Quebec House Construction Features

A buyer touring their first property in Montreal or Laval always notices the same things: the staircase bolted to the façade, the basement finished as a family room, the roof that looks flat, the pump sitting in a hole in the floor. None of it is folklore. Each one comes from the climate or from a by-law, and each one can be verified before the offer.

The features of a Quebec house start with the housing stock

At the 2021 census, Montreal counted 816,340 occupied private dwellings, of which 58,065 were single detached houses, roughly 7%. Apartments or flats in a duplex accounted for 107,565 dwellings, and apartments in a building of fewer than five storeys 464,420, close to 57% of the total. Laval reverses the picture: of 169,785 dwellings, 76,010 are single detached houses, roughly 45%.

The age of the stock separates the two cities too. In Montreal, 293,880 dwellings date from 1960 or earlier, about 36% of the stock. In Laval, the largest cohort runs from 1961 to 1980. Comparing the two means comparing two eras of construction. The extreme case is covered in buying a century old home.

The outside staircase is a regulated component, not an ornament

In Montreal, a permit is required to build, alter or replace an outside staircase or any of its components. Maintenance, such as replacing a single tread, does not require one, except in certain heritage sectors.

The standards are specific. The staircase must sit at least 1.2 m from the property line. Treads and risers must meet the dimensions set out in the Code de construction du Québec. Non-combustible materials may be required in a building of more than two dwellings. And no alteration may reduce the safety of the staircase. The fees: $9.80 per $1,000 bracket of work, minimum $167.40 for residential.

The sector changes everything. In its heritage guide, the borough of Mercier-Hochelaga-Maisonneuve reminds owners that any work touching an architectural feature visible from the public way requires an authorization, and it names the replacement of balconies, staircases and guardrails, whose traditional height it sets at 36 inches. A staircase redone without authorization becomes a compliance problem that follows you to resale.

The lived-in basement, and the cour anglaise that makes it possible

Living in the basement is normal here, and it is a construction choice, not a patch job. To give it an independent entrance, you dig a cour anglaise, a sunken areaway. In Villeray-Saint-Michel-Parc-Extension, the City sets its minimum dimensions: 1.5 m long and 1.5 m wide, at least 1 m from the front lot line, except for the stairs. A guardrail at least 80% open is required for any single vertical drop of more than 0.6 m.

The detail that matters most is drainage: the low surface must be drained by a discharge pipe that carries rainwater to a retention sump located inside the building. And if the cour anglaise gives access to an additional dwelling in the basement, that dwelling must comply with construction and zoning standards. Inside, a permit becomes necessary as soon as the work touches the foundations, the structure or the walls, or changes the dimensions, the division or the use of the rooms. According to the Régie du bâtiment du Québec, a carbon monoxide alarm is mandatory as soon as there is a combustion appliance or a direct access between the dwelling and an indoor parking garage.

The flat roof, and what it imposes on the owner

The flat or low slope roof dominates the central neighbourhoods. Replacing its covering requires a permit, and the materials are not a free choice: several boroughs allow only a white material, a reflective coating, white gravel, or a minimum solar reflectance index. That threshold runs from 56 to 82 depending on the borough, and the requirements do not apply to the portions occupied by mechanical equipment or by a terrace.

The useful question is not aesthetics, it is the date. The Déclarations du vendeur sur l’immeuble form asks for the type of covering, including bitumen and gravel and elastomeric membrane, its year of installation and the documents attesting to its replacement. It also asks whether ice or icicles have ever built up regularly along the roof edge. A yes on that line is talking about attic insulation and ventilation, not about the weather.

A plex is a form of construction and a contract at the same time

A duplex or triplex occupied by tenants is not a house with extra rooms. It is a building governed by the Tribunal administratif du logement (Quebec’s rental board), where the tenant has the right to maintain occupancy: they may stay in the dwelling as long as they wish, provided they meet their obligations.

Rent, for its part, has a memory. The landlord must state the lowest rent paid during the preceding twelve months, in section G of the mandatory lease. A new tenant who pays more may ask the Tribunal to fix the rent, and the Tribunal may adjust it retroactively to the start of the lease. A purchase price built on recently raised rents therefore rests on sand. To find out what your lender will retain from that income, start with the affordability calculator, then confirm with a mortgage broker.

Showings have to be planned. An owner who is selling has the right to show the dwellings to a prospective buyer, on three conditions: 24 hours of notice before each visit, which may be verbal, visits between 9 a.m. and 9 p.m., and the tenant’s right to require being accompanied. The seller’s form reveals the rest: short term rental of less than 30 days, notice of family residence, benefits not written into the lease, an open file at the Tribunal, and the presence of a tenant aged 70 or over who has lived in the dwelling for 10 years or more. The rest is in buying a triplex in Laval.

