ImmoMulti — a direct buyer of income properties on the North Shore — regularly sees plex buildings where a unit was added without a permit: a basement turned into a rental, a fourplex where zoning allows only a triplex, an attic converted into a dwelling. On paper, the building generates more income. But at sale, that illegal or non-conforming unit can sink the buyer's financing, alarm the insurer and expose you to a municipal order. This guide, written for the owner-seller, explains the real risks, the crucial difference between "derogatory" and "illegal", and your three options: regularize, invoke acquired rights or sell with full disclosure.
Non-conforming, derogatory or illegal: what's the difference?
"Derogatory" is not synonymous with "illegal" (MAMH). A derogatory use existed legally before a new by-law and may be maintained through acquired rights. An illegal unit was created without a permit or in breach of zoning: it is unprotected, and the city may require its removal.
Confusing these terms is costly for plex sellers. According to Québec's Ministry of Municipal Affairs and Housing (MAMH), a derogatory building or use does not comply with the current zoning by-law but was compliant when it was carried out. It is that time gap that can open the door to acquired rights.
An illegal unit, by contrast, was never compliant: a basement dwelling added without a building permit, a multi-unit building with more units than zoning allows, or a conversion done without any declaration. The legal point is clear: no acquired right arises from construction or use carried out illegally, even if the municipality tolerated the situation for a long time.
Sources: Ministère des Affaires municipales et de l'Habitation — "Zoning by-laws and acquired rights" and Québec.ca — "Zoning by-laws and acquired rights".
Do acquired rights actually protect my extra unit?
This is the first question every owner of a plex with one more unit than expected asks. The answer depends entirely on how the unit came to exist.
According to the MAMH, a building protected by acquired rights keeps those rights even if it is leased or sold to another owner. Good news for a seller — with one condition: the rights must genuinely exist. The protection applies only to legally existing rights. A unit added without a permit creates no right to transfer.
Second trap: the burden of proof always falls on the person claiming an acquired right. It is not up to the city to prove your fourplex is illegal — it is up to you to prove it was compliant and occupied as such before the by-law changed. Without the original permit, older assessment rolls, historical leases or dated photos, that proof is fragile.
"No acquired right can arise from construction, the use of land or a building, or a subdivision carried out illegally."
— Ministère des Affaires municipales et de l'Habitation, urban-planning decision guide
What are the concrete risks when I sell a non-conforming plex?
Three risks dominate: refusal or conditioning of the buyer's financing and insurance, a municipal order to comply or close the unit, and a price reduction — or even a hidden-defect claim if the non-conformity is not disclosed.
1. Financing and insurance. A buyer's lender requires insurance on the income property and assesses the number of units. If the actual unit count exceeds zoning, or the certificate of location notes a derogation, the insurer may decline coverage or the lender may pull financing. A promise to purchase conditional on financing then collapses — and the sale with it.
2. Municipal order. The city may require compliance, impose fines and, in some cases, order the unit closed. If a dwelling is separately declared unfit for habitation by the Administrative Housing Tribunal, the landlord can no longer re-rent it and an evacuation notice may follow — a direct loss of income.
3. Price and liability. An informed buyer factors the cost of regularization and the regulatory risk into the offer: the price drops. And a concealed non-conformity can ground a claim against you.
Caution — silence can backfire
A known but undisclosed non-conformity can be raised by the buyer as a hidden (latent) defect for three years from its discovery. Transparency from the promise to purchase onward is your best legal protection.
Sources: Administrative Housing Tribunal (TAL) — "Unsanitary conditions" and Éducaloi — "Hidden defects in a building".
Option 1 — Regularize the unit before selling
Regularizing means making the unit legal in the municipality's eyes. This path maximizes your plex's value but takes time and money.
In practice, regularization runs through a retroactive permit application, then code-compliance work (egress, ceiling height, soundproofing, alarm systems, ventilation). If zoning outright prohibits the unit count, you must aim for a by-law amendment or minor variance — the outcome of which depends on the municipal council and is never guaranteed.
