Can you sell a house with work done without a permit in Montreal?

Can you sell a Montreal house when past work was done without a permit?

Yes. No sentence cited on this page forbids the sale because a finished basement, an extension, a deck, or other work was done without a borough permit, or because you cannot find the paper. What the sale does not skip is saying what you know. The administrative codification of the By-law concerning the construction and conversion of buildings, 11-018, is dated 2 September 2025 and says it was prepared only for the reader’s convenience and has no official value. The sentences below are that text. A notary, or the borough, reads the official by-law and each amendment (codification of by-law 11-018, 2 September 2025, page in French).

Article 32 of that codification says it is forbidden to do the following without a permit: the construction of a building; the transformation of a building in the sense of the Code; the modification, replacement or addition of a construction element of a building covered by a zoning by-law, a site-planning and architectural-integration plan, or any other municipal regulation; the relocation of a building; the installation of a mobile home; and bringing a building into conformity. Article 1 defines “Code” as the National Building Code of Canada 2010, as adopted and amended, also called the Quebec Construction Code, chapter B-1.1, r. 2, Chapter I, Building. Article 32 names a transformation in the sense of that Code. This page does not add a definition article 1 does not give. No sentence in article 32 says a deed waits for a permit.

Which past work does the City’s page put on the permit side, and which does it not?

The City’s page on interior work, updated 2 February 2026, is the plain list. The block shown before a borough is chosen says a permit is not required for some minor aesthetic work. Its examples are changing a floor covering, painting the walls, replacing cabinets, replacing counters, and replacing a sink or a bath. The same block says a permit is required, however, if the work touches the foundations, changes the structure of the dwelling, changes a wall whether it is load-bearing or not, or increases the floor area. A later block on the same page, for Ahuntsic-Cartierville, keeps foundations, structure and floor area in that “however” sentence and does not repeat the wall clause. Both of those blocks then say you need a permit for work that touches the walls or the foundations of a dwelling, and that a permit is also necessary for any work aimed at changing the dimensions, the division or the use of the rooms. This page does not copy every borough block, and it does not decide that a given finished basement is one of those sentences (Interior work on a building, City of Montréal, updated 2 February 2026, page in French).

The same page, in the block before a borough is chosen and again in the borough blocks read here, says the City no longer issues a permit for plumbing, for electrical work, or for electric or gas heating. It says you must still comply with the provincial regulation, and that questions go to the Régie du bâtiment du Québec. A missing borough permit for those three is not, on that page, the same fact as work the page says needs a permit. This page does not state what the Régie requires.

An extension is a different page. The City’s page on extending a building, updated 6 February 2026, says that before the work a construction permit is necessary, and that before you start the steps you can ask the permit counter for information (Obtenir un permis pour l’agrandissement d’un immeuble, updated 6 February 2026, page in French). A deck, a balcony, a veranda or a stoop is another page, updated 11 February 2026. Its overview says that, in most cases, a permit is not required to maintain one, and that, with rare exceptions, you must get a permit before building, extending, altering or replacing one. A borough block on that page is not the same rule: one block says a permit is not required when the floor is less than 60 cm from the ground, and is required when the floor is more than 60 cm. This page does not pick one block as the rule for the Island (Building or replacing a terrace, balcony, veranda or stoop, updated 11 February 2026).

Article 33 of the codification is the narrow exception to article 32. A permit is not required to install or build a temporary building on a site, needed for the construction work or used for the sale or rental of dwelling units, or to install, build or extend a secondary building whose total area is at most 15 m². That second case is the codification’s. It is not a sentence that every shed, every deck or every finished room was outside article 32.

What does the by-law say about work that was already done?

Article 34 says the application article 32 requires is made by the owner or the owner’s mandatary. It identifies the lot, describes the projected work, and, where a mandatary files it, is accompanied by the owner’s power of attorney. For a divided co-ownership, the applicant provides the syndicate’s authorization for work to be carried out in a common portion. Subparagraph 7 b) ii) says an application to extend the area of an existing building is accompanied by a certificate of location. Those are the papers of an application. They are not a promise that a permit issues for work already finished. This page does not ask anyone to file that application.

