# Ohio 2023 NEC rewiring changes for older houses

> Ohio 2023 NEC rewiring changes for older houses: what the Residential Code of Ohio adopted in 2024 and Kentucky's timeline. See what applies to your rewire.

URL: https://confluxcincinnatiknobandtube.com/blog/ohio-2023-nec-and-old-house-rewiring/

Blog, News

Ohio moved its homes to the 2023 National Electrical Code, and Kentucky followed on its own schedule. Here's what changed if you're replacing old wiring, and what didn't.

Last Updated: November 11, 2026

The short answer

Since April 15, 2024, new electrical work in Ohio one- to three-family homes follows the 2023 NEC through the Residential Code of Ohio, with eight Ohio amendments, and IBI inspects your rewire to that edition. The change doesn't order existing knob and tube out, and Kentucky adopted the 2023 NEC on its own timeline.

Every knob and tube job we run at [Conflux Cincinnati Knob and Tube](https://confluxcincinnatiknobandtube.com/) passes inspection under the code where your house is, in Cincinnati, Hamilton County and Northern Kentucky. In Ohio homes, the Ohio 2023 NEC rewiring changes set the standard for that inspection; across the river, Kentucky’s adoption does.

## What did Ohio change, and when?

On April 15, 2024, the Residential Code of Ohio began incorporating the 2023 edition of the National Electrical Code (NFPA 70) for one-, two- and three-family homes, replacing the 2017 edition.

The Ohio Board of Building Standards adopted it as Ohio Administrative Code 4101:8-34-01, with the edition listed in its referenced standards, 4101:8-44-01. Earlier versions of the same rule took effect on January 1, 2013, January 1, 2016 and July 1, 2019.

## Which Ohio amendments matter for your rewire?

Ohio didn’t adopt the 2023 NEC word for word. Its rule lists eight amendments, and three areas matter most when you rewire an old house.

| Area | What Ohio did | What it means for your rewire |
| --- | --- | --- |
| GFCI protection (210.8) | Changed some of the ground-fault requirements | Which new outlets need GFCI follows Ohio’s version, not the national text |
| Surge protection (215.18, 225.42, 230.67) | Required only “where provided” | A service change in an Ohio home doesn’t automatically get a surge protector |
| Sump pumps | Added an exception | A sump pump outlet follows Ohio’s exception rather than the national text |

Our [AFCI and GFCI](https://confluxcincinnatiknobandtube.com/guide/afci-and-gfci-on-knob-and-tube/) guide explains what these devices do on circuits that replace knob and tube.

## What if you own a bigger building?

Then a different code applies. Buildings of four or more units, and buildings that mix apartments with commercial space, fall under the Ohio Building Code. Its referenced standards, OAC 4101:1-35-01, have listed the 2023 NEC since October 15, 2025.

The Ohio Building Code adds one change of its own: an exception in section 210.8(F), on GFCI protection for outdoor outlets, doesn’t expire. Our [two-family and rental rewiring](https://confluxcincinnatiknobandtube.com/two-family-and-rental-rewiring/) page covers how building size changes a job.

## Does the new code make you remove your knob and tube?

No. A code adoption sets the standard for new work. It doesn’t by itself order existing wiring out of your house, and Ohio code doesn’t order existing, unaltered knob and tube removed.

What the code does govern is the work that replaces it. IBI inspects new circuits to the 2023 NEC as Ohio amended it, and the NEC’s article on concealed knob and tube, Article 394, still bars it where insulation surrounds the wires. Our guide [is knob and tube illegal in Ohio](https://confluxcincinnatiknobandtube.com/guide/is-knob-and-tube-illegal-in-ohio/) covers the details.

## Will your service change need an outdoor disconnect?

Maybe; IBI decides. The 2023 NEC includes an outdoor emergency disconnect provision for one- and two-family dwellings, section 230.85, and Ohio’s amendment list leaves it in place.

