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Ohio Building Codes, Permits and Contractor Rules

Here’s every rule from our 50-state guides for Ohio on one page: the residential building code, frost depth, retaining wall permits, the 811 dig law, drainage law, contractor licensing, deposit limits, mechanics lien deadlines, workers’ comp, planting zones and frost dates. Each section links the official source and the full 50-state comparison.

Ohio at a glance

Building code: 2018 IRC (statewide)
Frost depth: Set locally; often 32-42 in.
811 notice: At least 2 working days (not including the day of notice) and not more than 16 calendar days before excavating
Contractors: No statewide requirement (local)
Deposits: No statewide cap
Liens: 60 days from last furnishing (residential)
Workers’ comp: 1+ employees (state fund only)
Drainage rule: Reasonable use
Planting zones: 5b to 7a

Topic	Ohio	Compare
Residential building code	2018 IRC (statewide)	All states
Frost line depth	Set locally; often 32-42 in.	All states
Retaining wall permit	Exempt if not over 4 ft (1219 mm) measured from the bottom of the footing to the top of the wall, unless supporting a surcharge (RCO §102.10, Building item 3).	All states
811 notice before digging	At least 2 working days (not including the day of notice) and not more than 16 calendar days before excavating	All states
Contractor license	No statewide requirement (local)	All states
Deposit limit	No statewide cap	All states
Right to cancel	3 business days, sales made at home	All states
Lien filing deadline	60 days from last furnishing (residential)	All states
Workers’ comp required	1+ employees (state fund only)	All states
Drainage between neighbors	Reasonable use	All states
Planting zones (2023 USDA)	5b to 7a	All states
Frost dates (NOAA)	Last frost mid-Apr (Cincinnati) to late Apr (Toledo); first frost late Oct (Toledo) to early Nov (Cleveland)	All states

Summary for Ohio. Details, exceptions and official sources are in each section below.

Ohio residential building code

Code: Residential Code of Ohio (2018 International Residential Code, first printing, with Ohio amendments; Ohio Adm. Code 4101:8)
How it applies: Statewide, mandatory everywhere
In effect since: July 1, 2019
Code agency: Ohio Board of Building Standards (Department of Commerce)
Who enforces it: Enforced by certified municipal, township or county residential building departments. Where none is certified, owners are not required to submit plans or get inspections, though the code still applies.
Good to know: Ohio's residential code is based on the 2018 IRC and covers one-, two- and three-family homes. In areas without a certified residential building department, no permit or inspection is required, but the work should still meet the code.

Compare building codes in all 50 states

Frost line depth in Ohio

Who sets it: Local building department
Local examples: City of Columbus: 32 in.
City of Cleveland: 42 in. minimum footing depth below finish grade
Lucas County (Toledo area): 36 in. minimum footing depth below finish grade
Typical range: 32-42 in.
Good to know: Mansfield's posted table also shows 36 in. Columbus's figure is from a sheet revised in April 2026.

Frost line depth in every state

Retaining wall permits in Ohio

Permit exemption: Exempt if not over 4 ft (1219 mm) measured from the bottom of the footing to the top of the wall, unless supporting a surcharge (RCO §102.10, Building item 3).
Who decides: Only certified local residential building departments enforce the RCO. According to FEMA, where there is none, compliance is still the builder's responsibility.
Good to know: Height is measured from the bottom of the footing to the top of the wall. Where there's no certified local building department, the builder is still responsible for meeting the code.

Retaining wall permit rules in every state

811 dig law in Ohio

One-call center: OHIO811
Notice before digging: At least 2 working days (not including the day of notice) and not more than 16 calendar days before excavating
Ticket good for: No fixed expiration in ORC 3781.28; marks valid 'as long as visible' (per 811beforeyoudig.com)
Hand-dig zone: Facility width plus 18 in. on each side
Homeowners: Narrow owner exemption: the notice section does not apply to an owner personally excavating their own property unless the work is in a utility easement, a public right-of-way, or an area where utility facilities are known to serve the property (which covers most served homes). 'Excavation' expressly includes hand tools; tilling not over 12 in. is excluded. A hired excavator must always call.
The law: Ohio Rev. Code § 3781.25 et seq.
Good to know: You can give notice no more than 16 calendar days before you dig. A hired excavator must always call.

