Renovating an old house is one of the most exciting and complex projects a homeowner can take on. Between preserving the character, bringing systems up to code, and dealing with surprises that pop up the moment you open a wall, the question of budget inevitably sits at the centre of every decision.
Hardwood floors, period mouldings, large luminous windows… that unique charm comes at a price, and it varies greatly from one property to the next. Several factors, such as the building’s age, its condition, its square footage, the scope of the work, and the materials chosen, directly influence the cost of renovating an old house.
Discover the priority work to plan for, the estimated price ranges, the best ways to avoid unexpected costs, and the different ways to finance your renovation. Because renovating smartly also means preserving and increasing the value of your property.
How much does it cost to renovate an old house?
Let's be upfront: there is no universal price for renovating an old house in Quebec, as costs can vary based on dozens of factors. However, you can start your planning with some realistic benchmarks.
Here are three budget scenarios, presented as guidelines, based on the scope of the renovation work envisioned.
These amounts are indicative and may vary depending on the region, the actual condition of the building, selected materials, and contractor availability. Be sure to request multiple renovation quotes to get a reliable figure for your project.
In terms of cost per square foot, light renovations generally range from $50 to $100/sq. ft. For more comprehensive work, this figure can exceed $200/sq ft, depending on the complexity of the project.
Why does an old house often cost more to renovate than a new one?
The answer comes down to one word: surprises. Seemingly sound walls can sometimes hide unpleasant discoveries, like asbestos, mould, lead plumbing, or poor/non-existent insulation. Add to that all the mandatory code updates and non-standard materials that characterize period buildings.
Variables that affect your renovation budget
Several elements can influence the cost of renovating an old house:
Square footage: The larger the property, the more extensive the renovation work.
Age: A house built before the 1940s presents very different challenges compared to a property built in the 1970s or 1980s.
General condition: Renovating a well-maintained building will cost less than one that has been left neglected.
Scope of work: A partial renovation does not require the same resources as a complete rehabilitation.
Materials chosen: Price differences between standard, high-end, or heritage materials are considerable.
Location: Labour costs vary from region to region, as does the availability of specialized contractors.
What are the main types of work to plan for when renovating an old house?
Renovating an old house means setting priorities. Some work cannot wait, as it relates to the safety or durability of the building. Other work is more aesthetic and can be done later.
Here are the six essential budget items to plan for, from structural to finishing work.
1. The roof
The roof is often the first item to assess in an old house. Asphalt shingle roofs – the most common in Quebec – generally last 20 to 25 years. The risk of water infiltration increases rapidly once this threshold is passed.
Warning signs to watch for:
Warped or missing shingles
Granules in the gutters
Moisture stains on the ceiling
A sagging roof structure
Why is it a priority?
The roof is your home's first line of defence! A deficient roof can damage the insulation, the roof structure, and even the foundations of the property.
What is the approximate price range?
Roofing work can cost between $8,000 and $25,000, depending on the square footage, the type of material, and the condition of the roof structure. A prior inspection by qualified specialists can determine whether structural work is also required.
2. The electrical system
Electrical systems in houses built before the 1980s often present safety and insurability issues. Fuse panels, aluminum wiring, and undersized installations are among the most common problems.
Warning signs to watch for:
Circuit breakers that trip frequently
Outlets with only two prongs
Flickering lights
An outdated electrical panel
Why is it a priority?
Several insurance companies refuse to insure homes with a fuse panel or aluminum wiring. Electrical upgrades are often a non-negotiable requirement for insurers.
What is the approximate price range?
Redoing the electrical system of an old house can cost between $8,000 and $20,000, depending on the scope of the work and the square footage of the property.
3. Plumbing
Found in many older homes, lead piping — typically installed between 1940 and 1955 — or galvanized steel piping — installed before the 1950s — poses risks that are well documented today: it can cause corrosion and leaks, as well as contaminate drinking water.
Warning signs to watch for:
Rust-coloured water
Insufficient water pressure
Visibly corroded or cracked pipes
Why is it a priority?
Defective plumbing can cause significant structural damage to a home, sometimes long before it becomes apparent.
What is the approximate price range?
Renovating old plumbing can cost between $5,000 and $20,000, depending on the layout of the house.
4. Insulation and energy efficiency
A poorly insulated old house means energy (and money) escaping through the walls, attic, foundations, and windows. That's why insulation work represents a high-return investment, for both your heating bill and your day-to-day comfort
Critical areas to check:
The attic, generally the top source of heat loss in a home
Exterior walls
Foundations and the crawl space
Doors and windows, whose air-tightness and insulating value deteriorate over time
Good to know
A house that becomes more airtight often requires a mechanical controlled ventilation (MCV) system – commonly called an air exchanger – to maintain good air quality.
Why is it a priority?
Poor insulation translates directly into costly energy losses. In fact, heating accounts for nearly 50% of energy consumption in a Quebec home, according to Hydro-Québec.
What is the approximate price range?
Re-insulating an old house can cost between $5,000 and $30,000, depending on the areas treated and the materials used.
Good to know
Looking for grants to renovate your old house? Quebec’s Rénoclimat program offers financial assistance for insulation work. Check the program details before starting your renos to maximize your savings.
5. Foundations
Foundations are the base of your home. Therefore, delaying repairs could turn a minor problem into a major construction project.
