Chicago zoning comparison · where FAR nearly doubles
RM-5.5 vs RM-6: which lets you build more?
RM-6 carries the larger envelope — FAR 4.4 vs 2.5; on a standard 25 × 125 ft Chicago lot, RM-6 permits 10 units by right against 7; the height limits are 79 ft vs 60 ft.
Figures originally read from a Title 17 excerpt in a third-party zoning report dated 18 September 2024. On 24 August 2026 the bulk standards — floor area ratio, lot area per unit, building height and minimum lot area — were re-checked against the current adopted edition 2026-S-73 and found unchanged. Setbacks and parking ratios were not part of that pass and still rest on the 2024 reading. Data snapshot generated 2026-08-24. How this data is produced and checked →
Side by side
| RM-5.5 Residential Multi-Unit 5.5 | RM-6 Residential Multi-Unit 6 | |
|---|---|---|
| Max FAR | 2.5 | 4.4 |
| Max height | 60 ft | 79 ft |
| Lot area per unit | 400 sf | 300 sf |
| Units on a standard 25×125 ft lot | 7 | 10 |
| Min lot area | 1,650 sf | 1,650 sf |
| Residential parking / unit | 1 | 1 |
| Max lot coverage | 70% | 75% |
| Permitted uses | multi-unit residential | multi-unit residential and mid-rise apartments |
| Connected Communities bulk bonus tier | No | No |
Green marks the more permissive value. Setbacks are contextual in both districts and omitted here — see the district pages for the working scalars and the governing formulas.