Building permits, zoning and land rules in Delaware County, Ohio

Delaware County Building Safety requires plan approval and a building permit for new homes, additions, accessory structures, decks and pools in unincorporated areas¹. Covered work cannot start before the building department with jurisdiction approves the required plans¹³. Delaware County incorporates Ohio's adopted building codes: covered residential dwellings must follow the latest adopted Residential Code of Ohio, and other covered structures must follow the latest Ohio Building Code¹⁴.

A one-story detached shed or playhouse of no more than 200 square feet needs no building approval, and neither does a fence up to 7 feet high; replacing a furnace or water heater does need approval¹⁵. A pole building beyond the code's prescriptive limits needs a sealed engineered plan¹. In county zoning areas, an agricultural exemption requires exclusive agricultural use, a scaled site plan and acceptance by a zoning official¹⁶.

For a change-of-occupancy application under county Code Compliance jurisdiction, each applicable trade needs inspection even without alterations; the final Certificate of Occupancy follows completion of all inspections¹⁷.

For unincorporated land, contact Delaware County Building Safety at 1610 State Route 521, (740) 833-2200 or building@co.delaware.oh.us^1,6. Email residential applications as PDFs to residential@co.delaware.oh.us; the public portal shows permit status 72 hours after a complete submission⁶. A new-house packet needs a certified house number, zoning approval, any required drainage approval and a septic permit without public sewer; incomplete packets are not accepted¹.

Inside Powell, the city issues building permits, while household septic services remain with the Delaware Public Health District^18,19. Columbus, primarily in Franklin County but extending into Delaware County, requires city building permits; ask Columbus Public Health to confirm septic jurisdiction for the address^20,21.

An owner may obtain the county building permit and perform or directly supervise work with a notarized affidavit; licensed contractors must obtain their own permits where applicable, and the owner remains responsible for work under the owner's permit¹².

The Delaware Public Health District handles household sewage systems serving 1-, 2- or 3-family dwellings where sanitary sewer connection is not feasible⁴. Every lot needs a soil evaluation, scaled system design and house floor plan; a sanitarian reviews the documents and visits before issuance of the signed installation permit⁵. The 2026 fee schedule lists $250 for a permit-related site review, $250 for a design review and $200 per lot for a lot feasibility review; a new private water system permit is $474 plus a lab fee²². Confirm the full installation-permit total with the district, since the schedule also lists separate permit charges²².

The installation permit lasts 1 year; operating permits are required for the system's lifetime, with terms of 1 or 5 years depending on system type⁵. The district reviews potential parcels and designs and inspects installation⁴. Request the final inspection at least 24 hours before completion, and leave the system uncovered until inspection approval⁸. Semi-public systems have separate capacity limits and annual operating inspections; scope shared or nonresidential projects with the district⁴.

The soil survey rates 0% of Delaware County soils “not limited” for conventional drain fields; that does not make septic impossible, but makes a site evaluation essential before choosing the house location or system type^5,23.

In Marlboro, Radnor and Thompson townships, an RV or mobile home may be occupied only while a house is being built, for up to 18 months from the zoning-permit date¹⁰. The temporary unit must be removed within 30 days after that period ends or within 30 days after the occupancy permit, whichever comes first¹⁰. Guests may stay in a camper or motor home for no more than 30 days in a calendar year¹⁰.

A tiny house under 950 square feet cannot be the primary home on a Farm Residence lot in those county-zoned townships¹⁰. We could not confirm a countywide rule for private-parcel RV living or tiny homes; ask the zoning officer for the parcel's jurisdiction about use, duration, dwelling size and setbacks^2,24. Within the Delaware Public Health District, on-site sewage requires installation and operating permits, and central sewer connection is required when sewer becomes available⁴. A manufactured home generally cannot be occupied until the state inspector issues its inspection seal²⁵.

1. Identify the parcel's zoning jurisdiction and confirm the proposed use, setbacks and required certificate with that zoning officer^2,24.
2. If public sewer is not feasible, obtain the soil evaluation, scaled sewage-system design and house floor plan required for health-district review⁵.
3. Obtain the septic installation permit, and obtain a private-water-system permit from the board of health before well work begins^5,11.
4. For footprint-changing construction on an unincorporated parcel of 1 acre or more outside a platted subdivision, obtain the Drainage Review Permit before applying for the building permit⁹.
5. Stake the site, post the address and obtain the applicable zoning certificate³.
6. Email the complete residential package to Building Safety at residential@co.delaware.oh.us; an owner-builder must also complete the notarized affidavit and accept responsibility for the work^6,12.
7. Keep the septic system uncovered until its final inspection is approved, and satisfy drainage mitigation before Building Safety schedules the final occupancy inspection^8,9.

Ask the health district whether the lot has enough suitable area for a sewage system before buying; the district offers lot-feasibility review and inspects proposed parcels⁴. Determine whether sanitary sewer is available too: on-site systems are intended for places where connection is not feasible, and the permit application requires abandonment of the system and connection to central sewer when service later becomes available^4,8.

If you plan to split land, creating a parcel under 5 acres generally falls within Ohio's subdivision rules²⁶. A Delaware County no-plat split needs review from zoning, the health department and the County Engineer or state transportation agency where applicable²⁷. Ask Building Safety about floodplain review because the residential application asks whether the property has floodplain¹.

Farmland averages about $9,771 an acre, the nearest city of 100,000 or more is about 23 straight-line miles from the county center, and density is about 523 people per square mile²³. The median property-tax bill is $6,896, with an effective rate of 1.6%²³.