Overview
Worth knowing
- Article-based structure: zoning ordinance organized by articles rather than sequential chapters, creating complex cross-referencing
- 30+ TIF districts overlay the city, providing financial incentives but not modifying base zoning dimensional standards
- HPC holds Certified Local Government (CLG) status from SHPO for historic preservation review authority
+ 7 more in Quirks & notes
Districts
com 3res_sf 2res_mf 2ind 2mu 1
| Code | Name | Category | Min lot | Height | Coverage | FAR | Du/ac | Parking | Setbacks F/S/R |
|---|---|---|---|---|---|---|---|---|---|
| R-1 | Single-Family Residential | res_sf | — | — | — | — | — | — | 30 / 6 / 30 |
| R-2 | Two-Family Residential | res_sf | — | — | — | — | — | — | — / — / — |
| R-3 | Multi-Family Residential Low | res_mf | — | — | — | — | — | — | — / — / — |
| R-4 | Multi-Family Residential High | res_mf | — | — | — | — | — | — | — / — / — |
| C-1 | Neighborhood Commercial | com | — | — | — | — | — | — | — / — / — |
| C-2 | Community Commercial | com | — | — | — | — | — | — | — / — / — |
| C-3 | General Commercial | com | — | — | — | — | — | — | — / — / — |
| C-4/UMU | Urban Mixed Use | mu | — | — | — | — | — | — | — / — / — |
| M-1 | Light Industrial | ind | — | — | — | — | — | — | — / — / — |
| M-2 | Heavy Industrial | ind | — | — | — | — | — | — | — / — / — |
Confidence: confirmed partial under review not found
Overlays
HPO
Historic Preservation Overlay
HPDesignated historic districts and landmarks; CLG status
| review | Certificate of Appropriateness required |
|---|---|
| scope | Exterior alterations, new construction, demolition |
PUD
Planned Unit Development Overlay
PDPUD applications; ISR-based trigger at >= 0.60
| trigger_isr | 0.6 |
|---|---|
| effect | Flexible development standards via PUD process |
TIF
TIF Districts
spec30+ designated Tax Increment Financing districts
| count | 30+ |
|---|---|
| effect | Tax increment financing for redevelopment; does not change zoning standards |
RRO
Rock River Overlay
FPRock River corridor and floodplain areas
| effect | Floodplain construction requirements and setback averaging along river |
|---|
CBD
Downtown CBD Overlay
DTDowntown Central Business District mapped area
| effect | Downtown design standards; mapped overlay not a base zoning district |
|---|
APO
Airport Overlay
APAirport approach zones
| effect | Height restrictions in airport approach zones |
|---|
Adopted building codes
No statewide building code
Click a code label to open its state-by-state adoption atlas.
Quirks & notes
- Article-based structure: zoning ordinance organized by articles rather than sequential chapters, creating complex cross-referencing
- 30+ TIF districts overlay the city, providing financial incentives but not modifying base zoning dimensional standards
- HPC holds Certified Local Government (CLG) status from SHPO for historic preservation review authority
- CBD overlay is mapped as a geographic overlay, not a base zoning district — properties retain base district classification
- Self-storage facilities prohibited in C-1, C-2, C-3, and C-4 districts since 2021 ordinance amendment
- PUD process triggered by ISR >= 0.60 (impervious surface ratio), creating form-based threshold for planned development review
- Rock River setback averaging: setbacks along Rock River may be averaged with adjacent parcels
- Interactive GIS system available for zoning verification
- Floodplain R-1 pockets: some R-1 zoned parcels fall within Rock River floodplain, constraining development
- No state-level density preemption: Illinois does not preempt local zoning for density
Formulas
Definitions
- height
- Measured to highest point of structure
- lot_coverage
- far
- du_ac
- impervious_cover
- PUD triggers at ISR >= 0.60
- setback_front
- Front setback; nonresidential in residential front setback <= 60 ft confirmed
- setback_side
- Side setback from property line
- setback_rear
- Rear setback from property line
- parking
Capacity calculations
- max_footprint_sf
lot_area_sf * lot_coverage- max_gfa_sf
lot_area_sf * far- max_units_from_density
lot_area_sf * du_ac / 43560- buildable_width_ft
lot_width_ft - setback_side_ft * 2- buildable_depth_ft
lot_depth_ft - setback_front_ft - setback_rear_ft- buildable_envelope_sf
buildable_width_ft * buildable_depth_ft- max_stories_approx
max_height_ft / 10- max_gfa_from_envelope
min(buildable_envelope_sf * max_stories_approx, max_gfa_sf)- parking_required
units * parking
Massing explorer
Interactive 3D comparison across every district. Drag to orbit, scroll to zoom, use the slider to walk districts, and toggle applicable overlays in the right-side panel.
Sort by
Max height
— ft
——
Floor area ratio
—
——
Lot coverage
—%
——
Setbacks (F / S / R)
— ft
——
Parking
— /unit
——
Max density
— du/ac
——
Min lot size
— sf
——
Copy zoning profile
Loading…
| District | Category | Height | FAR | Coverage | Setbacks | Parking | Density | Min lot | Overlays |
|---|
Research status
Data quality
35%completeness47 confirmed25 partial20 inferred
Documented gaps
- R-2 through R-4 dimensional standards
- All commercial district height/setback/FAR
- Industrial district standards
- Lot coverage across all districts
- Parking ratios
- Density standards
- Nonresidential setback rule details beyond 60 ft front
Known issues
schema:v1-legacypriority:lowdata:gaps-present
Other cities in this state
Nearest-alphabetical profiles. Click through to compare zoning patterns side-by-side.