How Indianapolis Handles Accessory Structures: A Practical Guide

Indianapolis maintains 208 local ordinances across all categories, and 5 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Indianapolis falls on the strict-to-permissive spectrum compared to other cities.

ADU Rules

Indianapolis-Marion County's Consolidated Zoning Ordinance permits one secondary dwelling unit (ADU) per single-family detached lot, capped at 720 square feet, with an owner-occupancy requirement and one additional off-street parking space.

Key details: Code Section: Sec. 743-306-EE (Secondary Dwelling Unit). Units per lot: 1 per single-family detached dwelling. Maximum size: 720 sq. ft.. Owner occupancy: Required (owner must occupy primary or secondary unit). Parking: 1 additional off-street space.

Establishing a secondary dwelling unit without zoning approval and a building permit, exceeding the 720-square-foot cap, or renting out both units in violation of the owner-occupancy requirement can result in zoning enforcement by the Department of Metropolitan Development, including notices of violation, required correction, and denial of occupancy.

Carport Rules

Indianapolis-Marion County regulates carports as accessory structures under the 2016 Consolidated Zoning Ordinance, particularly Chapter 743 (Uses and Use-Specific Standards) and Chapter 744 (Development Standards). Detached accessory structures must be located in a side or rear yard, meet the underlying dwelling district's setbacks, and remain within accessory-structure height limits typically capped at 15 feet. Building permits are administered by the Marion County Building Department under Title III, Chapter 536.

Key details: Zoning Code: 2016 Consolidated Zoning. Use-Specific Ch.: Chapter 743. Dev. Standards Ch.: Chapter 744. Yard Placement: Side or rear (detached). Accessory Height: Typically 15 feet.

Erecting a carport without a Chapter 536 building permit, placing a detached carport in a front yard, or exceeding the 15-foot accessory-structure height or the 40 percent lot-coverage cap violates the 2016 Consolidated Zoning Ordinance and subjects the owner to stop-work orders, code-violation notices, and after-the-fact permitting through the Indianapolis Department of Business and Neighborhood Services and the Marion County Building Department.

Tiny Homes

Marion County permits tiny homes as long as they comply with the Indiana Residential Code; under Rev. Code Ch. 744 they require a permanent foundation, full utility hookups, and approved residential zoning.

Key details: Code Authority: Rev. Code Ch. 536 (IRC App. Q) + Ch. 744. Size Threshold: <=400 sq ft (IRC App. Q). Min Ceiling Height: 6 ft 8 in. Foundation: Permanent required. Utilities: Full water/sewer/electric required.

Occupying a tiny home without permits or in a non-permitted zone is a zoning violation under Ch. 744, with stop-occupancy orders and standard civil fines. RVs used as full-time dwellings face additional enforcement.

Garage Conversions

Indianapolis does not have a standalone garage-conversion ordinance; converting a garage to a secondary dwelling unit is governed by the secondary dwelling unit standards (Sec. 743-306-EE), and a unit built above a detached garage does not count against the accessory-building square footage cap.

Key details: Code Section: Sec. 743-306-EE (Secondary Dwelling Unit). Above-garage exception: Unit above an existing detached accessory building does not count toward accessory square footage. Size cap rationale: 720 sq. ft. cap sized to fit over a 24 ft x 30 ft garage. Parking: 1 additional off-street space required. State law: IC 36-7-4 (local control).

Converting a garage into habitable or rental space without zoning approval, a building permit, and (where required) replacement parking can result in stop-work orders, code-enforcement penalties, and an order to restore the structure or remove the unauthorized dwelling unit.

Shed Rules

Indianapolis defines a shed (mini-barn) as a minor residential structure and requires it to sit at least 5 feet from the rear lot line, meet the district's front and side setbacks, be smaller in footprint than the house, and stay shorter than the primary building.

Key details: Code Section: Sec. 743-306-A (General Conditions in the Dwelling Districts). Rear setback: 5 ft minimum from rear lot line. Front/side setback: District minimum front and side yard setbacks. Footprint limit: Less than the primary building footprint. Height: Less than primary building; max ~24-25 ft per district (Ch. 744).

Placing a shed before the primary dwelling is built, within 5 feet of the rear lot line, over a platted easement, or larger than the house footprint violates Section 743-306-A and can trigger Department of Metropolitan Development zoning enforcement, including removal or relocation of the structure.

The Bottom Line

Indianapolis's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Indianapolis is broadly strict or permissive.

This guide is based on Indianapolis's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.