must be handled by a TSSA-certified gas technician.
- Plumbing: Plumbing is a compulsory trade in Ontario. Ask for a Certificate of Qualification from Skilled Trades Ontario.
- New homes and substantial additions: Building or selling a new home in Ontario requires an HCRA licence. Ordinary renovations do not.
Costs people forget on this project
Included as allowances above. Check any quote covers them too.
- Chimney liner or new venting on a condensing conversion
- Gas line resizing when adding load
- Condensate drain routing and pumps
- Electrical work for a new disconnect or dedicated circuit
- Ductwork undersized for the new blower
- Asbestos-wrapped ducting in pre-1990 homes
Typical schedule: 1 to 2 days for a straight replacement.
Questions homeowners ask
- Why is my furnace quote higher than the advertised price?
- Advertised prices are usually the equipment and a straightforward swap. The lines that move a quote are venting, gas line resizing, condensate drainage, electrical, and ductwork changes. Ask for those to be itemised rather than bundled, because a quote that omits them is not cheaper, it is incomplete.
- Do I need a permit to replace a furnace?
- Yes. Replacing a gas appliance is permitted and inspected work in every province, which is why the permit line above is never zero. A reputable installer pulls it as part of the job. If a contractor offers to skip the permit, that is a reason to end the conversation, not a saving.
- Should I replace the air conditioner at the same time?
- Often yes, if both are near end of life. The indoor coil and blower are shared, so doing both together avoids paying twice for the same access and refrigerant work, and a matched system runs more efficiently than a mismatched one. Price them separately first so you can see what the combined discount actually is.
- Is a heat pump a better choice than a furnace?
- In much of Canada a cold-climate heat pump now handles most of the heating season, with the furnace or electric backup covering the coldest weeks. It costs more up front and attracts the largest rebates of any upgrade on this site. Whether it pencils out depends on your electricity and gas rates, so check the rebates page before deciding.