Chicago already
paid for this block.
Chicago already dug the sewer, laid the water main, and paved the street. It plows that street every winter. The only thing that changes is how many households are paying for it.
At zero this is the block as it stands today. Nothing here happens all at once, and no block in Chicago has ever redeveloped that way.
An illustration, not a survey of a real block. Every number comes from six assumptions you can change.
What the city maintains, either way
The street, the plowing, and the alley come out of the city's general fund, which property taxes feed. The water main and sewer do not. Chicago runs water and sewer as separate funds paid for by water bills. Those costs are close to fixed whether the block holds 24 households or 96, so more households on the same pipe means a smaller share of that bill for each one.
Change the assumptionsShowHide
Every number in the drawing above comes from these six. Nothing is hidden. If you think one of them is wrong, put in your own and see what happens.
The two value fields move independently on purpose. A new four-flat is worth roughly what it costs to build, and that figure barely changes across the city. What a house is worth changes enormously. Set both to match the block you have in mind.
Nearly the same lot.
| 2023 tax year | Single family home | Four unit building |
|---|---|---|
| Lot size | 2,600 sq ft | 2,509 sq ft |
| Estimated value | $538,540 | $1,212,400 |
| Property tax bill | $10,138 | $24,966 |
| Tax per square foot of land | $3.90 | $9.95 |
The two lots are almost the same size, within about a hundred square feet. The four unit building pays about two and a half times the tax.
This is not a rare block.
Nobody is proposing to rebuild all of them. But every one of those lots sits on a street Chicago already pays to plow and repave. Each one that adds a unit adds someone to help carry that bill.
Four things worth clarifyingShowHide
A bigger tax base is not automatically more city revenue. The City of Chicago is a home rule government and is exempt from the state property tax cap. If the city holds its levy flat, new construction lowers the rate for everyone instead of raising revenue. Chicago Public Schools is capped, and new construction is a written exception to that cap, so schools do capture it.
Four-flats don't pencil everywhere. A new four-flat is worth roughly what it costs to build, and in much of Chicago that is more than the finished building would sell for. Blocks like this get rebuilt where the math works, and the math does not work everywhere. Allowing the building is only half the job. What it costs to put up has to come down too, and Chicago showed it can move on that when it ended parking mandates near transit in 2025. Permitting timelines, stair and exit rules, and minimum lot area per unit are still on the list.
This page only counts one side of the ledger. More households mean more garbage pickup, more street cleaning, and more police calls. None of that is netted out here, and a full accounting would have to do it.
A TIF district would change the answer. If this block sits inside a tax increment financing district, most of the new value goes to the TIF fund rather than to the city, the schools, or the parks, and it stays there until the district expires. A large share of Chicago is inside one. Check yours before assuming the money lands where this page says it does.
Go look at your own block.
Our Value Per Acre Map shows what every parcel in Chicago pays against the land it sits on. Find your street and see where it lands.
Open the mapAsk your alder what it would take to allow four-flats by right on a block like this one. The answer tells you where the real obstacle sits, and it is usually not the money.
Find your alderTwo figures on this page are still our own estimates. If you work with assessment data, construction costs, or city finance, we would rather you told us we were wrong than let it go out unchallenged.
Get in touchSources and notesShowHide
Illustrative example from Strong Towns Chicago. Chicago's grid runs 660 feet from cross street to cross street, measured centerline to centerline. Subtract the right-of-way of one cross street and about 594 feet of block face is left for lots, which is why 24 lots at 25 feet is a reasonable stand-in for a real block. Assessment level 10% for Class 2 residential. Detached single-family homes are 25.6% of Chicago's 1,277,054 housing units per the American Community Survey, which is where both the 327,000 count and the one in four share come from. Equalizer and composite rate should be checked against the current Cook County Clerk tax rate report. The two buildings shown are real Chicago properties; values and tax bills are 2023 tax year figures from Cook County Assessor records and should be re-verified, with addresses or PINs published, before this page is cited. Water and sewer operate as separate enterprise funds supported by user charges, so the tax figures on this page cover the street and general fund services only.