Union County, Ohio Building Permit Guide

Building permits across most of Union County come from the Union County Building Department at 233 West 6th Street in Marysville, which the Ohio Board of Building Standards certifies for commercial and residential work. The department serves the townships and, by agreement, Marysville, Richwood, Milford Center and Magnetic Springs. Union was Ohio’s fastest-growing county between 2020 and 2025 in Census Bureau estimates, rising from 62,795 to 73,446 people.

This guide covers the department and how to reach it, the local conditions that shape a filing here, what permits cost and who may pull them, and how inspections are booked. Rules that apply everywhere in Ohio are summarized in each section, with a link to the full statewide explanation.

This guide covers the areas served by the county department: the townships, the City of Marysville and the villages of Richwood, Milford Center and Magnetic Springs. The City of Dublin’s own building department covers all of Dublin, including its Union County part, and the West Jefferson Building Department is the permitting authority inside Plain City. No department is certified for the Village of Unionville Center, so houses there need no state or county building permit and commercial plans go to the state Division of Industrial Compliance (ORC 3791.04).

What requires a building permit in Union County?

Under the Ohio Building Code and the Residential Code of Ohio, a permit is required for most construction activity.

The exempt list is set statewide in Section 102.10 of the Ohio Building Code and the Residential Code of Ohio, and an exemption from a building permit is not an exemption from zoning, setbacks, floodplain rules, utility approval or a fire authority review. Confirm scope with the department before work starts rather than after.

Which code edition applies

The county's certified departments enforce the statewide Ohio codes, so the technical standard is constant across the county. Fees, submittal processes, zoning frameworks, inspection scheduling and any additional local regulations are what differ.

Permits in Union County are governed by Ohio’s statewide codes: the Ohio Building Code for commercial and other nonresidential buildings, and the Residential Code of Ohio for detached one-, two- and three-family dwellings. The Ohio Building, Mechanical and Plumbing Codes in force since 1 March 2024 are based on the 2021 International Codes; the Residential Code of Ohio is the 2019 edition, based on the 2018 International Residential Code; both use the 2023 National Electrical Code. Only departments certified by the Ohio Board of Building Standards may approve plans, and residential rules are uniform statewide. How Ohio’s statewide code works

Who handles permitting in Union County?

Permits are issued by the certified department with authority over the address. Zoning is administered by the townships and cities, not by the county building department, which publishes township and city zoning contact information.

On unsewered parcels the board of health must approve the sewage treatment system after a site evaluation (ORC 3718.02), and a new private well needs a board of health permit (OAC 3701-28-03). Resolve both before a layout is fixed.

One point applies across every Ohio jurisdiction and is worth confirming rather than assuming. Residential rules are uniform statewide: a local code may differ from the Residential Code of Ohio only on subject matter the state code does not address, or after review by the Board of Building Standards (ORC 3781.10, 3781.01). Municipalities may add nonresidential regulations that do not conflict with the state rules. Ask the issuing department whether any local regulation affects your project type.

In 2025, building permits issued in unincorporated Union County authorized 968 new privately owned housing units, 595 of them single-family homes, according to the U.S. Census Bureau Building Permits Survey.

Zoning is a separate approval, and often a separate office

Zoning is a separate approval from the township or city. In Marysville a zoning permit is required before most property additions, and some projects need both a zoning permit and a building permit. Ask the township or city zoning contact what must be approved before the building application.

The Ohio Board of Building Standards certifies which departments may enforce the code, and for which buildings; the certified department’s political subdivision sets fees, and zoning is a separate approval. Where no certified department has jurisdiction, nonresidential plans go to the state, while houses need no plan submission. The Board’s building-department look-up shows which department has authority over an address. Who has authority in Ohio

Permit types

Residential permits

One-, two- and three-family dwellings follow the Residential Code of Ohio. The county publishes a property owner permit information sheet, residential permit requirements, a residential plan review checklist and guidance on finished basements, solar panels and pole buildings.

Commercial permits

Commercial buildings and residential buildings of four or more units follow the Ohio Building Code. The county publishes a commercial submittal checklist, a commercial plan review checklist, certificate of occupancy instructions and a special inspection final report form.

Two statewide topics shape most Ohio submittals: energy compliance (the 2021 IECC or ASHRAE 90.1-2019 for commercial buildings, Chapter 11 of the Residential Code of Ohio for houses) and work on existing buildings, where alteration, repair, addition and change of occupancy each carry their own requirements. Energy and existing buildings in Ohio

Union County permit costs and fees

Fees are set by whichever certified department issues the permit, and a Board of Building Standards assessment of 3 percent of nonresidential and 1 percent of residential fees is added (ORC 3781.102).