Often overlooked: renovating a rental dwelling generally requires a contractor holding a Régie du bâtiment du Québec (RBQ) licence, on top of the municipal permit. The fact that a job does not require an RBQ licence does not exempt it from the city's permit. And a declaration of work must be sent to the RBQ, no later than the 20th day of the month following the start of the work, where it applies.
When regularization is worth it
- Zoning already allows the actual number of units;
- Code-compliance work is modest and quantifiable;
- You have time before listing;
- The value difference justifies the investment.
Source: Régie du bâtiment du Québec — "Declaration of work".
Option 2 — Document and invoke acquired rights
If the unit existed legally before a by-law change, it may be protected by acquired rights. Your job as seller is then to build the evidence, since the burden is on you.
Gather the original building or conversion permit, successive assessment rolls showing the unit count, old leases, tax accounts, dated photos and, if possible, a municipal certificate of conformity. A municipal-law professional can then confirm whether the acquired rights actually hold.
This option avoids construction but leaves some uncertainty: a poorly documented acquired right can be challenged by the city on a change of use, a major renovation or an insurance claim. Disclose it clearly to the buyer, with supporting documents.
| Situation | Likely status | What it changes at sale |
|---|---|---|
| Unit compliant when created, before a new by-law | Protected derogatory (acquired rights, if proven) | Sellable; document proof to reassure lender and insurer |
| Basement finished without a permit | Illegal — no acquired right | Regularize or sell "as is" with disclosure |
| More units than zoning allows | Non-conforming; acquired right to prove or absent | Financing-refusal risk; adjusted price |
| Permit issued illegally by the city | No acquired right (MAMH) | Treat as an illegal unit |
Source: Ministère des Affaires municipales et de l'Habitation — acquired rights in urban planning.
Option 3 — Sell with full disclosure, as is
You can sell a plex with a non-conforming unit without regularizing it, provided you disclose everything. According to Éducaloi, what the seller honestly declares can no longer be raised as a hidden defect. Disclosure protects you and lets the buyer adjust the offer and financing with full knowledge.
Every seller of a residential property must complete a seller's declaration and disclose what they know about the building's condition, including a unit added without a permit. It is both a duty and a shield: what is declared can no longer ground a hidden-defect claim.
Selling "as is" on the traditional market remains possible, but a retail buyer will often hit a wall with their lender or insurer. That is why many owners of income properties on the North Shore choose a direct buyer like ImmoMulti: we buy the building in its real condition, non-conforming unit included, without depending on a third party's financing or imposing a regularization timeline.
Sources: Éducaloi — "Steps to take in case of a hidden defect" and OACIQ / Protégez-Vous — "Seller's disclosure obligations". Consult a notary or lawyer for your specific situation.
How to verify whether a unit in your plex is compliant
Before choosing between regularizing, invoking acquired rights or selling "as is", a savvy seller first makes the diagnosis. Many owners of plexes on the North Shore only discover a non-conformity at the point of sale, when the buyer's notary or the lender's appraiser compares the actual unit count with what is officially recognized. Doing this work upstream gives you control: you choose the timing, the message and the strategy, rather than facing a nasty surprise in the middle of a promise to purchase.
The five documents to gather first
A unit's compliance is not inferred from a walkthrough — it is proven by documents. Here is the logical order of verification, from most revealing to most incidental.
- The municipal assessment roll. It states the number of units recognized by the city (for example "3 units"). If your building actually contains four, you already have your first red flag. The roll is public and can be consulted at the municipality or the RCM (MRC).
- The up-to-date certificate of location. Prepared by a land surveyor, it describes the building as it exists and often notes known derogations or encroachments. A certificate referring to a "derogatory use" or a "non-conformity" is a central piece of the file.
- Building and conversion permits. Ask the urban-planning department for the history of permits issued for the address. The absence of a permit for a basement or attic unit is decisive: without an original permit, the acquired-rights argument collapses.
