Same land.
Different bill.
Two lots on the same block face. Same street, same sidewalk, same bus stop, same water main underneath. One holds a three story building. The other holds asphalt. Their tax bills are nowhere close. Drag the slider to see what happens if Chicago taxed the land instead of what got built on it.
The city collects the same amount of money at every point on this slider. Illinois property taxes work backward from a fixed dollar levy, so shifting weight from buildings to land changes who pays without changing the total.
One number decides who pays more.
About 27 cents of every dollar of taxable value in Chicago is land. The rest is the buildings sitting on it.
Under a land tax, any property that is more than 27 percent land pays more than it does today. Any property that is less than 27 percent land pays less. That is the entire mechanism.
This parking lot is 96 percent land. The building next door is 20 percent land. Neither one owns more dirt than the other.
Change the numbers
Every figure on this page comes from the fields below. Nothing is hidden. If you think one of them is wrong, put in your own and see what it does.
Both lots use the same assessment level because they sit in the same property class. That is deliberate. If one were assessed at ten percent and the other at twenty five, the comparison would be measuring classification rather than land.
Land value and building value are the two figures the Cook County Assessor already publishes separately for every parcel in the county. Most cities do not break them out at all, which is why this analysis is possible in Chicago and difficult almost everywhere else.
Four things this page is not claiming
A tool that only makes its own case is not worth much. Here is where the argument gets harder.
Illinois probably cannot do this without amending its constitution. Article IX requires real property to be taxed uniformly by valuation. Counties over 200,000 people may sort property into classes, which is how Cook County already taxes a store differently than a house. Taxing the land under a building at a different rate than the building itself is a separate question, and the honest answer is that it would take Springfield and very likely a constitutional amendment. This page describes how the system we have behaves. It is not a bill anyone is filing next session.
A land tax is only as good as land assessment. Cook County land values are produced by formula, and in some neighborhoods they have not been revisited in a long time. If the land number is wrong, everything built on top of it is wrong too. Any serious version of this proposal starts with an audit of land assessment quality, not with a rate.
Not every parking lot is the villain and not every building is the winner. A modest house on a full lot in a neighborhood where houses are cheap can have a high land share and would pay more. Vacant land on the South and West Sides is worth so little that a land tax barely changes the math on holding it. Before anyone proposes this seriously, someone has to run every parcel in the city and publish who pays more.
The defaults here are illustrative. The two lots are a realistic pairing rather than two specific addresses, and the equalizer, composite rate, and citywide land share are stated so you can check them. Swap in a block you know. The mechanism is what this page is trying to show, and the mechanism does not depend on the defaults.
What we build gets taxed. What we sit on does not.
Strong Towns Chicago is a volunteer group making the case for safer streets, abundant housing, and a city that can afford what it already owns. We build tools like this one because the numbers are more convincing than the slogans.