Owning several parcels: check them together, appeal them separately
Assessments are individual. Reviewing a portfolio at once shows you which one is the outlier.
If you own several parcels, check them together and appeal them separately. Both halves of that matter.
Why check them together
Patterns are only visible across a set. Reviewing parcels as a group surfaces things a single-property review never would:
- One property assessed well above the others per square foot
- An exemption applied to one and not another
- A class code that is inconsistent across similar buildings
- A parcel you had forgotten you owned — a vacant lot, a garage parcel, a strip of land from an old subdivision
That last one is more common than it sounds, particularly where property was inherited or assembled over time. It is assessed and billed whether or not anyone is looking at it.
Why appeal them separately
Each parcel is assessed individually and appealed individually. There is no combined filing, and each needs:
- Its own PIN on its own form
- Its own comparables, from its own neighbourhood
- Its own requested value with its own arithmetic
Comparables do not transfer between parcels. A strong case on one says nothing about another two miles away, and an office will treat them as the separate matters they are.
Prioritising, when there are many
You do not have to appeal everything. Rank by expected value: the size of the gap, times what a reduction is worth.
Base rates matter too. Cook publishes appeal success by township, and it varied four-fold in 2024 — 30.6% in Jefferson against 7.6% in Palatine. A marginal case in a low-rate township is a poor use of an evening; the same case in a high-rate one may not be.
The spreadsheet worth keeping
One row per parcel: PIN, address, township, class, floor area, land and improvement assessed values, assessment per square foot, exemptions applied, last appealed, and reassessment year.
Built once, it takes an hour and answers every year's question in ten minutes — which parcels moved, which are out of line, and which are due for reassessment.
The deadlines are not the same
Appeal windows run by township, staggered across months. Parcels in different townships have different deadlines, and in different counties, entirely different calendars.
Diary each one separately. Assuming a single date across a portfolio is the most common way multi-parcel owners miss filings they intended to make.