- The applicable zoning by-law. It specifies how many units are allowed in the zone where your building sits. It is what distinguishes a perfectly legal fourplex from an illegal one in a zone limited to triplexes.
- Leases, tax accounts and older rolls. They establish how long the unit has been occupied — key if you later need to prove acquired rights.
Request written confirmation from urban planning
The most effective step is also the simplest: write to your municipality's urban-planning department to request the building's official status. According to the Government of Québec's By-law on permits and certificates in urban planning, issuing permits and certificates falls to each municipality, which keeps the corresponding records. A written reply — even by email — is worth more than a verbal answer at the counter, because it documents your good faith and feeds your seller's declaration.
One caveat, though: asking the question can "wake up" a file. If the unit is clearly illegal and the municipality is unaware, a formal request may trigger an inspection. That is why many sellers first have the situation validated by a municipal-law professional or an experienced building inspector before deciding whether to quietly regularize or sell to a buyer who assumes the risk.
Express self-diagnosis checklist
- Does the assessment roll confirm the actual number of units?
- Is there a permit for each unit, including basement or attic ones?
- Does zoning allow this number of units in your zone?
- Does the certificate of location note a derogation?
- Can you prove how long each unit has been occupied?
If you answer "no" or "I don't know" to any of these, treat compliance as unproven and document the situation before listing.
Source: Government of Québec — "By-law on permits and certificates in urban planning".
Basement and attic: the standards that make a unit illegal
The most common case of a non-conforming unit in a Québec plex is the basement dwelling — sometimes called a "bachelor" or accessory unit — or one fitted into the attic. These spaces were often rented without ever meeting minimum habitability and safety standards. Understanding those standards helps you estimate, numbers in hand, what regularization would cost and why a lender or insurer may hesitate.
Ceiling height
A habitable basement room must offer a clear height of roughly 1.95 m (6 ft 5 in) to be considered livable. The classic trap: after adding an insulated subfloor, furring and a drywall ceiling, a basement that seemed tall enough drops below the threshold. A unit with a ceiling that is too low generally cannot be regularized without excavation — heavy work that radically changes the financial equation.
The egress window
Each basement bedroom must have at least one compliant egress window: if fire blocks the stairway, it is the only way out. Commonly cited benchmarks are an opening area of at least 0.35 m² (about 3.8 sq ft), no dimension smaller than 380 mm (15 in), and, if the window opens into a window well, enough clearance in front of it to allow escape. A basement bedroom without a compliant egress is a frequent reason for insurance refusal and a major safety risk.
Fire separation and alarms
Between two dwellings, an adequate fire separation is required to slow the spread of a fire. Add smoke alarms and, often, carbon-monoxide alarms. Many "homemade" added units have neither a compliant separation, nor adequate ventilation, nor a safe exit — all things an inspector or the city will flag.
| Typical requirement (basement) | Common benchmark | Impact if not met |
|---|---|---|
| Ceiling height | ≈ 1.95 m (6 ft 5 in) | Often unrecoverable without excavation |
| Egress window per bedroom | ≥ 0.35 m², min. 380 mm | Insurance refusal, fire risk |
| Fire separation between units | Required | Possible compliance order |
| Smoke / CO alarms | Required | Fine, unit deemed unfit |
Caution — standards vary from one city to another
The benchmarks above are indicative. Exact requirements depend on the Construction Code, the building type and municipal by-laws, which can vary across the North Shore. Have every value confirmed by the urban-planning department and an RBQ-licensed contractor before undertaking work.
Sources: Régie du bâtiment du Québec — residential occupancies (Safety Code) and municipal fact sheets on habitable basement rooms. Values to be confirmed with your municipality.
Minor variance or rezoning: the regularization path
When zoning does not allow your plex's actual unit count, simply obtaining a retroactive permit is not enough: you first have to remove the regulatory obstacle. Two paths exist, and it is crucial to understand their limits before investing time and money.
