Gary, IN Accessory Structures: ADU Rules (2026)

Section 123-1 of the zoning chapter defines an 'accessory dwelling unit' as a secondary independent dwelling unit constructed on a lot with a primary dwelling unit, built auxiliary to and smaller than the primary dwelling. That is the entire operative text: the term appears nowhere else in the code except a cross-reference inside the 'Cottage' definition. Gary's residence districts, R1 through R7 (§§ 123-155 through 123-161), and business districts B1 through B5 (§§ 123-192 through 123-196), each list their own permitted, transitional, and special land uses, and 'accessory dwelling unit' is not named on any of those lists.

Because Gary's zoning scheme is permissive, meaning a use must be listed to be authorized, a homeowner cannot build a second dwelling unit on a single-family lot as of right anywhere in the city. The only route is the Board of Zoning Appeals, which under § 123-30(g)(2) and (3) hears applications for variations from the district regulations and can authorize a use that would otherwise conflict with the chapter where literal enforcement works an unnecessary hardship. There is no city-published minimum lot size, floor-area cap, owner-occupancy requirement, or setback specific to accessory dwelling units; whatever conditions apply would be attached by the BZA itself, drawing on the general accessory-building bulk limits in § 123-332, such as the 40 percent rear-yard coverage cap and 15-foot height limit for accessory structures.