Chicago legalized accessory dwelling units in five pilot areas starting May 1, 2021. In the five-plus years since, the city has issued 201 building permits that we can tie to the program — fewer than one a week, citywide.
856 permits screened, 201 counted as ADU permits · May 2021 through late July 2026An accessory dwelling unit, or ADU, is an additional home added to a property that already holds at least one: the ordinance recognizes two forms, a conversion unit carved out of an existing building (usually a basement or attic) and a coach house, a separate small building at the rear of the lot, often above a garage. Chicago banned new units of both kinds for decades; a 2020 ordinance re-legalized them, starting May 1, 2021, in five pilot areas on the North, Northwest, West, South and Southeast Sides — the city’s program page has the map. This page counts what that pilot produced, in the most direct public record available: building permits. A permit is permission to build, not proof a unit was finished and occupied, and the count below is of permits.
Fewer than one permit a week
The pilot’s pace has been flat: 45 permits in 2022, 40 in 2023, 33 in 2024, 41 in 2025. Of the 201 permits, 134 are conversions and 67 are new coach houses. For scale: our permits reporting counted 698 new-construction permits citywide in the first half of 2026 alone, and our flats reporting found the city’s stock of two-to-six-flats shrinking by roughly a building a day. Whatever the ADU pilot has been, it has not been a volume housing program.
Two-thirds of the permits sit in five North Side areas
- Logan Square31
- Lincoln Square26
- Lake View26
- West Town24
- North Center24
The five areas above hold 131 of the 201 permits — 65 percent — and all five sit in or near the North and Northwest pilot zones. The South and Southeast pilot zones barely register in the permit file. We report that as geography, not as a verdict on demand — a permit requires an owner who can finance construction, and this file records outcomes, not applications or intentions.
What we counted, and what we excluded
| What the screen found | Permits | Counted? |
|---|---|---|
| Conversion-unit permits (program or unit-adding language) | 134 | Yes |
| New coach-house permits | 67 | Yes |
| Ambiguous: mentions a coach house, no program or unit-adding language (mostly electrical and meter work) | 206 | No — disclosed here |
| Repairs to existing coach houses (roofs, porches, siding) | 277 | No |
| Wrecking, demolition and sign permits | 83 | No |
| De-conversions (unit removals) | 20 | No |
| False matches (‘ADU’ inside another word, e.g. graduation-event permits) | 69 | No |
Chicago’s permit file has no ADU checkbox, so any count is a classification, and ours is deliberately conservative: the 201 counted permits either name the ADU program or ordinance in their descriptions or plainly add a dwelling unit. The 206 ambiguous permits — work at properties with coach houses, without language saying a unit was created — are not added to the count. The true program total could differ from ours in either direction: higher if some ambiguous permits belong, lower if any counted description overstates the work behind it.
The expansion this count is the baseline for
On September 25, 2025, the City Council voted 46–0 to extend the program beyond the pilot areas — while giving alderpeople power to restrict ADUs in the newly eligible areas, a design Illinois Answers examined when it passed. The expanded program is now in effect: Block Club reported it live on April 1, 2026, and the city’s program page carries the wider eligibility rules. A federal layer arrived the same season: the housing law we scored against Chicago’s records includes a provision opening FHA-insured financing for ADU construction, per the Bipartisan Policy Center’s explainer of the law. The 2026 column above — 27 permits by late July, with the expansion live since April — is the earliest measure of whether any of this changes the pace. Five years of pilot produced fewer than one permit a week; we will re-run this count when 2026 closes.
How we counted
- Source: the city’s building permits file (ydr8-5enu), permits issued May 1, 2021 or later whose descriptions mention an ADU, additional or accessory dwelling unit, or coach house — 856 permits, each read and classified. Retrieved July 27, 2026.
- The word-boundary trap: ‘ADU’ appears inside ordinary words — permits for university graduation ceremonies matched a naive search. We match ‘ADU’ only as a whole word; the 69 false matches are in the table above.
- Counted: a permit whose description references the ADU program or ordinance, or plainly adds a dwelling unit (a new coach house, or a conversion raising the unit count). One permit, one count; permits are not completed units, and this page makes no claim about how many counted permits became occupied homes.
- Not counted: repairs to coach houses that existed before the ordinance, demolitions, de-conversions, and ambiguous permits without unit-adding language. Community-area figures place each permit by its coordinates within Chicago’s 77 official community areas; every one of the 201 counted permits could be placed.
- As of: the permit file is live and gains late-entered rows over time, so a later rerun may differ; figures are as of July 27, 2026. Program details are from the city’s ADU page and the September 2025 ordinance coverage linked above.
Computed by KCM Desk from Chicago building-permit records, May 2021 through July 27, 2026; published July 27, 2026. If you spot an error, corrections come first.