The minor variance: useful, but not for everything
A minor variance is an exception procedure through which the municipal council can authorize work or regularize a situation that does not meet all provisions of the zoning or subdivision by-law. Note one decisive point: according to the Government of Québec, a minor variance cannot address uses or land-occupation density. In other words, it can settle a setback, a height or an area, but it generally does not let you take a building from three to four units where density prohibits it. This is a nuance many sellers discover too late.
The procedure itself is framed: the municipality must have a minor-variance by-law and a planning advisory committee (CCU) that gives an opinion on each request. A public notice must be published at least 15 days before the council meeting that will decide, at the applicant's expense. Finally, the council exercises a discretionary power: it may accept, refuse, or grant only part of the requested variance. Nothing is guaranteed.
By-law amendment and specific projects
When it is truly density or use that blocks you, you must aim higher: a zoning by-law amendment or a specific construction, alteration or occupancy project (PPCMOI). These procedures are longer, more uncertain and often subject to public participation, even a referendum process. For an owner in a hurry to sell, this path is rarely realistic within a transaction's timeline.
| Regularization path | What it can fix | What it cannot fix | Indicative time |
|---|---|---|---|
| Retroactive permit + work | Code non-conformity (egress, fire separation) | Zoning itself | Weeks to months |
| Minor variance | Setbacks, heights, areas | Use and density (unit count) | 1 to 3 months |
| Rezoning / PPCMOI | Use and density, case by case | Nothing guaranteed; discretionary | Several months |
Sources: Government of Québec — "By-law on minor variances" and "By-law on specific construction projects".
Why the buyer's financing and insurance stall
A seller often thinks compliance is a matter between them and the city. In reality, on an income property, it is mostly the buyer's lender and insurer that sink transactions. Understanding their logic lets you anticipate — and explains why a direct buyer able to pay cash sidesteps the problem.
The lender looks at the "official" unit count
When a buyer finances a plex, the bank or CMHC calculates the loan based on the recognized number of units and legitimate revenue. If the assessment roll says "3 units" but the seller rents four, the fourth unit's income is not necessarily counted — and worse, the lender may refuse the whole file on discovering the irregularity. The certificate of location, required by the notary, almost always brings the non-conformity into the open.
The insurer may refuse to cover the risky unit
A basement dwelling without a compliant egress, a missing fire separation, a "homemade" electrical connection: all reasons for an insurer to refuse the policy or attach conditions. And without insurance, no mortgage. The chain breaks at its weakest link.
The scenario that sinks one sale in two
Promise to purchase accepted → inspection → the notary orders the certificate of location → a non-conformity appears → the lender pulls financing → the financing condition is not lifted → the sale falls through. The seller loses weeks and the property returns to market "burned".
It is precisely this risk that pushes many owners of income properties on the North Shore to favour a buyer who needs neither bank financing nor conditional insurance coverage to close.
Worked example: regularize, sell as is, or sell to a direct buyer
Nothing beats a concrete case to compare the three options. Take a fictional triplex on the North Shore whose basement was converted into a fourth unit without a permit. The figures below are illustrative — they show the decision mechanics, not a market value. Consult a broker, a chartered appraiser and a tax specialist for your real situation.
The starting point
- Building presented as a "fourplex", but zoned and recognized as a triplex;
- The 4th unit (basement) earns rent, but without a permit, compliant egress or fire separation;
- Value perceived "on 4 units": clearly higher than the value recognized on 3.
| Scenario | What the seller assumes | Timeline | Effect on net price |
|---|---|---|---|
| A — Regularize, then sell | Retroactive permit (often costlier than a normal one), work (egress, fire separation, ventilation), risk that zoning refuses the 4th unit | Long | Potentially the best, if zoning allows the 4th unit — otherwise "wasted" work |
| B — Sell as is on the market | Full disclosure, discount for risk, uncertain buyer financing | Variable, often long | Reduced; risk the sale falls through |
| C — Sell to a direct buyer | Full disclosure; the offer reflects the building's real status | Short (fast offer) | Certain and with no financing condition |
Key cost and tax point: according to several specialized sources, a retroactive permit obtained under the pressure of a resale is often markedly more expensive than a permit requested normally. Add the code-compliance work, and scenario A only makes sense if zoning actually allows the extra unit. Otherwise, you pay for work on a dwelling that will stay illegal.
