Buying a Century Old Home in Montreal: What Changes

A house built in 1915 gets visited like any other and bought differently. What changes the file is not the finishes: it is the foundation, the wall nobody opens, the wire behind the plaster, the pipe under the sidewalk, and the window whose model is chosen by a permit. Here is where an ordinary inspection stops being enough.

Century old home: what the phrase means in Quebec

The marker is not sentimental, it is legal. The Insurance Bureau of Canada writes that in Quebec, a house called “old” or “heritage” is a house built before 1940 under the Loi sur le patrimoine culturel, Quebec’s cultural heritage act. It also notes that the “inventoried” status, the one “most commonly assigned,” carries no government conservation requirement. Century old therefore does not mean protected. The mandatory Déclarations du vendeur, the seller’s declarations form, puts the question at D2.9: the property is covered by an act or regulation on heritage protection. Those statuses and their consequences are laid out in buying an old or heritage building. What follows is about the age of the building, not its status.

Period foundation and framing: what a closed wall will not tell you

The seller’s form hands you the vocabulary before the visit. At D5.1, the seller picks the foundation type: stone, wood, concrete block, concrete, or “do not know.” At D5.2, basement problems are declared, among them cracks in the foundation and rot. At D3.1, soil problems: landslide, subsidence, earth movement, instability. At D3.2, work already done to the foundations: pieutage, the driving of steel piles under the footings, and travaux en sous-oeuvre, underpinning.

A crack tells you movement happened. It tells you neither when, nor whether it is still going on. That is the exact limit of a pre-purchase inspection. Under the standard of practice of the Association des inspecteurs en bâtiments du Québec, the AIBQ, Quebec’s building inspectors association, the inspection “is a visual and attentive inspection, which is however not technically exhaustive” (art. 7) and covers components that are installed and readily accessible (art. 8). The inspector describes the foundations (art. 17.1) and probes structural components that appear deteriorated (art. 18), but does not have to enter part of a building if doing so “could cause damage” (art. 11.1), nor to give an opinion on the capacity or expected performance level of the structural system (art. 22.2).

Nobody opens a wall before the purchase. What an open wall reveals: openings enlarged without reinforcement, joists notched to let a pipe through, a repair made with whatever was on hand that day. Active movement, or pieutage already done, is read by a structural engineer, not by a generalist. And before you open, know what the materials contain: Quebec regulation presumes the presence of asbestos until an analysis proves otherwise, as explained in vermiculite and asbestos in a Quebec home.

Knob and tube, fuses: the century old home as the insurer sees it

The Insurance Bureau of Canada puts the age and size of your home into the premium calculation, along with materials, heating and location. And it writes this: an insurer may not offer insurance products for older homes where specific protection requirements apply.

No official source consulted lets me say that a Quebec insurer automatically refuses knob and tube wiring or a fuse panel. What the insurer judges is what you can prove. And the proof exists: the Régie du bâtiment du Québec writes that the electrical contractor or owner-builder must declare to the Régie the work covered by chapter V of the Construction Code, except in particular work “involving a power of not more than 10 kW that does not require replacing or adding wiring.” Ask for the declaration of work and the licence number, not an approximate date. The seller, for their part, answers at D10.2, with the example given: a fuse or breaker that blows repeatedly. One last piece of IBC advice is worth its weight in gold: get from the previous owner the contact details of the company that insured the home. The rest of the file is in hard to insure home in Quebec.

Galvanized plumbing and the entrée d’eau en plomb

Two different problems, often confused. Galvanized pipe gives itself away through the symptoms listed at D9.1: rust in the water, pressure or flow that varies significantly, a pipe that freezes. The inspector describes the materials of the supply and distribution piping (art. 30.1 and 30.3), but does not have to observe water quality (art. 36.4).

The entrée d’eau en plomb, the lead water service line, can be checked and costed. The City of Montreal describes the pipe: grey, it produces no resonance when struck, it scratches, and it does not attract a magnet. The buildings concerned are mostly those of eight dwellings or fewer built before 1970, and the City publishes a screening map by address.

