Are ADUs, granny flats, or in-law suites allowed in Birmingham, MI?

No. Birmingham does not permit accessory dwelling units, granny flats, or detached in-law cottages. The term "accessory dwelling" appears nowhere in the zoning ordinance, and § 4.02 affirmatively prohibits residential occupancy of accessory buildings in residential districts. Unlisted uses are not permitted (§ 1.13), so the silence is itself the answer.

There is one narrow exception: in the MX mixed-use district on the Eton Road corridor, residential units in accessory structures are permitted (§ 4.07). MX does not cover single-family neighborhoods.

The closest allowance in single-family districts is the renting of rooms within your own dwelling, capped at 2 roomers per unit (§ 5.02(D)). In-law space inside the main house that shares the home is generally part of the one-family use; a separate second dwelling is not. A true second unit would require rezoning or some form of use relief.

Talk to the Planning Division at 248-530-1850 before purchasing or designing.