Mount Prospect, IL Accessory Structures: Garage Conversions (2026)

Section 14.315 of the Village of Mount Prospect zoning chapter is titled Conversion of Single-Family Residential Attached Garages. It permits the conversion of an attached garage into living space, but only subject to three conditions plus all other applicable regulations within the zoning code.

The first condition is replacement parking. A new garage space equal to or greater than the amount being converted must be provided, and it has to provide sufficient space to park the same number of vehicles as the garage being converted. A homeowner with a two-car attached garage therefore cannot convert it and keep only a one-car space.

The second condition is appearance. The garage door that gives access to the area being converted must be removed and replaced with exterior materials similar in style and color to the home's exterior. The converted space cannot keep a garage door front.

The third condition is the driveway. The existing driveway that served the converted garage area must be removed, and a driveway serving the new garage must be provided in conformance with Section 14.2204 of the zoning chapter. That cross-reference pulls the new driveway into the Village's off-street parking and loading article.

Because the section says all other applicable regulations within the code still apply, the new garage and the converted room also have to meet the zoning bulk rules, such as setbacks and lot coverage, and the Village building requirements. The section addresses only attached garages on single-family residential property.