Under by-law 20-030, the owner must replace the private portion within 24 months of receiving the City’s notice of non compliance. When the City carries out the work, the estimated average amount, based on its 2022 to 2025 data, is between $1,200 and $1,400 per linear metre replaced. The bill goes out the following year and can be spread over 15 years on the tax account. Then comes the sentence aimed straight at a buyer: the amount is attached to the building and will be passed on to the next owner if the property is sold. Add that line to your day one costs, which the closing costs calculator totals for you.

With no vapour barrier, insulating badly costs more than not insulating

A wall from 1920 has neither an air barrier nor a vapour barrier in the modern sense. It dries because nothing holds the moisture in. Blow insulation into that cavity and change nothing else, and you move the condensation point inside the wall.

Natural Resources Canada is blunt: insulating must include air sealing, the vapour barrier must be installed on the warm third of the finished wall, and you have to account for the location and condition of old vapour barriers, which may be nothing more than plaster walls covered with several coats of paint. The order of operations is named: deal with moisture or structural problems before insulating. The warning sign is declared at D7.1: has regular and significant condensation ever formed in winter? A check mark next to “walls” is not a comfort detail.

The pre-purchase inspection will not decide this for you. The AIBQ standard requires the inspector to describe the insulation and vapour barrier seen in unfinished spaces (art. 55), then states that the inspector does not have to rule on the building’s compliance with standards, nor on the uniformity, sufficiency or necessity of the insulation (art. 56). An old wall assembly insulated from the inside is designed by a building envelope specialist. For a heritage building, the Régie du bâtiment du Québec does provide a procedure for equivalent or differing measures.

Windows: in a cited building, the permit chooses the model

In Montreal, replacing exterior doors and windows with models of the same dimensions requires a permit in several boroughs, and the underlying rule does not vary: replaced elements must have the shape and appearance of those of the original building, and must also respect the typology of the building, including the type of opening, the subdivisions or the colour. In a heritage sector or site, additional requirements may apply. One borough writes that sliding windows are not permitted in sectors deemed significant.

The fees are published: $9.80 per $1,000 of work, minimum $167.40 for a residential building, non refundable. They go up if the building or the sector has heritage value, and a site planning and architectural integration programme adds fees and delays.

In Laval, roughly 2,600 buildings inventoried between 2015 and 2022 are covered by by-law L-12950: the exterior envelope, the roof, the foundation, the doors and the windows must be in good condition and fulfill their function. The City may require work by written notice, then register a notice of deterioration in the Registre foncier, Quebec’s land register, under section 145.41.4 of the Loi sur l’aménagement et l’urbanisme, the planning act.

No official source consulted puts a figure on the cost of a window. What is verifiable is that the permit restricts the model before your first quote, and that the seller declares any window replacement at D2.11.

Buying a century old home: the expert first, then the negotiation

The AIBQ standard says it in its introduction: visual building inspection is not an expert assessment. Article 10 adds that the inspector must recommend a technically exhaustive examination by a specialist when the signs warrant it.

What is negotiable. The delay first: the inspection condition has to be long enough to fit a second expert assessment. Then the documents: the electrical declaration of work, the water service invoice, the citation by-law if there is one, the name of the previous insurer.

What you budget for. An annual reserve, not a list of jobs. Two items can be costed right now in Montreal: the doors and windows permit and the entrée d’eau en plomb.

Frequently asked questions

My house dates from 1918 and has no status. Can I renovate freely? Not necessarily. The Insurance Bureau of Canada points out that an old house with no status provided for by law may still be subject to municipal regulation. In Montreal, a permit is still required to replace doors and windows in several boroughs. In Laval, roughly 2,600 listed buildings are covered by by-law L-12950.

The inspector wrote “stone foundation in apparently good condition.” Is that enough? That is what the standard asks of them: observe, describe, note the condition. It forbids them from ruling on the capacity of the structural system (art. 22.2) and on remaining service life (art. 12.1). For those two questions, you need an engineer.

The seller says the City replaced the entrée d’eau en plomb. What should I check? The invoice and the date. In Montreal, it goes out the following year and can be spread over 15 years on the tax account: the balance is attached to the building and passes to the next owner.

To go further, read how to choose a home inspector in Quebec and what home maintenance costs in Quebec.

Found a century old home you like and unsure what to demand before you write an offer? Write to me: we will set out the list of documents to ask the seller for and a realistic inspection period for that building.

Georges Matar

Residential Real Estate Broker · RE/MAX DU CARTIER INC.

Contact Georges