Your Assessment Is Not Your Home’s Value
January brings the assessment notice and the same question every year. The gap isn’t an error — it’s built into what an assessment is designed to do.
No, and the difference is structural rather than a mistake. City of Calgary assessments use mass appraisal against a valuation date of July 1 of the previous year — so by the time the notice lands in January it is already reflecting a market roughly six months old, and if prices moved in between, the assessment is stale by exactly that much. Mass appraisal also works from property characteristics on file, not from an inspection: it cannot see your renovated kitchen, your dated bathrooms, or the condition of the roof. Assessments exist to distribute property tax fairly across hundreds of thousands of properties, which they do well; pricing an individual home is a different job.
The two structural reasons they differ
- The valuation date is old news. Assessments reflect market conditions as of July 1 of the previous year. Your January notice is describing last summer. In a market that moved either direction in between, the gap is that movement — not an error.
- Mass appraisal can’t come inside. Assessments are produced at scale from characteristics on file — size, age, lot, location. Nobody walked through. A gut renovation and a 1978 original with the same footprint can carry near-identical assessments and sell tens of thousands apart.
Neither is a flaw. Assessment exists to divide the tax burden fairly across the whole city, and for that purpose consistency matters more than per-house precision.
So which number should you use?
For tax fairness — is my assessment in line with similar homes? — the assessment is the right instrument, and the City runs a formal complaint process with a deadline printed on your notice. For pricing a sale, you need current sold comparables, and those aren’t public in Alberta — that’s the actual reason "just check the assessment" persists as advice.
What your home would actually sell for
Send me your address and your assessed value — I’ll come back with what current sold comparables say your home would realistically sell for today, and where the gap comes from. Free, no obligation, and useful even if you’re only checking whether your assessment is fair.
Last updated 2026-08-26 · Written by Mohammad Emon, REALTOR® (SRES®) & Licensed Property Manager, KO Realty · RECA licence LIC-00666633