Ohio building code

Codes in force in Ohio

Each code family with the edition and the date it took effect, as the adopting agency or statute states them.

Scope, amendments and transition rules

International Residential Code (IRC)

Scope

Statewide; applies everywhere¹

Applies to

One-, two- and three-family dwellings; enforced by BBS-certified local residential building departments¹

Next edition (not yet in force)

Proposed, not adopted: Residential Code of Ohio rules 4101:8-1-01 to 4101:8-44-01 (Amendments Group 107), public hearing December 4, 2026; still based on the 2018 IRC³

National Electrical Code (NEC): National Electrical Code, NFPA 70 (as incorporated in RCO 3401.1)

Scope

Statewide; applies everywhere¹

Applies to

One-, two- and three-family dwellings and their accessory structures (RCO)²

Next edition (not yet in force)

Proposed, not adopted: Residential Code of Ohio rules 4101:8-1-01 to 4101:8-44-01 (Amendments Group 107), public hearing December 4, 2026; still based on the 2018 IRC³

National Electrical Code (NEC): National Electrical Code (NFPA 70-23)

Scope

Statewide; applies everywhere¹

Applies to

Buildings under the Ohio Building Code (non-residential and buildings other than 1-3 family dwellings)¹

International Building Code (IBC)

Scope

Statewide; applies everywhere¹

Applies to

Non-residential buildings and buildings other than 1-, 2- and 3-family dwellings (agricultural buildings excepted)¹

Amendments

Amendments to the 2024 OBC, OMC and OPC effective October 15, 2025¹¹

International Mechanical Code (IMC)

Scope

Statewide; applies everywhere¹

Applies to

Non-residential buildings and buildings other than 1-, 2- and 3-family dwellings (agricultural buildings excepted)¹

Amendments

Amendments to the 2024 OBC, OMC and OPC effective October 15, 2025¹¹

International Plumbing Code (IPC)

Scope

Statewide; applies everywhere¹

Applies to

Non-residential buildings and buildings other than 1-, 2- and 3-family dwellings (agricultural buildings excepted)¹

Amendments

Amendments to the 2024 OBC, OMC and OPC effective October 15, 2025¹¹

International Existing Building Code (IEBC)

Scope

Statewide; applies everywhere¹

Energy code, residential

Scope

Statewide; applies everywhere¹

Next edition (not yet in force)

Proposed, not adopted: Residential Code of Ohio rules 4101:8-1-01 to 4101:8-44-01 (Amendments Group 107), public hearing December 4, 2026; still based on the 2018 IRC³

Energy code, commercial

Scope

Statewide; applies everywhere¹

International Fire Code (IFC)

Scope

Statewide; applies everywhere⁹

Applies to

Fire safety for structures, buildings, premises, vehicles and other locations in Ohio⁹

How Ohio adopts building codes

ORC Chapters 3781 and 3791; OAC 4101:1 (OBC), 4101:2 (OMC), 4101:3 (OPC), 4101:8 (RCO); OAC 1301:7-7 (Ohio Fire Code)

• ORC Chapters 3781 and 3791. Building codes, building department certification & IU rules — RC Chapters 3781 and 3791…¹²
• OAC 4101:8. Residential Code of Ohio — OAC 4101:8…¹²
• Board adopts building, mechanical, plumbing codes. Formulate , adopt, and amend the Building, Mechanical, Plumbing, Elevator, Boiler, and Pressure Piping Codes.¹³
• Board certifies municipal, county and township building departments to enforce codes. Certify municipal, county, and township building departments to exercise enforcement authority and to accept and approve plans and specifications, and make inspections and to inspect power, refrigerating, hydraulic, heating, oxygen and other gaseous piping, and liquefied petroleum gas piping systems.¹³
• Residential: RCO enforced by certified local departments. One-, two-, and three-family residential dwellings are regulated locally by certified residential building departments.¹
• RCO adopted by BBS. The RCO is based upon the International Residential Code and adopted by the Ohio Board of Building Standards (BBS).¹
• Non-residential: OBC/OMC/OPC. In Ohio, all non-residential buildings (other than 1-, 2-, and 3-family dwellings, and agricultural buildings) are required to comply with the requirements of the Ohio Building, Mechanical, and Plumbing Codes.¹
• 2024 OBC/OMC/OPC on 2021 I-Codes. On Aug. 11, 2023, the Ohio Board of Building Standards adopted the 2024 Ohio Building Code (OBC), Ohio Mechanical Code (OMC), and Ohio Plumbing Code (OPC) by incorporating the 2021 International Codes (I-Codes) with Ohio amendments.⁶

Applies to

One-, two- and three-family dwellings under the RCO; other buildings under the OBC¹

Residential code in Ohio cities

The edition each city enforces, from the city’s own adoption page or ordinance.

For permits, exemptions and owner-builder rules, see Ohio building permits. To compare editions across states, see the code adoption map.