In Quebec, every property has two very distinct values: the municipal assessment recorded on the property assessment roll, and the actual market value. These two numbers serve completely different purposes, and confusing them can lead to costly mistakes when selling or buying real estate.
In 2026, with Quebec’s real estate market having experienced sustained growth for several years, the gap between these two values has never been wider. In certain neighbourhoods of Montreal, Laval, or the South Shore, a house assessed at $350,000 on the roll can easily sell for $475,000 to $525,000.
This article explains in detail why this gap exists, how it affects your property taxes, and most importantly why you should never rely on the municipal assessment to set your sale price.
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Estimate my property📖 Definitions: Municipal Assessment and Market Value
🏛️ Municipal Assessment
Estimated by the municipality
Used to calculate property taxes
Updated every 3 years
Based on a past reference date
💰 Market Value
Determined by the market
Price a buyer would pay today
Fluctuates in real time
Based on recent comparable sales
The municipal assessment is an administrative tool designed to distribute the tax burden fairly among property owners in a municipality. Market value, on the other hand, reflects the real-world reality at a specific moment: supply and demand, property condition, interest rates, and economic conditions.
💡 In a nutshell: the municipal assessment is a photo taken in the past. Market value is a real-time portrait of your property.
📋 How the Assessment Roll Is Calculated
In Quebec, the property assessment roll follows a rigorous process governed by the Act respecting municipal taxation. Here are the key steps:
1. 📅 Reference date — The assessor analyzes sales as of July 1st, 18 months before the new roll takes effect
2. 🔄 Triennial cycle — The roll is updated every 3 years. Montreal’s 2025–2026–2027 roll is based on July 1, 2023 data
3. 🔍 Sales analysis — The assessor compares recent transactions in the area to establish each property’s value
4. 🏠 Adjustments — Corrections are applied for square footage, age, renovations, lot size, and location
5. 📢 Roll deposit — The roll is filed and property owners have 60 days to contest their assessment
⚠️ Critical point: if your city’s current roll is based on July 1, 2023, your assessment reflects prices from nearly 3 years ago. All appreciation since then is not accounted for.
📈 Why the Gap Reaches 20–40% in 2026
Several factors explain the historic gap observed in 2026 between municipal assessments and actual market values:
18 months
Delay between reference date and roll start
3 years
Duration of the assessment cycle
+25–40%
Cumulative price increase since 2023
The structural lag: even in a stable market, the 18-month delay between the reference date and the effective date creates a disconnect. By the end of the triennial cycle (year 3 of the roll), the gap can represent nearly 4.5 years of unaccounted appreciation.
Post-pandemic acceleration: Quebec’s market has experienced exceptional growth since 2021. Median prices rose 30 to 50% in many regions. This rapid rise dramatically amplifies the gap between the assessment and reality.
Undeclared renovations: if you renovated your kitchen, bathrooms, or finished your basement without a permit, the municipal assessor does not account for it. Market value, however, reflects these improvements immediately.
💵 Impact on Your Property Taxes
Your property taxes are calculated using this simple formula:
Taxes = Municipal Assessment × Tax Rate
When a new roll takes effect and assessments increase across the board, the municipality typically adjusts its tax rate downward to avoid a sudden spike in revenue. However, if your property increased more than the area average, your taxes will rise more than your neighbours’.
Before the new roll
$350,000 × 0.8%
= $2,800/year
After the new roll
$450,000 × 0.65%
= $2,925/year
💡 Good to know: even if the tax rate decreases, an assessment increase above the area average will result in a net tax increase for you. This is the principle of tax equity.
🚨 Never Set Your Sale Price Based on the Assessment
This is the most common and costly mistake sellers make in Quebec. Using the municipal assessment as a basis for your asking price is essentially selling your property at a discount.
❌ What NOT to do
“My municipal assessment is $380,000, so I’ll list my house at $395,000.”
Result: you potentially leave $80,000 to $130,000 on the table.
✅ What you SHOULD do
Base your price on recent comparable sales (last 3–6 months) in your area
Use an estimation tool based on real market data
Consult a real estate broker who knows your neighbourhood
The same logic applies to buyers: don’t think a property is “overpriced” because its asking price exceeds the municipal assessment. In the current market, that’s the norm.
🏠 Concrete Examples in Quebec in 2026
Here are realistic examples illustrating the gap between municipal assessment and sale price across different regions:
🏙️ Single-family home — Rosemont, Montreal
Municipal assessment
$385,000
Actual sale price
$545,000
Gap
+41.6%
🏢 Condo — Griffintown, Montreal
Municipal assessment
$310,000
Actual sale price
$395,000
Gap
+27.4%
🏡 Bungalow — Laval (Sainte-Rose)
Municipal assessment
$350,000
Actual sale price
$500,000
Gap
+42.9%
🏘️ Duplex — Villeray, Montreal
Municipal assessment
$480,000
Actual sale price
$640,000
Gap
+33.3%
⚠️ Note: these gaps vary by neighbourhood, property type, and where you are in the assessment cycle. Less sought-after areas may show a smaller gap (10–15%), while high-demand neighbourhoods regularly exceed 40%.
❓ FAQ — 5 Common Questions
What is the difference between municipal assessment and market value?
The municipal assessment is set by the municipality to calculate your property taxes. It is based on a past reference date and updated every 3 years. Market value is the price a buyer would pay today, based on real-time supply and demand. In 2026, the gap can reach 20 to 40%.
Why is the municipal assessment often lower than the sale price?
The assessment roll is based on a reference date that precedes its effective date by 18 months. With the triennial cycle, values can lag 3 to 4.5 years behind the market. In a rising market, the assessment is structurally behind actual prices.
Should I set my sale price based on the municipal assessment?
No. In 2026, a house assessed at $350,000 can sell for $475,000 to $525,000. Setting your price based on the municipal assessment means potentially leaving over $100,000 on the table. Use recent comparable sales instead.
How is the municipal assessment calculated in Quebec?
The municipal assessor analyzes recent sales in the area at a specific reference date (usually July 1st, 18 months before the roll takes effect). Adjustments are then made for building characteristics, lot size, and location.
Does the municipal assessment affect my property tax amount?
Yes, directly. Your taxes = assessment × tax rate. However, when the roll is updated, the municipality often lowers the rate. Your bill will increase mainly if your property gained more value than the area average.
Discover your property’s true value
Don’t rely on the municipal assessment. Get an estimate based on real sales in your area.
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