Indianapolis, IN Accessory Structures: Garage Conversions (2026)

Indianapolis-Marion County's Consolidated Zoning Ordinance contains no use-specific section titled 'garage conversion,' so converting a garage to living space is regulated through the secondary dwelling unit standards in Section 743-306-EE and the general dwelling-district accessory standards in Section 743-306-A. A detached secondary dwelling unit normally counts toward the total allowable square footage allocated for accessory buildings, but the ordinance creates an explicit exception when the unit is built above an existing detached accessory building (such as a garage), in which case it does not count against the accessory-building square footage.

The 720-square-foot cap on a secondary dwelling unit was set specifically to fit over a 24-foot by 30-foot garage, indicating the ordinance contemplates above-garage conversions. Any converted unit must satisfy the owner-occupancy requirement, provide one additional off-street parking space, and include a separate, code-compliant entrance. In the Compact Context Area, a detached secondary dwelling unit may only exist within a permitted accessory building. Conversions also remain subject to the Indiana building code and require building permits administered through the Department of Business and Neighborhood Services; converting a required parking garage may also require providing replacement off-street parking. Because Indiana follows local control under IC 36-7-4, there is no state statute overriding these local garage-conversion rules.