What the Calgary complaint records actually show
Short answer. 70% of 2025 matched residential complaints to Calgary's Assessment Review Board ended in a reduction across 1,685 records, while only about 1 in 200 homeowners filed at all.
The headline figure
Matching Assessment Review Board decisions against the assessment roll for the same properties gives 1,685 usable 2025 residential complaints. 70% of them ended with a reduced assessment.
Set against that, about 1 in 200 Calgary homeowners file in a given year. The gap between those two numbers is the only genuinely actionable finding in this project, and it does not depend on our engine working at all.
Our own scoring does not predict who wins
The obvious product is a tool that tells you whether you will win. We built the scoring, then tested it against the real outcomes. Homes it flagged as a strong case won about as often as the homes it refused — p = 0.61. The verdict carries no information about the outcome.
We are publishing that because it is true and because it survived three separate corrections to the analysis, two of which reversed an earlier conclusion of our own. The working file, including what was wrong the first two times, is in the repository.
One thing that did show a signal
Using building-permit floor area — which the open roll does not carry — and comparing assessed dollars per square foot against similarly sized homes, one band separated: homes assessed 0 to 8% above the median $/sqft for their size won 82% of the time against 71% for everyone else (n = 484, p = 0.0096).
Treat that as promising rather than established. It rests on a single year, and the band was identified in the same data it is measured on. The 2025 roll is the only one where the disputed values are populated, so the replication year does not exist yet.
Sources and method
- City of Calgary open residential assessment roll.
- Calgary Assessment Review Board decision records, joined to the roll on the disputed property.
- 2025 records only. The 2024 roll snapshot predates the amendment cycle, so reductions are invisible in it; pooling the two years blended a blind year with a sighted one and produced two earlier, wrong conclusions.
- Every figure on this site is quoted with its sample size, and each one traces to a script that reproduces it.
Questions
- What percentage of Calgary property assessment appeals succeed?
- 70% of 2025 matched residential complaints ended in a reduction, across 1,685 Assessment Review Board records.
- How many Calgary homeowners appeal their assessment?
- about 1 in 200. The low participation rate, rather than any prediction about individual cases, is the finding that matters.
- Where does FairAssess get its data?
- The City of Calgary's open residential assessment roll and Calgary Assessment Review Board decision records. Both are public.
Check your own address
The lookup compares your assessed value against genuinely comparable homes in your community — and tells you when the public data cannot settle it.
Last reviewed 2026-09-22. Sources and method: what the complaint records show.