Based on 30 historical special-purpose appeals in Proviso Township (2022-2025), TaxRival's data shows a 31% win rate at the Board of Review with an average reduction of 34.4% when successful.
Check Your Property →Hotels, nursing homes, self-storage, banks, and theaters. Proviso Township sits in the South/Southwest Suburban triad of Cook County. Our analysis of historical Board of Review appeal outcomes (2022-2025) shows that special-purpose property owners in Proviso have won reductions on 31% of filings, with an average reduction of 34.4% when the BOR grants relief.
The 95th-percentile reduction is 49% — that's our plausibility ceiling for the algorithm, calibrated specifically to special-purpose appeals in Proviso. Cases above this threshold are exceedingly rare in the historical record, so claims significantly above 49% would be flagged as outliers and reviewed before filing.
The strongest recent Board of Review reductions on special-purpose property appeals in Proviso Township, drawn from BOR decisions in tax years 2022–2024. Pre-appeal AV is the Assessor's value before filing; post-appeal AV is the BOR's final decision. These are real outcomes, not estimates.
| Tax Year | Pre-Appeal AV | Post-Appeal AV | Reduction |
|---|---|---|---|
| 2023 | $374,088 | $181,801 | −51.4% |
| 2023 | $2,600,220 | $1,327,485 | −49% |
| 2024 | $374,089 | $195,347 | −47.8% |
| 2023 | $1,229,398 | $722,042 | −41.3% |
| 2022 | $2,092,474 | $1,359,280 | −35% |
| 2024 | $1,229,398 | $809,218 | −34.2% |
| 2022 | $899,999 | $702,376 | −22% |
| 2023 | $1,536,225 | $1,427,258 | −7.1% |
| 2022 | $261,258 | $254,286 | −2.7% |
| 2022 | $261,251 | $254,278 | −2.7% |
| 2024 | $1,536,226 | $1,536,226 | 0% |
| 2024 | $1,327,485 | $1,327,485 | 0% |
Source: Cook County Assessor's open data portal (appeal_history dataset). Property identifiers are not displayed for privacy; figures are public record.
TaxRival's algorithm uses township-and-class-specific calibration, not a generic countywide average. When we evaluate your special-purpose property in Proviso, we use the 49% cap from this dataset, the 31% historical win rate as a confidence input, and class-specific comparable sales matched to your asset type.
For a deeper look at how Cook County BOR appeals perform across all townships and asset classes, see our 2024 BOR appeal success rates analysis covering all 57,960 commercial and industrial appeals filed last year.
Enter your 14-digit Cook County PIN to see whether your Proviso special-purpose property is over-assessed. Our analysis is free, and if we file an appeal, you only pay 25% of first-year savings. No reduction, no fee.