811 dig laws in every state

Drainage law and stormwater permits in Ohio

Rule: Reasonable use
The rule: Reasonable use: a landowner is liable when a harmful interference with the flow of surface water is unreasonable; disputes are decided case by case under negligence principles.
Leading case: McGlashan v. Spade Rockledge Terrace Condo Development Corp. (as quoted in Novy v. Ferrara). McGlashan v. Spade Rockledge Terrace Condo Dev. Corp., 62 Ohio St.2d 55 (1980); Novy v. Ferrara, 2014-Ohio-1776 (11th Dist.)
What it means for your yard: If your regrading, downspouts or patio unreasonably interfere with how water flows and harm a neighbor, you can be liable; courts weigh the facts case by case.
Construction stormwater permit: Ohio Environmental Protection Agency (Ohio EPA), Division of Surface Water: 1 or more acres of ground disturbance, or part of a larger common plan that will ultimately disturb 1 or more acres: Ohio EPA construction stormwater general permit
State rules below 1 acre: No statewide rule below the 1-acre permit found; check your county and town.
Local rules: Ohio counties and municipalities commonly have their own erosion, sediment and stormwater rules for smaller sites.
Good to know: Ohio judges runoff disputes by whether the interference with water flow was unreasonable. State construction stormwater permits start at 1 acre.

Drainage laws in every state

Contractor licensing in Ohio

Statewide rule: No statewide requirement (local)
Who needs it: No state license for general or residential contractors; local building and health departments regulate residential contractors.
Licensed separately: The Ohio Construction Industry Licensing Board licenses commercial electrical, HVAC, plumbing, hydronics and refrigeration contractors.
Good to know: Your local building department may require a contractor to hold a state commercial trade license.

Contractor license requirements in every state

Contractor deposits and your right to cancel in Ohio

Deposit limit: No statewide cap.
Right to cancel: Home solicitation sales of $25 or more (solicited at the buyer's home or agreed to away from the seller's place of business): may cancel before midnight of the third business day after the transaction; the period doesn't start until the seller provides the required contract and cancellation notice (Ohio Rev. Code §§ 1345.21, 1345.23). Buyer-initiated contacts with in-state sellers and signed emergency waivers are excluded.
Written contract: Home solicitation sales require a written contract with the cancellation statement in 10-point bold near the signature and a duplicate detachable Notice of Cancellation (Ohio Rev. Code § 1345.23). No general home improvement contract statute.
The law: Ohio Rev. Code §§ 1345.21–1345.28 (Home Solicitation Sales Act)
Good to know: Ohio sets no legal deposit limit, but the Attorney General suggests keeping a down payment to around 20% and holding the final payment until the job is done right.

Contractor deposit limits in every state

Mechanics lien deadlines in Ohio

Lien deadline (prime): File the lien affidavit with the county recorder within 60 days after the last labor or materials for a one- or two-family dwelling or residential condo unit (75 days for other projects), and serve the owner within 30 days after filing (ORC 1311.06(B), 1311.07).
Lien deadline (sub/supplier): Same as prime, but on a home construction or purchase contract, no lien if the owner paid the original contractor in full before receiving a copy of the lien affidavit (ORC 1311.011(B)(1)).
Preliminary notice (sub/supplier): Notice of furnishing within 21 days after first furnishing, but only if a notice of commencement was recorded; not required at all for work under a 'home construction contract' (ORC 1311.05(E), 1311.011). Late notice covers only the 21 days before service and after.
Notice of intent: Not required.
Enforce within: Lien lasts 6 years after filing unless an action is brought (ORC 1311.13(C)); the owner can serve notice to commence suit, and the lienholder then has 60 days or the lien is void (ORC 1311.11).
Homeowner rules: For one- and two-family homes and condo units under a home purchase or home construction contract, an owner who paid the original contractor in full before receiving a lien affidavit takes free of all mechanics' liens; if not paid in full, sub liens are capped at the unpaid balance (ORC 1311.011).
The law: ORC Ch. 1311, §§ 1311.01-1311.22 (Mechanics' Liens)
Good to know: Ohio gives only 60 days after your last work to file a lien on a house. Under a home construction or home purchase contract, an owner who paid the original contractor in full before getting a copy of a lien affidavit is protected.

Mechanics lien deadlines in every state

Workers' comp requirements in Ohio

Who must carry it: Employers with 1 or more employees must carry coverage through the Ohio BWC state fund (or be approved to self-insure); independent contractors and subcontractors must cover their own employees (Ohio BWC). BWC is the exclusive provider of workers' comp insurance in Ohio (BWC Annual Report FY2025).
Owners and officers: Corporate officers are employees of the corporation. Coverage is elective for sole proprietors, partners, ministers and officers of a family farm corporation (Ohio BWC); the election is made by written notice to BWC naming the person, and no benefits are paid before BWC receives it (ORC 4123.01).
Subcontractors: Each contractor and subcontractor must carry BWC coverage for its own employees (Ohio BWC). If a contractor or sub hasn't paid its premiums, its workers are treated as employees of the party that hired it (ORC 4123.01). A person working under a construction contract is an employee, not an independent contractor, if at least 10 of 20 listed criteria apply (ORC 4123.01(A)(1)(c)).
Penalties: An injured worker of a non-complying employer can file a claim that the state pays from its surplus fund, and the employer must repay the full award, which the Attorney General can collect; the worker can also sue the employer (ORC 4123.75).
The law: Ohio Revised Code Chapter 4123; ORC 4123.01, 4123.35, 4123.75
State agency: Ohio Bureau of Workers' Compensation (BWC)
Good to know: Ohio coverage comes only from the state fund (BWC), and you need it with one employee. If a sub hasn't paid its BWC premiums, its workers can be treated as yours.