Article 55 is the sentence about work already done. The competent authority may, by a notice, order the owner of a building built or modified without a permit, or contrary to a permit issued under article 38, to file an application for the required permit, within a period of at most 10 days that the notice sets. Article 56 says the authority may, by a notice, order the owner or any other interested person named in the article to suspend construction work done without a permit, not in conformity with the permit, or not in conformity with municipal regulation. Article 61 says the authority may, by a notice, order the owner of a building or a construction that does not conform to the applicable municipal regulation to make it conform or to demolish it, within a period the authority sets, of at most 90 days. Those are powers the codification writes. This page does not suggest that anyone demolish, make a building conform, or do work, and no sentence in those articles says the deed waits for the notice.

The extension page says you can ask the permit counter for information before you start an extension. The interior page sends plumbing, electrical work, and electric or gas heating to the Régie du bâtiment du Québec. This page does not ask anyone to apply for a permit after the fact, to file papers with the borough, or to do work. What you can say, if you know it, is what was done, about when, by whom, and whether you have a permit paper, an invoice or a plan. A missing paper is a fact you can say.

A minor variance is a different path, and it is not a permit for work that never had one. Article 145.5 of the Act respecting land use planning and development says the resolution may also have effect for work in progress or already carried out where the work was authorized by a building permit and was carried out in good faith (Act respecting land use planning and development, section 145.5). The City’s page, updated 8 June 2026, says that in some cases a variance « peut servir à légaliser des erreurs survenues au moment de la construction », but that a permit must have been issued at the outset and the work done in good faith (Demander une dérogation mineure, updated 8 June 2026, page in French). Québec’s guide, last updated 5 October 2026, says the variance cannot be granted if the work was done without a permit (Règlement sur les dérogations mineures, guide, last updated 5 October 2026, page in French). This page does not decide that a given file is article 145.5. This page does not ask anyone to apply for a minor variance.

What do you declare, and what papers show it?

On the French PDF read for this page, marked DV 00001 and V24, copyright 2012 and 2022, the answers are to your knowledge and in good faith. The form says it must be used when a brokerage contract for the sale of an immovable is made with a private individual, for a chiefly residential immovable of fewer than 5 dwellings, excluding divided co-ownership. On a sale that is not made under that contract, you still say what you know, in writing. How that sale runs is How do you sell a house without a real estate broker in Quebec?. The form’s opening names, among the documents you provide, invoices, plans, specifications and permits (Déclarations du vendeur sur l’immeuble, form DV, page in French).

D14.4 asks whether, in addition to what is already mentioned, important work has been done. The examples on the form are a change to the division of the rooms and a change of floor covering. If the answer is yes, the detail goes at D15, and the form asks whether plans and specifications were prepared and whether the required permits were issued for each of those works. A finished basement, an extension or a deck is not one of the examples printed at D14.4. This page does not decide that each of them is important work under that question. D2.11 asks whether, since you acquired the property, there has been an addition, a replacement or a modification, notably of windows, a pool, a shed, a sidewalk, a paved driveway, fences, a gallery, a terrace, hedges, low walls, or other. The note under D2.11 says a positive answer to D2.8, D2.9, D2.10 or D2.11 may mean a new certificate of location is required if the one provided does not reflect those changes. That note is the form’s. D15 is the place, the year, and how the situation was dealt with, if it was. D14.5 asks whether anything else could affect the value, the income, the expenses or the use. The form asks that question. This page does not answer it with a figure, and it does not say that past work raises or lowers a price.

One bullet of D2.9 asks whether urban-planning regulations limit the use of the immovable, and it names zoning, subdivision, construction, and conditions for obtaining a permit, or another limit. Article 1725 is the warranty that uses the form’s phrase for a public-law restriction. The seller of an immovable warrants the buyer against any violation of public-law restrictions affecting the property which are exceptions to the ordinary law of ownership. The seller is not bound to that warranty where notice of those restrictions was given at the time of the sale, where a prudent and diligent buyer could have discovered them by reason of the nature, location and use of the premises, or where such restrictions have been registered at the Land Registry Office (Civil Code of Québec, article 1725). This page does not decide that work done without a permit is that kind of restriction, or that it is registered. A notary reads that.

What does a certificate of location show about a permit?

The City’s page on permit documents, updated 4 September 2025, says a certificate of location shows the dimensions of the lot, the identification of the lots, and the siting of the building or buildings. It says a new one may be required every 10 years, and that if you have made additions, its examples being a shed or a pool, since you became the owner and they do not appear on the current certificate, you will have to provide a new one. It says a land surveyor produces it. That list does not name a borough permit, and it does not say the certificate states whether one was issued (Comment obtenir les documents nécessaires à une demande de permis, updated 4 September 2025, page in French).

