Ohio Building Permit Guides

Ohio’s construction codes are adopted statewide by the Ohio Board of Building Standards, part of the Department of Commerce’s Division of Industrial Compliance. Under Ohio Revised Code (ORC) 3781.10 the Board adopts separate nonresidential and residential building codes and certifies municipal, township and county building departments to enforce them.

🏛 Enforcement authority comes from certification. A building department may approve plans and make inspections only if the Board has certified it, and it may enforce only the type of code for which it is certified: the nonresidential code, the residential code, or both (ORC 3781.10(E)). A department certified for new residential construction needs a separate certification to enforce the residential code for the repair and alteration of existing homes. So the first question on any Ohio project is which certified department, if any, has authority over the address for that type of work.

Two codes, and the line between them

• Ohio Building Code (OBC): all buildings other than detached one-, two- and three-family dwellings, together with the Ohio Mechanical Code and Ohio Plumbing Code.
• Residential Code of Ohio (RCO): detached one-, two- and three-family dwellings and structures accessory to them.

⚠️ Ohio draws the residential line at three-family dwellings: the Ohio codes read the International Codes’ “one- and two-family” as “one-, two- and three-family” (OBC 101.1.1). Confirm which code governs before drawings are developed.

Which editions apply

The current Ohio Building Code, Ohio Mechanical Code and Ohio Plumbing Code took effect on 1 March 2024 and are based on the 2021 International Codes with Ohio amendments; their administrative chapters were last amended on 15 October 2025. The Residential Code of Ohio in force is the 2019 edition, based on the 2018 International Residential Code. Both codes reference the 2023 National Electrical Code (NFPA 70), the residential code since 15 April 2024.

How far local rules can go

Residential rules are uniform statewide wherever a certified residential department operates. A local code may differ from the RCO only on subject matter the RCO does not address, or through ORC 3781.01, under which the Board decides whether a local residential regulation conflicts with the state code and, if it does, whether it is valid (ORC 3781.10(A)(2), 3781.01). For nonresidential buildings, the Board’s rules are the lawful minimum, and municipalities may make further regulations that do not conflict with state law or the Board’s rules (ORC 3781.01; OBC 102.2).

⚠️ Get approval before work begins. No owner may proceed with the construction, erection, alteration or equipment of a building until the plans have been approved as the law requires (ORC 3791.04(B)).

🔍 Where no certified department has jurisdiction, the answer depends on the building type. Plans for a nonresidential building then go to the Superintendent of Industrial Compliance at the state. Where no department certified for residential buildings has jurisdiction, the owner is not required to submit plans for a house at all (ORC 3791.04(A)(1)).

The Board publishes a building-department look-up that identifies, by address, the entity or entities with commercial or residential code enforcement authority; the Board asks owners to confirm that authority with the listed department. Buildings on property owned by the State of Ohio are handled by the Division of Industrial Compliance.

What the state decides, and what the local department decides

The state adopts the codes, certifies the departments and their personnel, reviews and inspects nonresidential work where no certified department has jurisdiction, and licenses five commercial trades through the Ohio Construction Industry Licensing Board. The certified department reviews plans, makes inspections and issues approvals and certificates of occupancy, and its political subdivision sets the fees (ORC 3781.102(E)).

Plumbing is also enforced by boards of health of health districts, and building sewers by the city engineer, the health district or the sewer purveyor (ORC 3781.03(C)–(D)), so a plumbing permit or inspection may come from a different office than the building department.

Zoning is a separate approval, and often a separate office

A building approval confirms code compliance. Whether the use, setbacks, parking and site layout are allowed is a zoning question, administered separately, often by a municipal or township zoning office rather than the building department.

Two parts of the code set shape most submittals.

The first is energy. Commercial buildings follow the 2021 International Energy Conservation Code or ASHRAE 90.1-2019, as modified by Chapter 13 of the OBC. Houses follow Chapter 11 of the RCO, which offers several compliance paths, including the International Energy Conservation Code.

The second is existing buildings. The International Existing Building Code, as modified by Chapter 34 of the OBC, controls the alteration, repair, addition, maintenance, relocation and change of occupancy of existing nonresidential buildings (OBC 102.7), and a change of occupancy requires construction documents to be submitted for approval even without other work (OBC 107.1).

Each certified department’s political subdivision sets its own fees for plan approval and inspections (ORC 3781.102(E)). On top of those fees, the department collects for the Board of Building Standards 3 percent of its fees on nonresidential buildings and 1 percent of its fees on new residential buildings, and 1 percent on residential repair and alteration where it enforces the RCO for that work (ORC 3781.102(F)).

Fee schedules are revised on each jurisdiction’s own cycle, so ask the department for the schedule in force on your filing date, and ask separately about plan review, trade, re-inspection and revision charges.

💼 The Ohio Construction Industry Licensing Board (OCILB) licenses five trades: electrical, heating, ventilating and air conditioning (HVAC), hydronics, plumbing and refrigeration contractors (ORC 4740.01). The licences cover commercial work: the statute’s “construction project” excludes residential buildings. No one may act as one of these contractors without the licence (ORC 4740.13), and the Board’s application requires proof of at least $500,000 of contractor liability insurance.

The state licenses no other contractors, so general contractors and residential contractors are licensed or registered, if at all, by local governments. A local rule that registers contractors and charges a fee must also require the state licence of contractors in the five licensed trades (ORC 4740.12), and a board of county commissioners may license electrical and HVAC contractors who do not need a state licence (ORC 3781.102(B)).

Home construction contracts are covered by ORC Chapter 4722. For construction, repair, improvement or renovation of a one-, two- or three-family dwelling costing $25,000 or more, the supplier must use a written contract that includes the details the law lists, carry at least $250,000 of general liability insurance, and take a down payment of no more than 10 percent of the contract price, with an exception for special-order items (ORC 4722.01–4722.04). The Attorney General enforces the chapter, and owners have their own right of action (ORC 4722.06–4722.08).

Before filing, ask the issuing department whether it has authority over the address for the work (for alterations to an existing home, whether it is certified to enforce the RCO for repair and alteration), whether the OBC or the RCO governs, and which approvals must be in hand first.

📅 Approvals expire. Approved plans become invalid if work has not started within twelve months; one twelve-month extension is granted if the owner asks at least ten days before the approval expires and pays a fee of up to $100. If work is suspended for more than six months the approval also lapses, with two six-month extensions available on the same terms (OBC 105.6–105.7; RCO 105.3–105.4).

No building may be used or occupied until the building official issues a certificate of occupancy or a certificate of completion (OBC Section 111; RCO 111.1). Because a change of occupancy needs approved construction documents (OBC 107.1), moving a new use into an existing space can need approval even when no construction is involved.

Address correction notices before asking for a re-inspection, do not cover work before it has been inspected and approved, and keep the issued approval and the approved plans on site.