Indiana Building Permit Guides

Indiana’s building rules are adopted by the Fire Prevention and Building Safety Commission and administered by the Indiana Department of Homeland Security (IDHS). The commission’s General Administrative Rules (675 IAC 12) set out how a project is processed, and the first question they ask is whether the building is a Class 1 or a Class 2 structure.

Class 1 or Class 2

Under IC 22-12-1-4 a Class 1 structure is a building or structure that is intended to be, or is, occupied or otherwise used in any part by:

• the public;
• three or more tenants; or
• one or more persons who act as the employees of another.

The definition also covers site improvements that affect access for people with disabilities, outdoor event equipment, and a structure containing three or more condominium units that are not completely separated by unimproved space. It excludes buildings used only for an agricultural purpose on the land where they stand and not used for retail trade (a farm-produce stand open eight months or less a year is allowed), vehicular bridges, and structures occupied only to maintain or repair the structure or its equipment.

⚠️ The employee test is part of the definition: a building used by even one person working as another’s employee is a Class 1 structure, whatever its size.

A Class 2 structure (IC 22-12-1-5) is a building with one or two dwelling units, or a townhouse, together with outbuildings such as a garage, barn or family pool, unless any part is regularly used as a Class 1 structure. A townhouse is a single-family unit in a group of three or more attached units, each running from foundation to roof, no more than three stories high, separated by fire-resistance-rated walls and with open space on at least two sides.

Under 675 IAC 12-6-3, no construction may be done on a Class 1 structure until a Construction Design Release has been issued, unless the work is exempt. The release is issued by IDHS or by a city, town or county that the commission has certified to issue releases (IC 22-15-3-1). Starting construction of a Class 1 structure without a release is a Class C infraction for the people doing and controlling the work (IC 22-15-3-7).

Deadlines on the state review

IDHS may issue a release without a plan review. Within 10 business days of a complete application it must either tell the applicant that a release will be issued or that a plan review will be done; a plan review has 20 business days, and each set of corrections 10 business days. If IDHS misses one of those deadlines, the applicant receives the release, or a confirmation number that serves as a temporary release (IC 22-15-3.2-7 to -10).

Foundation and partial releases

A foundation release allows work to grade level only, including a slab on grade and underground mechanical, electrical and plumbing work, but not more than one floor below grade; it must be requested when the application is filed (675 IAC 12-6-14). A partial design release allows construction to the extent of its scope and no further (675 IAC 12-6-15).

Work that needs no release

675 IAC 12-6-4 lists exempt work. For new construction it includes temporary structures, federal property, one-story detached storage or equipment buildings up to 500 square feet, open-sided shelters up to 500 square feet, kiosks and similar buildings up to 200 square feet, most fences and retaining walls, and model homes built to Class 2 rules. For alterations it includes like-for-like plumbing, electrical and mechanical replacements, small fixture and branch-circuit additions, heating systems up to 400,000 Btu/h and cooling systems up to 15 tons, finish work, and limited sprinkler changes. Exempt work must still meet the commission’s rules, and it is not exempt when it is part of a project that needs a release.

When an architect or engineer is required

A registered architect or professional engineer must prepare the plans for Class 1 work that needs a release, except for structures of 30,000 cubic feet or less, additions of 30,000 cubic feet or less, alterations that do not affect structural safety, and sprinkler work designed by a qualified person (675 IAC 12-6-9; IC 22-15-3-3). The threshold is volume, not floor area or cost.

The release must be posted on the site, and a complete set of the released plans kept there until the building is occupied (675 IAC 12-6-19).

Each city, town and county must require compliance with the commission’s code (IC 36-7-2-9), and the building permit, inspections and certificate of occupancy come from the local building department where one exists. Whether a building permit is required at all for Class 2 work, and for which work, is set by local ordinance. A county ordinance for unincorporated areas takes effect only once the commission approves it, and it does not apply to private homes built by individuals for their own occupancy (IC 36-7-8-3).

Local review of Class 1 plans

Where a city, town or county reviews Class 1 plans itself, it has 20 business days to accept a complete application or ask for corrections, and 10 business days for each set of corrections; if it fails to send a required notice, it may not prohibit construction on that ground (IC 22-15-3.3-7 and -8). A local review does not replace the state design release (IC 22-15-3.3-5).

Class 2 permits since 1 January 2026

Where a unit requires permits for Class 2 work, IC 36-7-2.5 now sets deadlines. The unit must say within 3 business days whether an application is complete, finish any plan review within 7 business days of confirming it is complete, and say whether it can carry out inspections within 3 business days of a request. The applicant may instead use a private provider — a registered architect, professional engineer or ICC-certified building official not tied to the project — at its own cost; if the unit cannot meet its deadlines and the applicant switches, the unit refunds its review or inspection fees less a convenience fee of no more than $100. If the unit misses the plan review deadline it stated, it must issue a permit, or a limited permit, by the next business day.

The codes in force are those in the current 675 IAC:

• 2014 Indiana Building Code (675 IAC 13-2.6), based on the 2012 International Building Code, in effect since 1 December 2014.
• 2020 Indiana Residential Code (675 IAC 14-4.4), based on the 2018 International Residential Code, in effect since 26 December 2019, for Class 2 structures.
• Indiana Electrical Code, 2009 Edition (675 IAC 17-1.8), based on the 2008 National Electrical Code.
• 2012 Indiana Plumbing Code (2006 IPC), 2014 Indiana Mechanical Code (2012 IMC), 2014 Indiana Fuel Gas Code and 2014 Indiana Fire Code (2012 IFC).
• 2010 Indiana Energy Conservation Code (675 IAC 19-4), based on ASHRAE 90.1-2007, for buildings other than low-rise residential.

IDHS has published a proposed 2026 Indiana Building Code based on the 2024 International Building Code; it is not yet part of the current Administrative Code. Check the edition in force on your filing date.

The state design release fee is paid to the fire and building services fund with the application (675 IAC 12-3-2). It is a $75 filing fee plus a processing fee of at least $75. For most buildings the processing fee is $0.050 per gross square foot of floor area; warehouses, hangars, open parking structures, truck terminals and similar low-occupancy uses pay $0.030; remodelling without additions pays $0.0030 per square foot of the work. Other categories cover pools, tanks, replicated floor plans and shell buildings. A foundation release costs $80, an extension or reinstatement $50, and expedited review $5,000 on top of the normal fees.

Local permit and plan review fees are separate and set by each city, town or county.

The state licenses plumbing contractors and journeyman plumbers through the Indiana Plumbing Commission (IC 25-28.5). Acting as a plumbing contractor or journeyman plumber without a licence is a Class A misdemeanor (IC 25-28.5-1-31). A city, town or county may require a licensed plumbing contractor to register locally, but may not require any other licence (IC 25-28.5-1-33).

The state issues no licence for electrical, HVAC or general contractors; the Professional Licensing Agency’s list of licensed professions includes plumbing but none of those trades. Cities, towns and counties set any registration or licensing requirement for them, so check it for each jurisdiction.

A design release expires if construction on all buildings within its scope has not started within one year. IDHS may extend it once, by up to 180 days, if nothing in the plans or the applicable rules has changed. If work is suspended or abandoned for 180 days after it starts, it may resume only after a reinstatement (675 IAC 12-6-20). Changes to the design or scope after a release is issued need an addendum or revised release (675 IAC 12-6-18).

The local building permit has its own validity period, set by the issuing department. On a Class 1 project, track the state release and the local permit separately.