5 county-level rules, plus city-specific rules for 1 city in Marion County, Indiana.
Verified from official government sources
ADUs are permitted in most Indianapolis-Marion County residential zones under the Consolidated Zoning Ordinance. Must be secondary to the primary dwelling; subject to setbacks, height limits, and design standards. No statewide IN ADU mandate — fully local. Permits required from DBNS.
Accessory structures in Indianapolis require permits for structures over 144 sq ft or those with electrical or plumbing. Governed by Indiana Residential Code (IRC 2018) and the Consolidated Zoning Ordinance. Setbacks per zoning district. DBNS: 317-327-2684.
Garage conversions to living space or ADUs in Indianapolis require building permits and must comply with the Consolidated Zoning Ordinance. No statewide ADU mandate in Indiana; local zoning governs. ADU provisions of Code Ch. 744 apply to converted garages.
Carports in Marion County require a building permit from DBNS and must comply with Consolidated Zoning Ordinance accessory structure setbacks. Typically 3 to 5 foot side setbacks. Pre-fab kits are not permit-exempt.
Marion County treats foundation-built tiny homes as standard dwellings under the Indiana Residential Code (Appendix Q allows under 400 sq ft). Tiny homes on wheels are classified as RVs and cannot be used as permanent residences in residential zones.
1 cities in Marion County have their own accessory structures rules. Each link goes to that city's dedicated page with code citations.
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Marion County Ordinance Hub →