Warren, MI Accessory Structures: Garage Conversions (2026)

29 of Warren's Zoning Ordinance treats garage conversions differently depending on whether the garage is attached or detached. Detached garages may never be converted to living space under subsection (b), full stop. Attached garages can be converted, but only as a fallback: the ordinance states the 'expansion of a residential dwelling to add living space is encouraged to be in the nature of a first or a second story addition,' and an attached garage conversion is permitted only where the applicant demonstrates a 'practical difficulty' in adding on conventionally.

Where that showing is made, eight conditions apply. The conversion must meet all applicable building, zoning, and construction codes. The garage door must come out and the exterior must be refinished to architecturally match the rest of the house. A replacement garage or storage shed has to be built, and the combined footprint of all structures on the lot, existing plus new, still can't exceed 30 percent of the lot. The homeowner must demonstrate at least two off-street parking spaces remain after the conversion. Only one driveway and approach is allowed, capped at 20 feet wide at the property line, and any new driveway must sit back three feet from the house and three feet from the property line (the property-line setback can be waived by the Building Department if engineered drainage is shown).

Where the converted space abuts an existing driveway, it needs a continuous eight-inch concrete curb, with the strip from the wall to the curb at least five feet wide and hard-surfaced. After conversion, the former garage area must function as an integral part of the single dwelling, not a separate use, such as a rental unit.