Warning signs to watch for:
Cracks in the foundation walls
Signs of moisture or efflorescence (whitish deposits on the foundations)
Doors and windows that stick
Sagging floors
Why is it a priority?
Some foundation cracks are cosmetic only, while others reveal a serious structural problem. It is therefore important to call in a structural specialist to get an accurate diagnosis.
What is the approximate price range?
The cost to renovate an old house’s foundations can range between $10,000 and over $50,000, depending on the nature and extent of the problem.
6. The kitchen and bathroom
Did you know that the kitchen and bathroom are the two rooms offering the best return on investment in renovation? They are also the rooms where aesthetic choices most influence the perceived value of a property.
What is the approximate price range?
Kitchen renovation can cost between $15,000 and over $60,000; the price varies based on several elements such as cabinets, countertops, and appliances.
Bathroom renovation generally ranges between $10,000 and $30,000, depending on the square footage and the finishes chosen.
Good to know
Whether for a kitchen or bathroom renovation, the materials you choose – such as ceramic, hardwood, or quartz – significantly affect the final bill.
Should you renovate everything at once or work in phases?
This is one of the most frequently asked questions by those planning to renovate an old house. Both approaches have advantages and disadvantages.
How to avoid unpleasant surprises when renovating an old house?
It's perfectly normal to fear unexpected costs when thinking about renovating an old house. It's actually one of the main obstacles that stops people from getting started. The good news is that unpleasant surprises are largely avoidable with the right precautions. Here are a few of them.
1. Have the property inspected before starting work
The pre-renovation inspection of an old house is a step that is too often overlooked, yet so important.
Unlike the pre-purchase inspection, which provides a general overview of the property, the pre-work inspection aims to establish a precise technical diagnosis in preparation for the upcoming construction project. These are two complementary but not interchangeable steps.
Who to consult?
A building inspection specialist to assess the general condition
A structural expert to check the foundations and roof structure
A master electrician to evaluate the electrical panel
The diagnoses from these specialists help avoid many surprises and cost overruns during construction.
2. Plan a budget reserve for unexpected costs
It is generally recommended to set aside a contingency margin representing 15% to 20% of the total project budget.
For example, if your estimated budget is $80,000, you should keep between $12,000 and $16,000 in reserve. You'll be glad you planned such a financial cushion if you discover mould behind a plaster wall or contaminated mineral wool in the attic.
A realistic renovation budget always includes such a safety margin. Projects that neglect it are the most likely to go off the rails.
3. Get multiple quotes and compare your options
Obtain a minimum of three different quotes for the same work before making your choice. This allows you to compare prices, as well as evaluate each contractor's approach and the quality of their communication.
What to check before signing
Does the contractor hold a licence from the Régie du bâtiment du Québec (RBQ)?
Is their civil liability insurance current?
Are references from previous clients available?
Is there a written renovation contract detailing the work, timelines, and payment terms?
How to finance the renovation of an old house?
Financing often determines the feasibility and scope of a renovation project. Several grants and financing options are available in Quebec, depending on your financial situation and the nature of the planned work.
Main financing options
Home equity line of credit: The ideal option for large-scale projects. It uses the equity in your property as collateral and generally offers an advantageous interest rate.
Personal renovation loan: A suitable solution for mid-sized projects that does not require mortgage collateral.
Mortgage refinancing: This option allows you to include renovation costs in your existing mortgage, with a single monthly payment.
Renovation grants available in Quebec
The Quebec government's Rénoclimat program offers grants for insulation, doors and windows, and energy-efficiency work.
Hydro-Québec's LogisVert program offers financial assistance for the installation of heat pumps and the reduction of electricity consumption.
Certain municipal programs also offer additional assistance for the renovation or code compliance of heritage buildings.
Certain tax credits for property renovation may be available through Revenu Québec — check your options for the current year.
Good to know
The Desjardins advisory team is there to help you evaluate the most suitable financing solution for your renovation project. Consider consulting them before choosing your financing method.
RenoAssistance by Desjardins: the solution for your renovation project
Finding a reliable contractor, obtaining comparable quotes, prioritizing the work to be done, estimating costs… renovating an old house requires a lot of time and planning, which can generate its share of stress! It is precisely to address these challenges that RenoAssistance by Desjardins has been supporting Quebec homeowners for over 20 years.
Everything you need to get the job done
Access to a network of verified contractors with RBQ licences, insurance, and systematically validated references
A completely free support service, from project assessment to the end of construction
Assistance comparing renovation quotes to make an informed decision
Project follow-up and support in case of problems or disputes
Complete expertise for all your projects: roofing, plumbing, electrical, insulation, foundations, kitchen, bathroom, and more
Whether for a partial renovation or a complete rehabilitation, RenoAssistance by Desjardins connects you with the right resources at the right time.
Renovating an old house: a project that requires preparation, not improvisation
Estimating the renovation cost of an old house is not always straightforward, as it depends on several factors: the actual condition of the building, the priority work to undertake, and the materials chosen, all of which can vary from one property to the next.
What is certain, however, is that all renovation projects that go well share common traits: a serious upfront inspection, a budget that includes a contingency margin, and support from verified specialists.
With the right preparation, renovating an old house is much more than an ambitious project — it's a dream opportunity to add value to a property with real character!
Get free quotes from qualified contractors