The right question to ask
- Does zoning truly allow the number of units I rent?
- Do I have the time and budget for work whose outcome depends on the municipal council?
- Is the certainty of an unconditional sale worth more to me than a higher but fragile theoretical price?
Indicative costs and timelines; to be validated with your municipality, a chartered appraiser and a notary. Informational content, not financial advice.
What the municipality — and the TAL — can actually do
Fear of a municipal order is legitimate, but often misunderstood. An owner sometimes imagines "the city will never do anything", other times "it could demolish everything tomorrow morning". The reality is more nuanced, and knowing it helps you assess your non-conforming plex's real risk.
The range of municipal sanctions
According to the Government of Québec, a municipality has several remedies for a breach of urban-planning by-laws. It can require compliance, impose fines, and, in the most serious cases, go to court for a compliance or demolition order. In practice, demolishing an occupied unit is a last resort; the most frequent outcome is an order to regularize or to cease the illegal use.
The distinct role of the Administrative Housing Tribunal
You must distinguish urban planning (the city) from housing law (the TAL). If a dwelling is declared unfit for habitation — for instance because of a health or safety problem — the landlord can no longer rent it, and an evacuation notice may be issued. A non-conforming unit therefore sometimes faces two fronts: an urban-planning risk on the city side and a rental risk on the TAL side. In both cases, the result for the seller is the same: lost income and reduced value.
"The municipality can exercise various remedies to stop a breach of its urban-planning by-laws, including asking a court to order work to be carried out or a structure demolished."
— Government of Québec, urban-planning decision guide (remedies and sanctions)Should you wait for the city to "forget"?
Some owners bet on time, believing that long municipal tolerance creates a right. It does not: the MAMH is clear that no tolerance turns an illegal unit into a protected one. The risk does not disappear; it simply shifts to the buyer — who will have it analysed by their lender, insurer and notary. Betting on forgetfulness means gambling that nobody will look closely; at sale, someone always does.
Source: Government of Québec — "Remedies and sanctions for breaches of urban-planning by-laws" and Administrative Housing Tribunal — "Unsanitary conditions".
The seller's declaration: your best legal shield
Many sellers see the seller's declaration as a risky formality — "why write down in black and white that my unit is illegal?". It is exactly the opposite: filled out properly, it is your best protection against a hidden-defect claim.
A mandatory form since 2012
Since July 1, 2012, the seller's declaration has been mandatory for the sale, through a broker, of a mainly residential property with fewer than five units. The seller details the building's condition and history: year of construction, servitudes, water damage, work done, and any known adverse factor — which includes a unit added without a permit.
The principle: what is declared is no longer "hidden"
The legal logic is simple. A defect is only "hidden" if it was unknown to the buyer at the time of sale. According to Éducaloi, what you disclose honestly can no longer be raised as a hidden defect: the buyer buys with full knowledge. Conversely, a non-conformity you knew about and stayed silent on can ground a claim for three years from its discovery. Silence is not a saving; it is a deferred debt.
How to properly disclose a non-conforming unit
- Describe the unit concerned precisely (e.g. basement dwelling);
- State the lack of permit or the zoning non-conformity, if applicable;
- Attach relevant documents (certificate of location, roll, planning emails);
- Avoid "reassuring" the buyer with claims you cannot prove;
- Have your declaration reviewed by a notary or legal professional.
A counter-intuitive detail: falsely "reassuring" the buyer can turn an apparent defect into a legally hidden one. If you minimize or distort the situation, you lose the protection that honest disclosure would have given you. Transparency is not only ethical — it is strategic.