How it applies when you replace the service on an existing house is the inspector’s call, so we confirm it with IBI before we price a panel or service change. [Fuse box replacement](https://confluxcincinnatiknobandtube.com/fuse-box-replacement/) and our guide to [knob and tube with 200 amp service](https://confluxcincinnatiknobandtube.com/guide/knob-and-tube-and-200-amp-service/) cover panel work.

## What about Northern Kentucky?

Kentucky runs on its own timeline, not Ohio’s. A Kentucky Department of Housing, Buildings and Construction memo dated October 7, 2024 set mandatory enforcement of the 2023 NEC from January 1, 2025.

For one- and two-family dwellings, the memo deferred three sections until July 15, 2026, with the 2017 NEC applying to them until then:

- **210.52(C)**, receptacles at kitchen countertops and work surfaces
- **230.67**, surge protection at the service
- **314.27(C)**, boxes at ceiling fan locations

The memo also delayed certain GFCI items in 210.8 pending a revision of the UL 943 product standard. Our [Covington](https://confluxcincinnatiknobandtube.com/service-areas/covington-ky/) and [Newport](https://confluxcincinnatiknobandtube.com/service-areas/newport-ky/) pages cover who inspects there.

## What does this mean if you’re planning a rewire?

For most owners, the code change shows up in the details, not the decision. New circuits get grounded cable and the protection the current code calls for, and your panel meets the edition in force.

- **Ask which edition applies.** In Cincinnati, IBI inspects to the code the state enforces for your building type.
- **Expect protection on new circuits.** Where AFCI or GFCI applies, we put it in with the work.
- **Keep the permit final.** It’s your record that the work passed under the code in force at the time.

To see how urgent your own situation is, try the [knob and tube assessment](https://confluxcincinnatiknobandtube.com/tools/knob-and-tube-assessment/). To talk through a job, call [(513) 496-2715](tel:+15134962715) or send the form below.

## Questions about this post

### Does my rewire follow the code in force when the permit is issued?

Generally the inspector follows the code the authority enforces for that permit. For Ohio one- to three-family homes that has been the 2023 NEC, as Ohio amended it, since April 15, 2024. If your permit straddles a change, we confirm the edition with IBI or your local inspector.

### Will a fuse panel have to come out because of the 2023 NEC?

Not because of the adoption alone. A code edition governs new work, so it doesn't order your fuse panel out. Replacing the panel is new work, though, and IBI inspects that work to the current edition, including any service rules that apply.

### Do the Kentucky deferrals apply to a house in Covington or Newport?

The Kentucky memo deferred three 2023 NEC sections for one- and two-family dwellings until July 15, 2026, and delayed certain GFCI items pending a product standard revision. We confirm with the Kentucky inspector for your address whether a later notice changed that.

## Keep reading

- [Learn**Is knob and tube wiring illegal in Ohio?** The wiring already in your walls, any new work, and your insurance follow three different sets of rules. Here's where each one draws the line.](https://confluxcincinnatiknobandtube.com/guide/is-knob-and-tube-illegal-in-ohio/)
- [Decision Guide**Can you put a GFCI on knob and tube, and does an AFCI help?** Two devices with confusingly similar names. One protects you from shock, one watches for arcing, and neither turns old wire into new.](https://confluxcincinnatiknobandtube.com/guide/afci-and-gfci-on-knob-and-tube/)
- [Decision Guide**Can you have knob and tube with 200 amp service?** A bigger service feeds your panel. It doesn't change what the old branch circuits can carry, and that's where the confusion starts.](https://confluxcincinnatiknobandtube.com/guide/knob-and-tube-and-200-amp-service/)
- [Learn**How does a Cincinnati electrical permit work for a rewire?** Who issues it, who can pull it, what the inspector looks at before your walls close, and what changes outside the city line.](https://confluxcincinnatiknobandtube.com/guide/cincinnati-electrical-permit/)
- [Decision Guide**How do you hire an electrician for knob and tube work in Ohio?** You can check the credentials in minutes. The harder part is telling whether someone understands old wiring, and a few questions settle that.](https://confluxcincinnatiknobandtube.com/guide/hiring-a-knob-and-tube-electrician-in-ohio/)

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