A major plex renovation — a new roof, reconfiguring a unit, replacing windows, bringing electrical up to code — can add real value to your income property… or turn into a nightmare. The difference comes down to four things: getting the right municipal permit, hiring an RBQ-licensed contractor, signing a solid written contract and understanding your warranties. At ImmoMulti, a direct buyer of multi-unit properties on the North Shore, we see too many owners overpay for poorly managed work. Here, from the owner's side, is how to secure a major renovation project in Quebec.
When is a municipal permit required to renovate a plex?
A construction or renovation permit is generally required as soon as work affects the structure, an addition, splitting a unit, plumbing, electrical, the roof, windows or the exterior appearance. Requirements vary from one municipality to the next.
The first step of a major renovation doesn't happen on the job site — it happens at the counter of your city's urban planning department. Each North Shore municipality — Terrebonne, Mascouche, Blainville, Boisbriand, Saint-Eustache, Deux-Montagnes — has its own planning by-law that determines which work requires a permit or a certificate of authorization. Like-for-like routine maintenance may be exempt, but work that alters the structure, adds floor area, changes the number of units, or modifies the exterior appearance almost always needs authorization.
Doing major work without a permit is a risky bet: fines, an order to restore or demolish, and — above all — a problem that resurfaces at sale time. A careful buyer, or their notary, will ask to see the permits. Undeclared work can also jeopardize an insurance claim. To gauge real permit-file timelines, see our guide on construction permit delays for a plex on the North Shore.
Reference: permit issuance rules are set by each municipality; check with your urban planning department. See also the Régie du bâtiment du Québec (RBQ) for the framework governing construction work.
How do you verify your contractor's RBQ licence?
In Quebec, a contractor who performs construction work for others must hold a licence from the Régie du bâtiment du Québec (RBQ) covering the relevant categories and subcategories. The good news: this check is public, free and takes two minutes.
Verify a licence in 4 steps
- Search the RBQ Register of licence holders by name or licence number.
- Confirm the licence is valid and active, with no suspension or restriction.
- Check that the subcategories actually cover your work (general, carpentry, plumbing systems, etc.).
- Get the licence number in writing and require it on the contract and invoices.
A contractor who hesitates to give you their licence number, or whose licence doesn't cover your work, is a red flag. Dealing with an unlicensed contractor leaves you with little structured recourse if the work is defective.
What written contract should you sign?
The written contract is your best insurance. A serious contractor will propose a detailed agreement on their own; be wary of one who wants to work "on a handshake" or demands a large cash deposit before starting. Your contract should cover at least the following elements.
| Clause | What it must specify |
|---|---|
| Scope of work | Full, room-by-room detail, backed by plans and specs. |
| Materials | Brands, models and grades; who supplies them. |
| Price | Fixed, or hourly with a capped estimate; how unforeseen items are handled. |
| Schedule | Start date, duration, any late penalties. |
| Payments | Staged by progress — never everything up front. |
| Holdback | Percentage withheld until final acceptance and correction of deficiencies. |
| Licence and insurance | RBQ licence number, proof of the contractor's liability insurance. |
| Warranties and termination | Applicable warranties and conditions for ending the contract. |
Staged payments and the final holdback are your two most powerful levers: they keep the balance of power in your hands until the work is done right. A major renovation also has tax implications; some expenses may qualify for a GST/QST rebate on rental-property renovation, provided you have compliant invoices.
What warranties protect a major renovation?
Several layers of protection may apply. It's essential to know which one actually covers you before you sign.
- Legal warranty against latent defects (Civil Code of Quebec): it applies to the work performed. This is your baseline protection against hidden defects.
- Contractor's contractual warranty: the term and scope the contractor offers directly. Get it in writing.
- Guarantee Plan for Residential Buildings (GCR): mandatory for new residential buildings and certain eligible additions, through an accredited contractor. A simple renovation of an existing plex is generally not covered — check your project's eligibility.
- Performance bond or guarantee: negotiate it into the contract for larger projects to protect against a contractor abandoning the job.
Confirm before you sign
Don't assume a guarantee plan "covers everything." Confirm in writing which warranty applies to your specific project, its duration and what it excludes. The GCR mainly governs new construction, not the renovation of an existing building.
Sources: Guarantee Plan for Residential Buildings (GCR) for eligibility; Office de la protection du consommateur for contracts and recourse.
Why avoid under-the-table workers?
"Cash" work — no RBQ licence, no invoice, no reporting — presents itself as a saving. It's often a false economy. If the work is defective or abandoned, you have no structured recourse. If an accident happens on your property, your liability can be engaged. Non-compliant work can jeopardize a future sale, fail an inspection, or trigger a denied insurance claim. And with no compliant invoice, no tax rebate or deduction is available.
The cash-up-front discount almost always hides a transfer of risk — the owner's, not the contractor's. To judge whether work is worth the investment relative to resale price, see our analysis of the impact of deferred maintenance on a plex's sale price.
Common mistakes to avoid
- Starting without a permit "because it's faster": fixing it later costs more than the permit.
- Not verifying the RBQ licence or the subcategories it covers.
- Paying a large cash deposit or the full amount before the work is finished.
- Relying on a verbal quote with no detailed written contract.
- Forgetting the final holdback and losing all leverage to fix deficiencies.
- Not requiring compliant invoices, which blocks tax rebates and warranties.
- Assuming a warranty without having it confirmed in writing.
A well-managed project protects your capital and your plex's resale value. If the work feels too heavy or not worthwhile, a direct sale remains an option: ImmoMulti buys multi-unit properties on the North Shore as-is, with no need to renovate first.
