The four words that matter to an Ohio board

“Or within an existing townhouse unit.”

Ohio has a great many attached townhouse-style communities held as condominiums or as planned communities with party-wall arrangements. If Section 330 is adopted as drafted, the state building code would affirmatively permit an owner in one of those to create a second, separately numbered dwelling inside their unit, with its own entrance and its own egress path, without a change of occupancy.

Set that against a typical Ohio declaration. Most restrict a unit to use as a single-family residence. Many prohibit subdividing a unit. Many require architectural review for any alteration, and essentially all of them require board approval before an owner cuts a new exterior door.

The code and the covenant would be in direct tension, and the covenant decides. A building code permits; it does not confer a right against a private restriction. But an owner holding a permit issued under a section of the Residential Code of Ohio that says ADUs “shall be permitted” is going to be a difficult conversation. Our Ohio ADUs and modifications page covers where that line sits today.

The municipal layer is already moving

This would arrive on top of city action that has already happened. Columbus legalised ADUs by right in residential districts in November 2025, in an ordinance whose 41-page enrolled exhibit does not contain the words “covenant” or “deed restriction.” Cincinnati permits them in all single-family residential zones. Cleveland Heights has had an ADU ordinance under consideration since July 2026.

Ohio has no statewide ADU statute — no bill in the 136th General Assembly contains the phrase “accessory dwelling” — so the state's contribution, if Section 330 is adopted, would come through the building code rather than through legislation.

What is genuinely useful in the proposal

Two conditions cut in a board's favour and are worth noting.

Owner occupancy. “The owner of a property containing an ADU shall reside in either the primary dwelling unit or the ADU, as of the date of approval.” That excludes the pure investor conversion, which is the scenario boards fear most. Note the qualifier though: as of the date of approval. It is a condition at approval, not a continuing covenant.

One per primary dwelling. No stacking.

And one that does not: the independent egress requirement means a new exterior door or a new path to a common hallway. In an attached building, both are alterations to what an Ohio declaration almost certainly calls a common element or a limited common element — which is precisely where the association's authority is strongest.

What to do now

Read your own use restriction against a unit-interior conversion, not a backyard cottage. Most Ohio boards have thought about the detached ADU. Far fewer have asked whether their documents prevent an owner from creating a separate dwelling inside the unit they already own. “One single-family dwelling per lot” and “no subdivision of a unit” are different clauses with different answers.

Check your architectural review trigger. An interior conversion may not be visible from the street, which is how many association approval requirements are scoped. If the trigger is exterior alteration only, the new door is the trigger — and nothing else is.

Watch the rulemaking, but do not act on it. This is a proposal at the initial stakeholder input stage. It has not been filed with the rule review committee, no public hearing has been held, and it may change or fail. Anyone describing Ohio as having an ADU building-code provision today is wrong.

And one thing that is not being proposed

The same rulemaking packages — 544 pages across the building code and residential code proposals — return zero hits for “facade,” “structural inspection,” “periodic inspection” and “condominium.” Ohio is considering how to legalise a second kitchen. It is not considering whether anyone should inspect the balcony.