Fee schedules are revised on each jurisdiction’s own cycle, so ask the issuing department for the schedule in force on your filing date, and ask separately about plan review, trade, re-inspection and revision charges. A Board of Building Standards assessment of 3 percent (nonresidential) or 1 percent (residential) is added to local fees. How Ohio permit fees work

Trade permits and who may pull them

Ohio licenses five commercial trades statewide through the Ohio Construction Industry Licensing Board: electrical, HVAC, hydronics, plumbing and refrigeration. The state does not license general or residential contractors, so those are licensed or registered locally, if at all. Home construction contracts of $25,000 or more must be in writing under ORC 4722. Contractor licensing in Ohio

How to apply for a Union County building permit

Approved plans become invalid if work has not started within twelve months, with one twelve-month extension available. Before filing, confirm the department has authority over the address for the work, whether the Ohio Building Code or the Residential Code of Ohio governs, and which approvals must be in hand first. Review and corrections in Ohio

Inspections in Union County

The building official lists the required inspections when the plans are approved (OBC and RCO 108.2). Schedule through the county’s OpenGov portal, which allows a 7 a.m. cutoff for same-day inspections, or call the inspection line at 937-645-3019, which can take two business days. Since 1 July 2025 the county has offered optional virtual inspections for select inspection types.

Requests for after-hours inspections must be made 48 hours in advance, and the county publishes cold-weather concrete guidelines.

No building may be occupied until a certificate of occupancy or completion is issued, and a change of occupancy needs approved construction documents even without other work. Address correction notices before requesting a re-inspection, and do not cover work before it has been inspected and approved. Inspections and occupancy in Ohio

Union County permit search and official resources

Permit records sit with the department that issued them, which in Ohio makes record research a certification question first. A property may have records with a municipal department, a county department, a township department or the state, depending on who held authority at the time the work was done — and that can have changed if a department gained or gave up certification, or if the property was annexed. If you are buying, refinancing or renovating, ask the Union County Building Department what it holds for the parcel and whether earlier records may sit elsewhere.

The Board's building-department lookup helps here too: it establishes who has authority today, which is the right starting point even when the history is more complicated.

These are the primary sources behind this guide. Codes, fee schedules and portal procedures change. Confirm the position for your filing date.

• Union County Building Department
• Ohio Board of Building Standards
• BBS — find the building department for your address
• Ohio Construction Industry Licensing Board
• ORC Chapter 4722, home construction service contracts

Frequently asked questions

Who issues building permits in Marysville?

The Union County Building Department. Marysville, Richwood, Milford Center and Magnetic Springs contract with the county for building code services, while Marysville issues its own zoning permits.

Who issues permits in Dublin and Plain City?

The City of Dublin’s building department covers all of Dublin, including its Union County part, and the West Jefferson Building Department is the permitting authority inside Plain City.

How do I know which department issues my permit?

Use the Board of Building Standards building-department lookup, which maps an address to the department with authority over it. Only a BBS-certified department, or the state, may approve plans and issue permits, and certification does not follow automatically from being a city, county or township.

Does my project fall under the OBC or the RCO?

Commercial, industrial and public buildings follow the Ohio Building Code. One-, two- and three-family dwellings follow the Residential Code of Ohio. Ohio’s residential code reaches three-family dwellings, where the International Residential Code stops at two.

What if no certified department serves the area?

The Division of Industrial Compliance performs commercial plan review and inspection where no certified department serves. Residential code enforcement, however, is carried out only by certified local departments, so the fallback is commercial-only.

Does my general contractor need an Ohio licence?

There is no statewide general-contractor licence in Ohio. The state licenses five commercial trades through the OCILB — electrical, HVAC, hydronics, plumbing and refrigeration — while general contractors, and trade contractors on residential work, are licensed or registered only where a local government requires it. Home construction and improvement contracts of $25,000 or more on one-, two- and three-family dwellings must be in writing under ORC 4722, and the supplier must carry at least $250,000 of general liability insurance.

Simplify Union County permitting with Alliance Permitting

In Union County we confirm first whether the county, Dublin or West Jefferson issues the permit, then settle zoning with the township or city and book plumbing inspections with the Health Department.

Trusted by leading builders, developers, and national contractors — 21+ years of filing in the jurisdictions we write about.

Contractors and builders choose Alliance for Union County because the work is done by people who have stood at the counter:

• We confirm the permitting authority for every address.
• We book plumbing inspections with the Health Department.
• We settle sewage and well approvals on unsewered parcels early.
• We clear zoning with the township or city separately.
• We confirm current review and inspection lead times.

Alliance Permitting is a permit documentation and submission company in Ohio. We prepare your paperwork, file it correctly and coordinate with the building department through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Union County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.