Owner · Valuation
The two most dangerous sentences in a transaction are symmetrical: the buyer's 'it is listed way above the assessment, it is too expensive' and the seller's 'I want at least the assessment plus 30% like the neighbour'. Both reason on an outdated fiscal value.
The municipal assessment is a fiscal value: it serves to distribute the tax burden among a municipality's owners, not to set sale prices. It is established by mass appraisal, filed in a roll valid for three years, and frozen at an earlier reference date: the 2026-2028 roll reflects market conditions as of July 1, 2024. Nobody visited your house, the value is at least 18 months old when the roll takes effect and almost four and a half years old in its last year, and it is a statistical average, reliable at the scale of a neighbourhood and imprecise at the scale of an address. Each year the Ministry of Municipal Affairs and Housing publishes a comparative factor by municipality: estimated market value equals municipal assessment times the comparative factor. For listing a property, only a comparative market analysis based on closed sales does the job.
Three practical consequences. One: nobody visited your house; your kitchen renovation, your redone basement or your new roof are probably not in the calculation, nor is real wear. Two: the value is at least 18 months old when the roll comes into force, and almost four and a half years old in its last year. Three: it is a statistical average, reliable at the scale of a neighbourhood, imprecise at the scale of an address. It does its fiscal job very well; it never claimed to do the job of a chartered appraiser or a market analysis.
In a rising market, market value mechanically exceeds the municipal assessment, simply because the assessment photographs the market of a year and a half ago or more. The gap varies by sector and year; it can reach tens of percent at the end of a roll after a few years of increases. A large gap is therefore neither an anomaly nor a negotiating argument: it is the arithmetic consequence of the time lag. Lenders know it very well: to approve your mortgage, the bank mandates its own appraiser or analyses the current market, never the tax bill.
Each year, the Ministry of Municipal Affairs and Housing (MAMH) publishes a comparative factor by municipality. The official formula: estimated market value = municipal assessment × comparative factor. A factor of 1.00 means the roll was just filed and still matches the market; a factor of 1.15 means the market has risen about 15% since the roll's reference date.
| Tool | What it gives | Its limits |
|---|---|---|
| Municipal assessment | Fiscal value as of July 1, 2024 (2026-2028 roll) | Frozen, mass appraisal, no visit |
| Assessment × comparative factor | Order of magnitude of market value | Municipal average, ignores your street and renovations |
| Comparative analysis (broker) | Price range based on recent comparable sales | Quality depends on the choice of comparables |
| Chartered appraiser | Certified market value of a precise address | Paid; used for disputes, estates, buyouts |
The comparative factor is perfect for a rough estimate, notably in an estate or a share buyout where a neutral starting point is needed. But for listing, it remains an average: two houses identical on the roll can sell $60,000 apart depending on the street, the condition and the presentation.
Your tax bill = assessment × tax rate. When a new roll pushes all assessments up, the municipality generally lowers its rate to collect similar revenue. What determines whether your bill rises is your increase relative to the city's average: above the average, your share rises; below it, it can fall even if your assessment went up. If the city's average roll rises 30% and your assessment 20%, your relative burden decreases. That is also why a low municipal assessment is good news as long as you do not sell: you pay less tax, and the sale price will be decided on the real market anyway. Your future buyer's welcome tax, however, is calculated on the higher of the price paid or the standardized assessment: see our welcome tax guide.
After a new three-year roll is filed, any owner may file a request for review, generally before May 1 following the roll's coming into force, for a modest fee. You must show that the value entered does not match the real value at the reference date (July 1, 2024 for a 2026-2028 roll): comparable sales from that period, errors on the file (area, number of rooms), deficient condition of the property. Worth it if the file contains factual errors (non-existent garage, inflated area) or if comparable sales from the reference period support a clearly lower value. Not worth it if the gap simply comes from the market rising since: the roll measures July 2024, not today. The false good idea: requesting a higher assessment to "justify" a higher sale price. Buyers and their brokers price on comparables, not on the roll; you would only get higher taxes.
The listing price is set with a comparative market analysis: closed sales of the last 3 to 6 months for similar properties in your sector, adjusted for the differences. Neither the municipal assessment, nor the asking price of neighbours still for sale, nor the amount you need for your next project enters that calculation. See how much is my house worth.
No. It is a fiscal value established by mass appraisal at a past reference date (July 1, 2024 for the 2026-2028 roll). Market value comes from recent closed comparable sales.
Multiply the assessment by the comparative factor published each year by the MAMH for your municipality. It gives an order of magnitude, not a listing price.
Yes, after a new roll is filed, generally before May 1 following its coming into force, by showing that the value does not match the real value at the reference date. Market increases since that date are not grounds for review.
Also available in French: version française de ce guide.
Published September 1, 2026 by the Loaa & Manseur team, the number 1 team at RE/MAX Platine in 2024 and 2025, 6th RE/MAX team in Quebec, 15th in Canada and in the global top 50 according to the official RE/MAX ranking. Tell us about your project.
Équipe no 1 de RE/MAX Platine en 2024 et en 2025, 6e au Québec, 15e au Canada et dans le top 50 mondial au classement officiel RE/MAX. Réponse en moins de 24 heures, sept jours sur sept.