Sources: OACIQ — "Declarations by the seller of the immovable" form and Éducaloi — "Hidden defects in a building".
Common mistakes sellers of a non-conforming plex make
After seeing many income-property files on the North Shore, certain mistakes recur constantly. Avoiding them can save a sale — or thousands of dollars.
- Confusing "tolerated" with "legal". A unit the city never bothered is not therefore compliant. Tolerance creates no acquired right.
- Assuming acquired rights are automatic. The burden of proof is on you: without an original permit or documentation, the argument collapses at the first serious review.
- Disclosing nothing so as not to "scare off" the buyer. That is the surest way to expose yourself to a hidden-defect claim for three years.
- Regularizing before checking zoning. Paying for a retroactive permit and work for a unit zoning will never allow is money lost.
- Inflating the value "on X units". Presenting a triplex as a fourplex scares off lenders and insurers and weakens any financing-conditional promise to purchase.
- Waiting until the last minute. Discovering the non-conformity mid-transaction leaves few options and erodes bargaining power.
- Choosing "homemade" work. Renovating a rental dwelling generally requires an RBQ-licensed contractor and a municipal permit; DIY compliance recreates a risk.
The costliest mistake
Refusing to face reality. A seller who ignores their building's status is subject to others' decisions — lender, insurer, city. A seller who documents their situation keeps the initiative and chooses the best exit.
Building an airtight acquired-rights file, step by step
If your extra unit may genuinely be protected by acquired rights, the difference between a sale that closes and one that collapses often comes down to the quality of your evidence file. Because the burden of proof is on you, treat this like assembling a legal dossier — not a casual folder of papers. A well-built file reassures the buyer's lender, insurer and notary, and shortens negotiations on your plex.
Step 1 — Establish the "before" state
Acquired rights hinge on one fact: the unit existed legally before the by-law that now prohibits it. So your first job is to date the unit's creation and the by-law change. Request the successive zoning by-laws for your zone from the urban-planning department, and pin down when the restriction took effect. Then gather anything showing the unit existed and was occupied before that date.
Step 2 — Collect the primary documents
Some documents carry far more weight than others. Rank your collection by evidentiary strength:
| Document | What it proves | Evidentiary weight |
|---|---|---|
| Original building / conversion permit | The unit was authorized at creation | Very high |
| Successive assessment rolls | Unit count recognized over time | High |
| Old leases and tax accounts | Continuous occupation of the unit | High |
| Dated photos, utility records | Physical existence at a given date | Medium |
| Municipal certificate of conformity | City's recognition of status | Very high |
Step 3 — Watch for what breaks acquired rights
Acquired rights are not indestructible. They can be lost or challenged if the use is interrupted for a prolonged period, if the unit is enlarged or intensified beyond the protected right, or after a major renovation or an insurance claim that changes the building. Document continuity carefully: a gap in occupation is exactly what a municipality will probe.
Step 4 — Have it validated, then disclose
Once assembled, have the file reviewed by a municipal-law professional who can confirm whether the acquired rights actually hold. Then disclose the analysis and the supporting documents to the buyer in your seller's declaration. A documented, professionally validated acquired right is a selling point; an assumed, undocumented one is a liability waiting to surface.
Turn evidence into a sale asset
- Present the file as an organized package, not loose papers;
- Lead with the strongest documents (original permit, certificate of conformity);
- Explain any occupation gaps proactively;
- Include the professional's written opinion, if you have one;
- Give the buyer's lender what it needs to say "yes" with confidence.
Source: Ministère des Affaires municipales et de l'Habitation — acquired rights in urban planning. Consult a municipal-law professional for your specific file.
Informational content only. Does not constitute legal or tax advice. Zoning, acquired-rights rules and code requirements vary by municipality. Consult a municipal-law professional, notary or building-permit officer for advice specific to your property.