Permit Required? Required
Typical Fee Range $1,000–$2,500 Includes $150–$200 ILP plus structural and trade permit fees.
Fee Method Project-based
Apply Online Apply at Indianapolis Department of Business and Neighborhood Services →

What's Required in Indianapolis

  • ADUs must be between 220 and 800 square feet
  • ADU cannot exceed 50% of the primary dwelling's living space
  • Property must be owner-occupied (either main house or ADU)
  • Must include independent kitchen and bathroom facilities
  • ADU must comply with all standard setbacks for accessory structures in the specific zone
  • Independent utility connections (water/sewer) are required per local standards

How Much Does an ADU Permit Cost in Indianapolis?

Budget $1,000–$2,500 for the Indianapolis permit itself (project-based), issued by the Indianapolis Department of Business and Neighborhood Services — but treat that as the entry fee, not the total. ADUs are full dwelling units, so the permit stack usually includes building, electrical, plumbing, and mechanical trade permits, plus plan review. One local note: includes $150–$200 ILP plus structural and trade permit fees. Get an itemized fee estimate from the department before finalizing your budget; the spread between a simple conversion and a new detached build is wide.

ADU Size Limits and Zoning Rules in Indianapolis

Before drawing plans, check the two gates that sink most ADU projects: size and zoning. Size ceilings vary by lot and ADU type (attached, detached, or conversion), so confirm your specific configuration. Other recorded conditions: property must be owner-occupied (either main house or ADU). Setbacks, height limits, and utility connections layer on top of those rules. The Indianapolis Department of Business and Neighborhood Services can confirm what your specific lot allows — worth doing before you pay for architectural drawings rather than after.

How to Get a ADU Permit in Indianapolis

1

Step 1: Zoning

Verify ADU eligibility and setbacks for your parcel via MapIndy.

2

Step 2: Architecture

Hire an architect to create full construction documents.

3

Step 3: Portal Submission

Submit 'New Accessory Structure' for the ADU unit via ACA.

4

Step 4: Fee Payment

Pay structural ($697+), ILP, and trade fees online.

5

Step 5: Inspections

Schedule full sequence: Foundation, Framing, Rough MEP, and Final.

Frequently Asked Questions

Yes, provided you meet size (220-800 sq ft) and owner-occupancy requirements.
Fees typically start around $1,000 for building and utility permits.
800 square feet or 50% of the main house, whichever is smaller.