The Ordre des arpenteurs-géomètres du Québec says there is no statute or regulation that would make a certificate of location expire. It says an extension of the house, building a garage, a pool or a shed, or adding a fence or a hedge, are modifications for which a new certificate would be required, so the position can be checked against the municipal minimum distances for the pool and the shed, and so fences can be checked for an encroachment on the neighbouring properties. A finished basement is not in that list. This page does not decide that interior work leaves the certificate unchanged (Durée de vie du certificat de localisation, page in French). Québec.ca, updated 15 October 2025, says the certificate is necessary for any real estate transaction, that a land surveyor produces it, and that the person selling generally provides it to the buyer. The same page says it is mainly a plan and a report in which the land surveyor gives an opinion on the current situation and condition of a property as to the titles, the encroachments, and the laws and regulations that may affect it. It says you will find, where they apply, servitudes, flood zones, risk zones, or municipal restrictions that prevent a pool or a shed. Those lists do not name a permit, and they do not say the certificate states whether one was issued (Certificat de localisation, Québec.ca, page in French).

Article 57 of the codification is a certificate inside a permit file, not a history of every permit. For the construction or the ground-level extension of a principal building, the owner must, within 30 days after the foundations are in place, provide the competent authority with a certificate of location prepared by a land surveyor, including any other measurement that lets the authority check whether the work conforms to the applicable municipal regulation. Article 34’s certificate, for an application to extend an existing building, is a paper attached to that application. Neither article says the certificate lists the permits issued for past interior work.

Can you sell with the work as it is, and without the legal warranty?

Two paths are not the same promise. You can sell with the work as it is, and say what you know, on the form when that form is used and in writing when it is not. Selling without the legal warranty is a clause in the promise and the deed. It does not cover a problem you knew and did not disclose. Article 55’s notice, when the authority sends one, is the by-law’s. No page cited here says the deed, or the choice of buyer, erases it.

Article 1726 is the warranty of quality. The seller warrants that the property and its accessories are, at the time of the sale, free of latent defects which render it unfit for the use for which it was intended or which so diminish its usefulness that the buyer would not have bought it or paid so high a price if he had been aware of them. The seller is not bound to warrant a latent defect known to the buyer or an apparent defect. An apparent defect is one that can be perceived by a prudent and diligent buyer without any need of an expert (Civil Code of Québec, article 1726). This page does not decide that work done without a permit is a latent defect. Article 1728, in the text in force since 1 May 2014, says that if the seller was aware or could not have been unaware of the latent defect, he is bound not only to restore the price, but also to make reparation for the injury suffered by the buyer (article 1728).

Article 1732, in the text in force since 6 April 2016, says the parties may, in their contract, add to the obligations of legal warranty, diminish its effects or exclude it altogether, but in no case may the seller exempt himself from liability for his personal acts or omissions (article 1732). Article 1733 says a seller may not exclude or limit his liability unless he has disclosed the defects of which he was aware or could not have been unaware and which affect the right of ownership or the quality of the property. An exception may be made to this rule where a buyer buys property at his own risk from a seller who is not a professional seller (article 1733). The exception is not a permission to stay silent. Éducaloi says that, if the exclusion is real, you cannot sue for a hidden defect, and what remains is to show that the truth was voluntarily hidden on a point so important that the buyer would not have bought, or not at the same price. Éducaloi also says the legal warranty cannot be invoked for a problem that was declared in the seller’s declaration (Immobilier : acheter sans garantie légale, page in French). The OACIQ says the legal warranty waiver will not protect the seller against legal action for defects of which he was aware and which he should have disclosed (The legal warranty of ownership and quality). How the clause is written is the as-is page already cited. A notary or a lawyer reads the clause. This page does not.

A direct sale is a further path. Bruce Malcolm buys houses himself on the Island of Montreal and the surrounding areas. He holds no broker, agent or appraiser licence, and he is not an advisor. There is no inspection and no commission. An offer with no inspection condition does not, by itself, set aside the legal warranty of quality. You say what you know about the work when you send the address: what was done, about when, whether you have a permit paper, an invoice or a plan, or that you do not know. He does not apply for a permit, and he does not do the work. The closing date is one you choose once the notary can sign. Sending the address starts a conversation (request an offer). The form does not commit you. A notary or a lawyer reads the deed.