Workers' comp requirements in every state

Planting zones in Ohio

2023 USDA zones: 5b to 7a
Coldest-night range: −15°F to 5°F
Example cities: Columbus: 6b, Cleveland: 7a, Cincinnati: 6b, Toledo: 6b
Local plant advice: Ohio State University Extension
Good to know: Most of Ohio is zone 6. On the 2023 map, the Cincinnati area moved from mainly 6a to 6b.

Planting zones in every state

Frost dates in Ohio

Station	Last spring frost	First fall frost	Frost-free days
Columbus Central Ohio	April 18	October 27	191
Cleveland Lake Erie shore, northeast	April 20	November 3	198
Cincinnati Ohio River valley, southwest (Lunken airport station)	April 16	October 25	190
Toledo Northwest Ohio	April 22	October 24	188

Typical range: Last frost mid-Apr (Cincinnati) to late Apr (Toledo); first frost late Oct (Toledo) to early Nov (Cleveland)
Good to know: These are typical (50%) dates from NOAA's 1991–2020 climate normals, so about half of years still bring a 32°F night after the listed spring date. In Ohio, the last spring frost at the stations listed ranges from mid-April around Cincinnati to late April around Toledo. OSU Extension's Ohio Gardening Calendar bases its planting dates on zone 6a, which it pairs with a May 5–15 last frost and an October 5–15 first frost, more cautious than NOAA's dates for these Ohio stations.
Local frost or planting guide: Ohio State University Extension

Frost dates in every state

Frequently Asked Questions

What building code does Ohio use?

Residential Code of Ohio (2018 International Residential Code, first printing, with Ohio amendments; Ohio Adm. Code 4101:8). It applies as follows: statewide, mandatory everywhere. Your local building department can confirm the edition and amendments for your address.

How deep is the frost line in Ohio?

Frost depth is set by local building departments. Typical local values: 32-42 in.. Footings for houses, additions and attached decks go below it.

How much can a contractor ask for up front in Ohio?

No statewide cap. Cancel rights: Home solicitation sales of $25 or more (solicited at the buyer’s home or agreed to away from the seller’s place of business): may cancel before midnight of the third business day after the transaction; the period doesn’t start until the seller provides the required contract and cancellation notice (Ohio Rev. Code §§ 1345.21, 1345.23). Buyer-initiated contacts with in-state sellers and signed emergency waivers are excluded.

How long does a contractor have to file a mechanics lien in Ohio?

File the lien affidavit with the county recorder within 60 days after the last labor or materials for a one- or two-family dwelling or residential condo unit (75 days for other projects), and serve the owner within 30 days after filing (ORC 1311.06(B), 1311.07). Subcontractors and suppliers may have different notice rules; see the section above.

What planting zone is Ohio?

On the 2023 USDA map, Ohio runs from zone 5b to 7a. Examples: Columbus 6b, Cleveland 7a, Cincinnati 6b. Enter your ZIP on the USDA map for your exact zone.

Do contractors need workers' comp in Ohio?

Employers with 1 or more employees must carry coverage through the Ohio BWC state fund (or be approved to self-insure); independent contractors and subcontractors must cover their own employees (Ohio BWC). BWC is the exclusive provider of workers’ comp insurance in Ohio (BWC Annual Report FY2025). Owner exemptions and subcontractor rules are in the workers’ comp section above.

When is the last frost in Ohio?

At the NOAA stations we list: Last frost mid-Apr (Cincinnati) to late Apr (Toledo); first frost late Oct (Toledo) to early Nov (Cleveland). These are typical (50%) dates from the 1991–2020 climate normals, so about half of years still bring a 32°F night after the spring date.

This page is general information, not legal or tax advice. Rules change; the agencies and statutes linked above have the final word.

Ohio in each 50-state guide: Frost line depth · 811 dig laws · Retaining wall permits · Contractor licensing · Contractor deposit limits · Building codes · Planting zones · Mechanics lien deadlines · Workers' comp · Frost dates · Drainage laws · Noxious weed laws · Rainfall and snowfall · Landscaper pay · Pesticide applicator licensing · Landscaping sales tax · All state guides

Soil: Ohio’s most common soils, state soil, and how much ground is wet, clayey or shallow to bedrock by county. Ohio soil types

Last checked October 31 and November 1, 2026 against official state and local sources for this state. Rules change; your state agency or local building department has the final word. Spot something out of date? Email info@muthlerlandscaping.com and we’ll fix it.

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