Foundation drain, sump and backwater valve: the basement trio

These three pieces get confused constantly. The drain français, the foundation drain, rings the footing. The sump pump empties a pit. The backwater valve stops the municipal sewer from coming back up into your home.

In Montreal, since 2011, backwater valves must be installed in all new buildings, under the Règlement sur la protection des bâtiments contre les refoulements d’égout (11-010). They go on the discharge piping of each fixture or group of fixtures in the basement, floor drains included. The City recommends checking twice a year that they work and are not obstructed. The RénoPlex program grants $80 for a normally closed valve, $560 per valve installed under an existing slab and $1,500 for a retention sump with a pump system, for eligible buildings of one to five dwellings.

In Laval, by-law L-11870, which repealed and replaced the former by-law L-5057, also covers existing buildings. Every owner must install backwater valves, of the normally closed type only, on all discharge branches located below the crown of the street; a building already standing had 18 months after the by-law came into force to comply. A floor drain with a built-in device does not exempt the owner from an independent valve, no valve may be installed on the main building drain, and maintenance is required at least once a year. If these devices are missing or poorly maintained, the City is not liable for damage to the building or its contents.

The City of Montreal also says to send gutter water onto a permeable surface without connecting it to the foundation drain. The seller’s form follows the same logic: it asks whether the building has a sump, a sump pump, with its operating frequency and year of installation, and a foundation drain, specifying whether a system exists to reach it for inspection and cleaning. The seasonal mechanism is explained in spring melt and water infiltration.

Electric heating and heat pumps: what Quebec construction assumes

Statistics Canada sums up the Quebec situation in two figures: 58% of Quebec households report heating with electric baseboards and 7% with electric radiant heating. Hence houses with no ducts, and therefore no central air conditioning from the start. The wall-mounted heat pump is an addition, not standard equipment.

The residential rate has two tiers. Under Rate D, in force since April 1, 2026, Hydro-Québec bills 46.154 cents per day of network access charges, then 7.065 cents per kilowatt hour up to 40 kWh per day and 11.142 cents for the rest. The dual energy Rate DT requires a central system that switches to a fuel below -12 °C or -15 °C depending on the zone: 5.131 cents above the threshold, 30.001 cents below. The LogisVert program pays $50 per 1,000 BTU/h at -8 °C for an ENERGY STAR certified heat pump and $120 for a cold climate model. The $140 measure for a very high efficiency heat pump was withdrawn from the program on August 25, 2025: only work done before that date still qualifies. Rates checked again on October 31, 2026 and revised every April 1; LogisVert amounts as posted by Hydro-Québec on October 31, 2026.

Three questions on the seller’s form frame the subject: the energy source of the main heating system, the oil tank and its year, the wall-mounted or central heat pump and its year. On oil, the Régie du bâtiment specifies that section 8.05.01 of the Code de construction adopts standard CSA B139 by reference.

Windows follow the same logic. The City’s heritage lexicon distinguishes the casement window, the fenêtre à crémone, from the sash window. This is not a style debate: the seller’s form asks whether regular and significant condensation has ever formed in winter, with windows as the first box.

What these features change at the inspection

The Déclarations du vendeur sur l’immeuble form (DV 00001) covers a mainly residential building of fewer than five dwellings, excluding divided co-ownership. It is built like this article: one section per feature.

Two sections close the form. D13 asks whether the building has ever been inspected, whether the reports are available, and which expert assessments were done: pyrite, pyrrhotite, radon, ochre deposit, asbestos, foundation drain. D14.4 asks whether major work was done and whether permits were issued for each.

During a showing, the point is to connect each ticked box to what the inspector will have to look at. A pump that runs often, a foundation drain with no access port and a roof with no invoice make one file, not three anecdotes.

Frequently asked questions

Does a finished basement count in the living area? No official source consulted here settles it with a single rule. Ask on what basis the advertised area was calculated, then compare properties measured the same way.

Can I rent out the basement of the house I am buying? Not automatically. In Montreal, an additional dwelling in the basement must comply with construction and zoning standards, and work that changes the division or the use of the rooms requires a permit. Confirm the zoning before you build a budget on that income.

Is a flat roof a bad sign? No, it is the norm in several central neighbourhoods. What matters is the year of the covering, the invoices and the history of ice at the roof edge, three items the seller has to declare.

Is a backwater valve mandatory in an older house? In Montreal, the installation requirement applied to new buildings from 2011. For an existing building, the City insists on verification, access and maintenance, and it subsidizes installation. In Laval, by-law L-11870 also covers buildings already standing, which had 18 months to comply. Confirm your own case with your borough or your city, and with your insurer.

To go further, read the seller’s declaration in Quebec and how to cut your heating bill in Quebec.

Touring properties and not sure what to look at first? Write to me. We do the visit together, in French, English or Arabic, and we write down what will have to go to the inspector.

Georges Matar

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

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