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Evansville, IN Accessory Structures: ADU Rules (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified August 2026

ADU rules in Evansville, IN, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Floor area: 400–800 sq ft
Minimum lot size: 5,000 sq ft
Rear setback: 10 feet minimum
Lot coverage bonus: up to +10%
Limit: 1 ADU per lot

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Indiana under recent ADU streamlining laws. The Evansville, IN rules below cover local size, height, and setback requirements.

Summary

Evansville allows one accessory dwelling unit per single-family or duplex lot, sized between 400 and 800 square feet, only on lots of at least 5,000 square feet.

(1) Size in floor area (using outside measurements): minimum – 400 square feet; maximum – 800 square feet or the floor area of the principal structure, whichever is less.
(2) The minimum rear setback shall be 10 feet, while all other setbacks shall meet the minimum setbacks in EMC 18.130.010 Table A, Standards for Principal Buildings on Individual Lots, unless located in an existing, lawfully constructed, accessory building to be converted to an ADU.
(3) EMC 18.130.070(B)(5), allowing residential accessory structures to be located within two feet from any side or rear lot line, does not apply to ADUs.
(4) Shall only be permitted on lots that are 5,000 square feet or larger.
(5) Shall be allowed to increase the lot coverage in EMC 18.130.010 Table A by a maximum of 10 percent above the percentages shown in the table for the appropriate zoning districts.
(B) General ADU Requirements.
(1) Only one ADU shall be permitted per principal residential structure.
(2) Shipping or storage containers, mobile homes, recreational vehicles, other motor vehicles, travel trailers, and boats shall not be permitted as an ADU.
(3) Must remain accessory to the principal residential use and shall not be sold separately, or otherwise be divided from, the principal use.
(4) Shall not be built on a vacant lot prior to the construction of a principal structure, however it may be built simultaneously with or after the principal structure.

View official code

Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance G-2026-12, passed June 22, 2026).

Full Breakdown

EMC 18.130.072(A) sets the dimensional rules for accessory dwelling units: floor area must run from 400 up to 800 square feet, capped at the size of the principal house if that's smaller, and the lot must be at least 5,000 square feet. An ADU needs a 10-foot minimum rear setback and otherwise follows the district's normal setbacks, though it may push lot coverage up to 10 percent above the table's usual cap. Only one ADU is allowed per principal structure, and it's permitted solely on lots where a single-family home or duplex is the principal use.

Violations & Fines

Exceeding the 800-square-foot cap, building on an undersized lot, or adding a second ADU is a Title 18 violation that can block issuance of the improvement location permit.

Frequently Asked Questions

How big can an ADU be in Evansville?

Between 400 and 800 square feet, capped at the main house's floor area if smaller, under EMC 18.130.072(A)(1).

What's the minimum lot size for an ADU in Evansville?

5,000 square feet, per EMC 18.130.072(A)(4).

Sources & Official References

[1]Evansville Municipal Code § 18.130.072 – Accessory dwelling units (ADUs) (Code Publishing)

Other rules in Evansville

Fence Regulations: Height LimitsSome Restrictions Shed & Carport RulesSome Restrictions Parking Rules: RV & Boat ParkingSome Restrictions ADU Owner OccupancySome Restrictions Noise Ordinances: Aircraft NoiseSignificant Restrictions Parking Rules: Towing & Impound RightsSignificant Restrictions Parking Rules: EV ChargingFew Restrictions Fence Regulations: Fence Permit RequirementsSome Restrictions

All Evansville rules

How Evansville compares: Easiest Cities to Build an ADU·Compare Evansville to another location·View the Indiana accessory structures overview

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