Frequently Asked Questions
Indiana ADU answers.
How much does an ADU cost in Indiana?
ADU costs in Indiana typically range from $120,000 to $230,000 for a detached unit, with the highest costs in Indianapolis. Garage and basement conversions run lower, often $50,000–$115,000.
Does Indiana have a statewide ADU law?
No — Indiana remains local control for ADU siting and permitting. NationwideADU's September 16, 2026 review found that Public Law 73 (HB 1001), signed March 4, 2026, added a statewide statutory definition of "accessory dwelling unit" — capped at the lesser of 75% of the primary home's habitable floor area or 1,000 sq ft — effective July 1, 2026. The same law requires every city, town, and county to hold a public hearing and file a report by January 1, 2027 on whether to loosen zoning to allow more housing, including ADUs — a study-and-report requirement with no automatic effect if a local government declines to act. An earlier Senate-engrossed version of the bill (February 24, 2026) would have gone further, making ADUs a protected permitted use statewide unless a local government opted out by December 31, 2026, but that stronger language did not survive to the final signed law. City, county, zoning, building, utility, and site rules still control whether and how ADUs may be built; verify the current rules for the property before design or construction.
Did Indiana pass a law requiring cities to allow ADUs?
Not automatically. An engrossed Senate version of HB 1001 (February 24, 2026) would have protected ADUs as a permitted use statewide unless a local government opted out by December 31, 2026, and would have barred added parking requirements and ADU-specific impact fees. Senators raised "one-size-fits-all" concerns during floor debate, and that permitted-use language was removed before the bill was enrolled and signed as Public Law 73 on March 4, 2026. What actually passed adds a statewide ADU definition and requires every local government to hold a public hearing and file a report by January 1, 2027 on whether to allow more housing types, including ADUs — a study mandate, not a requirement that any city or county actually allow them.
Do I need to live on-site to have an ADU in Indianapolis?
Indianapolis has historically required the property owner to live on-site, either in the primary residence or the ADU. Indiana's 2026 Public Law 73 added a statewide ADU definition but did not preempt local owner-occupancy rules, so Indianapolis retains authority here — confirm the current status directly with the Department of Metropolitan Development, since this rule has been under review.
How long does it take to get an ADU permit in Indianapolis?
The representative ADU permit-review planning timeline for Indiana is 5–10 weeks total (Indianapolis). This is not a statewide deadline or guarantee. Timing can change with the local authority, project complexity, corrections, utilities, site conditions, and application completeness; confirm the current timeline locally.
What is the cheapest ADU to build in Indiana?
Garage conversions are generally the least expensive option, typically $50,000–$110,000, using an existing structure to significantly cut cost versus new detached construction.
How much are ADU permit fees in Indiana?
The representative ADU permit-fee planning range for Indiana is $700 – $4,000. This is not an official statewide fee schedule or quote. Plan review, utility, impact, site, and other local charges may be additional; request a current itemized estimate from the permitting authority.
What is the ROI on an ADU in Indiana?
The adopted Indiana one-bedroom planning range is $800–$1,175 per month, derived from the HUD FY2026 revised FMR market basket under ROI-CM-1.4. Payback is calculated from the homeowner's budget, ADU type, size, rent range, and a 30% operating-expense reserve. Property value uses a 15% national planning input with a 10%–20% uncertainty range; it is not a valuation.
