# Westmont R districts accessory buildings and ADUs | BV360 Pre-Flight

Westmont limits the number, size, placement, and height of detached accessory buildings and permits ADUs on detached single-family lots.

## Plain English

An R-zoned lot may have one detached garage plus up to two additional non-garage accessory buildings. Their combined footprint may not exceed 1,250 square feet, and they count toward lot coverage.
Accessory buildings are allowed in rear and street-side yards, not front yards, and must be at least 5 feet from rear and side lot lines. The height limit is 18 feet or the principal building height, whichever is less. An ADU is allowed on a detached single-family lot and does not require additional parking.

## Numbers Pre-Flight checks

| Field | Value | Source |
| --- | --- | --- |
| Accessory footprint, all buildings combined | 1,250 sq ft maximum | Sec. 7.02 |
| Accessory height | 18 ft or principal height, whichever is less | Sec. 7.02 |
| Accessory rear / side setback | 5 ft minimum | Sec. 7.02 |
| ADU parking | No additional parking required | Sec. 7.05 |

Official source: Village of Westmont Zoning Ordinance · Secs. 7.02 and 7.05 (https://westmont.illinois.gov/DocumentCenter/View/5043/VillageofWestmentZoningOrdinance-AsAmended-May-28-2026?bidId=). Effective / last checked: Amended through May 28, 2026.

Pre-Flight is not a permit, not legal advice, and not a substitute for a licensed design professional or the authority having jurisdiction. The city still decides.