What evidence a board actually accepts
Public records beat opinions. Four good comparables beat twenty weak ones.
Boards see a great deal of evidence that cannot help them. Here is what can.
Strong
- Comparable assessments from county records, with PINs, addresses and the characteristics that make them comparable. This is the backbone of a uniformity case.
- Recent arm's-length sales of similar property nearby, ideally within a year of the valuation date.
- A recent purchase of the subject itself at arm's length — often the single most persuasive item there is.
- Documented factual errors: a survey, a plan, photographs, a contractor's letter.
- A licensed appraisal as of the correct valuation date.
Weak or useless
- Zestimates and other automated site values. Not accepted as evidence of value.
- What you paid in taxes last year, or the increase. Not the question.
- Listings and asking prices. An asking price is not a sale.
- Foreclosures and family transfers, unless the argument is specifically about distressed markets.
- General statements that taxes are too high.
How much
Three to five tight comparables. A long list invites the assessor to attack the weakest one and treat it as representative.
This is general information about how Illinois assessments and appeals work. It is not
legal advice, not an appraisal, and not a prediction about your case. Deadlines and rules differ by
county — check yours with your Board of Review.