You found your dream century home and your conditional offer has been accepted. But after receiving your home inspector’s report, it turns out your charming Victorian cottage is more like an old house that needs more than a fresh coat of paint.
While this doesn’t necessarily mean you need to back out of the deal, it’s important to understand what the repairs could involve and how they might affect your budget. Depending on the conditions of your offer, you may also have an opportunity to head back to the negotiating table.
Your REALTOR® can help you understand the findings in your home inspection report, determine what questions to ask and, where appropriate, recommend getting more information or quotes from qualified professionals before moving forward.
In this article, we’ll go over the most common renos or repairs you’ll need to consider when buying an older house, such as:

“Disposable” systems that need replacing
Roofs, air conditioners, furnaces and boilers don’t last forever. With an older home, there’s a chance at least one of these systems could be approaching the end of its useful life.
That doesn’t necessarily make it a “bad” house. But knowing which major components might need to be replaced soon can help you plan for costs that could otherwise come as an unwelcome surprise.
💲Expect to pay:
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- Between $5,000 and $15,000 for an asphalt roof. HomeStars’ 2026 Canadian roofing cost guide estimates asphalt roof installations typically fall within this range, although roof size, materials, pitch and other project requirements can push costs higher.
- About $4,100 to $9,500 for a new gas furnace. Home Depot Canada estimates furnace supply and installation in Canada can fall within this range, with an average of about $6,800. The final cost depends on factors including the size and layout of the home, furnace type, ductwork and installation requirements.
- Approximately $11,750 and up for a new natural gas boiler in Ontario. Enercare’s 2026 boiler guide says installation of a new natural gas boiler starts at about $11,750, including the unit, standard installation and required licences, permits and code requirements. Boiler type, efficiency, fuel source and the home itself can all affect the final price.
- About $5,000 to $8,000 for central air conditioning. Home Depot Canada estimates the cost to supply and install a central air conditioning system in Canada generally falls within this range, with an average of about $5,500 for its benchmark system.
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Note: These figures are budgeting estimates from the cited Canadian sources. Actual costs can vary significantly depending on where you live, the size and condition of the home, the equipment or materials selected, accessibility, permits and the scope of the work. Get quotes from qualified local professionals for the home you’re considering.

Foundation cracks and sloping floors
Nobody wants to move into an old house with serious foundation problems, but finding a crack doesn’t automatically mean you’re facing a major structural repair.
Some foundation cracks are relatively minor and can be repaired or sealed. Others can be associated with water infiltration, movement or structural issues that require much more extensive work.
That’s why signs such as significant cracks, uneven or sloping floors, doors and windows that no longer sit square, or evidence of movement may warrant further investigation by an appropriate qualified professional.
HomeStars’ 2026 Canadian foundation repair guide shows just how much the severity of the problem can affect the price. A straightforward crack repair can cost hundreds of dollars, while stabilization or other major structural work can cost tens of thousands.
💲Expect to pay:
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- About $300 to $800 for a minor crack repair, or $500 to $1,500 for a typical crack injection. HomeStars estimates structural crack repairs can start around $1,200, while a structural problem requiring foundation stabilization can range from about $5,000 to $50,000 or more, depending on the problem and repair method.
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Plumbing and electrical elements
An old house can still contain electrical and plumbing systems that have since been replaced by newer materials and standards, including knob-and-tube wiring, galvanized steel supply pipes and cast-iron drain pipes.
One of the challenges is that previous renovations don’t always tell the whole story. A basement or kitchen may have newer electrical wiring or plumbing, while older systems can remain behind finished walls on upper storeys.
Access can make a major difference to the cost. Fishing new wiring through finished plaster walls or replacing pipes hidden inside walls and ceilings can require considerably more labour than doing the same work during an open-wall renovation.
💲Expect to pay:
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- About $8,000 to $20,000 or more for a whole-home electrical rewire in Ontario. City Power Electrical Services, an Ontario licensed electrical contractor, estimates a full rewire of a small-to-mid-sized home with good access at about $10,000 to $16,000. A larger finished home with plaster walls can cost $18,000 to $25,000 or more.
- About $8,000 to $15,000 or more to repipe a typical 1,500-square-foot older Toronto home. Mr. Rooter Plumbing of Toronto uses that range for complete repiping in homes in Toronto’s Annex neighbourhood, where heritage plaster, original woodwork and multi-storey layouts can make access more difficult.
- About $2,800 to $4,800 for a cast-iron plumbng stack replacement. Premier Plumbing’s 2026 pricing guide (serving the Toronto area) uses this range for replacing the main vertical cast-iron drain stack, with the scope and accessibility of the damaged pipe affecting the final cost.
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Windows
Just because your home inspection reveals a house still has older windows doesn’t necessarily mean they all need to be replaced immediately.
Their condition, operation, air leakage and energy efficiency can all factor into that decision. Some homeowners also choose to replace functioning windows because they want easier operation, improved energy efficiency or a different look.
💲Expect to pay:
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- About $300 to $1,000 per window installed for a standard replacement. According to HomeStars’ 2026 Canadian window installation guide, a standard vinyl single-hung window typically costs $300 to $600 installed, while double-hung and casement windows generally range from about $400 to $900. Larger, custom or structurally complicated windows can cost considerably more.
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Other things to look for in an old house
Other issues a home inspector might recommend further investigation for in an older house include the possible presence of lead-based paint, mould or asbestos-containing building materials.
Health Canada says asbestos was commonly used in building products before 1990, including insulation, cement and plaster, siding and floor and ceiling tiles.
Asbestos-containing materials that are in good condition and left undisturbed generally don’t present the same risk as material that is being cut, removed or disturbed during renovations. Health Canada recommends having suspected materials professionally tested before major renovation or demolition work and hiring a qualified asbestos-removal specialist if asbestos needs to be removed.
Lead paint is another consideration in older properties. According to Health Canada, a home built before 1960 probably contains lead-based paint, while homes built between 1960 and 1990 may have lead-based paint on exterior surfaces and smaller amounts on some interior surfaces. If you think paint may contain lead, Health Canada recommends having it tested rather than sanding, scraping or otherwise disturbing it.
When it comes to mould, Health Canada generally does not recommend routine air testing. A visual inspection for mould, moisture and signs of water damage is usually more useful, although a qualified professional may recommend additional testing where a moisture or mould problem remains unexplained.
If your home inspection report includes a number of issues, remember it doesn’t automatically mean the home is off the table. The important thing is understanding what you’re dealing with, what needs attention now versus later, and what it could mean for your budget.
Your REALTOR® can help you navigate the information, ask the right questions and decide what makes sense for you before moving forward with buying an old house.
The article above is for information purposes and is not financial, legal, construction, engineering or other professional advice, or a substitute for advice from qualified professionals. Prices are estimates published by the sources cited and may vary by location, property, materials and scope of work.


























