Does RS-1 allow a two-flat?

No. RS-1 permits detached single-family homes only. A two-flat needs RS-3 (on a ≥5,000 sq ft lot) or an RT/RM district.

How many units can I build on a standard lot in RS-1?

A standard 25 × 125 ft Chicago lot (3,125 sq ft) divided by the 6,250 sq ft lot-area-per-unit standard permits 0 units by right. Transit-served lots may qualify for Connected Communities density bonuses.

How tall can I build in RS-1?

30 feet (§17-2-0311-A). Taller buildings need a variation, a planned development, or — on transit-served B-3/C-3 lots — the Connected Communities height bonus.

Can I add a coach house or ADU in RS-1?

Only if the lot sits inside one of the ten designated ADU-Allowed RS Areas (§17-7-0570): the §17-2-0207 use table permits conversion units and coach houses in RS districts by right only within those areas, and several areas add owner-occupancy requirements and per-block annual limits (§17-7-0573 — one pre-certification per block face per year in RS-1 where the annual limit applies). Outside an ADU area, not allowed. See our ADU & coach house guide.

Do parking requirements in RS-1 change near transit?

Yes. The base requirement is 2 spaces per unit, but under the Connected Communities ordinance (§17-10-0102-B) lots within ½ mile of a CTA or Metra rail station — or ¼ mile of a designated bus corridor — can reduce residential parking minimums, up to 100% by right for CTA-rail- and bus-served lots outside downtown districts.

Chicago zoning district · Residential Single-Unit

RS-1 zoning in Chicago: what you can build

RS-1 (Residential Single-Unit (Detached) 1) is one of Chicago’s detached-house districts: it allows detached single-family homes, with a maximum floor area ratio (FAR) of 0.5, a height limit of 30 feet, 6,250 square feet of lot area required per dwelling unit. It is a single-family-only district: no two-flats or multi-unit buildings by right.

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 →

Where RS-1 is mapped

The interactive map needs JavaScript. See the official City of Chicago zoning map instead, or browse every district as text below.

Planned Manufacturing (PMD)
Parks & Open Space (POS)
Planned Development (PD)
Downtown (DC/DR/DS/DX)
Residential (RS/RT/RM)
Business (B)
Commercial (C)
Manufacturing (M)
Transportation (T)
Other / unclassified

Zoning district boundaries: City of Chicago Data Portal. Basemap: © OpenFreeMap © OpenMapTiles © OpenStreetMap contributors.

RS-1 bulk & density standards

RS-1 — Residential Single-Unit (Detached) 1 · Municipal Code of Chicago, Title 17
Maximum floor area ratio (FAR)	0.5 verified §17-2-0304-A, Municipal Code of Chicago
Maximum building height	30 ft verified §17-2-0311-A, Municipal Code of Chicago
Minimum lot area	6,250 sq ft verified §17-2-0301-A, Municipal Code of Chicago
Lot area per unit (density)	6,250 sq ft / unit verified ≈ 7 units per acre §17-2-0303-A, Municipal Code of Chicago
Setbacks (front / side / rear)	20 / 4.9 / 29.9 ft approximation Chicago setbacks are contextual formulas (averages of neighboring lots, % of lot width/depth). These are working scalars — confirm per lot. §17-2-0305..0307, Municipal Code of Chicago
Residential parking	2 spaces / unit approximation Before TOD / Connected Communities reductions. §17-10-0207, Municipal Code of Chicago
Maximum lot coverage	30% approximation

Verified figures match the ordinance table verbatim at the cited section. Approximation flags contextual formulas (setbacks that depend on neighboring lots, use-group-dependent parking) reduced to a working scalar — the ordinance formula governs.

Permitted uses

RS-1 allows detached single-family homes.

detached single-family homes

Transit changes these numbers

Under the Connected Communities ordinance (§17-10-0102-B), transit-served lots can cut residential parking minimums — up to 100% by right within ½ mile of a CTA rail station or ¼ mile of a designated bus corridor (outside downtown districts), and up to 50% near Metra. Density and height bonuses, however, are reserved for -3 suffix B and C districts — a residential district like RS-1 keeps its base bulk standards. Full Connected Communities guide →

RS-1 — common questions

Does RS-1 allow a two-flat?: No. RS-1 permits detached single-family homes only. A two-flat needs RS-3 (on a ≥5,000 sq ft lot) or an RT/RM district.
How many units can I build on a standard lot in RS-1?: A standard 25 × 125 ft Chicago lot (3,125 sq ft) divided by the 6,250 sq ft lot-area-per-unit standard permits 0 units by right. Transit-served lots may qualify for Connected Communities density bonuses.
How tall can I build in RS-1?: 30 feet (§17-2-0311-A). Taller buildings need a variation, a planned development, or — on transit-served B-3/C-3 lots — the Connected Communities height bonus.
Can I add a coach house or ADU in RS-1?: Only if the lot sits inside one of the ten designated ADU-Allowed RS Areas (§17-7-0570): the §17-2-0207 use table permits conversion units and coach houses in RS districts by right only within those areas, and several areas add owner-occupancy requirements and per-block annual limits (§17-7-0573 — one pre-certification per block face per year in RS-1 where the annual limit applies). Outside an ADU area, not allowed. See our ADU & coach house guide.
Do parking requirements in RS-1 change near transit?: Yes. The base requirement is 2 spaces per unit, but under the Connected Communities ordinance (§17-10-0102-B) lots within ½ mile of a CTA or Metra rail station — or ¼ mile of a designated bus corridor — can reduce residential parking minimums, up to 100% by right for CTA-rail- and bus-served lots outside downtown districts.

Compare RS-1

RS-1 vs RS-2