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

Montgomery County Building Regulations requires building permits for covered construction on unincorporated land and in municipalities served by the department^1,4. New construction, additions, alterations, basement finishing, garage conversions, and decks fall within the county’s enforcement scope; construction may begin only after the building permit is issued^1,7. Single-story detached residential sheds of no more than 200 square feet may be exempt from building permits, but must still meet residential code standards¹. A zoning certificate declaring the building’s agricultural use qualifies it for the applicable Ohio building-code exemption⁸.

County-regulated construction needs rough inspections before work is covered and final inspections after completion; footings, slabs, and gas or electric trenches need inspection before concrete or backfill⁷. Inspectors visit at various construction stages, and approved permit documents must be on site during each inspection^1,7. Projects near a FEMA-designated floodplain may also require a Floodplain Construction Permit⁶.

Montgomery County Building Regulations Division handles building permits and inspections in all county townships and contracted cities and villages¹. The office is at 451 W. Third St., 10th Floor, Dayton, OH 45422; call (937) 225-4622 or email build@mcohio.org⁹. Springboro and Carlisle, cities mainly in Warren County that extend into Montgomery County, have local building-permit services; Carlisle contracts with Springboro for building plan review and inspections^10,11. Household septic permitting for Montgomery County properties remains with Public Health - Dayton & Montgomery County³.

Homeowners working on their own property in Montgomery County’s enforcement jurisdiction need not register as contractors, but required building permits and inspections still apply; Dayton, Centerville, Kettering and other jurisdictions may have different contractor-registration requirements^1,7. Obtain required zoning and septic approvals before filing the county building application⁷. Effective July 1, 2026, canceling a county inspection after 2:00 p.m. the preceding day carries a $125 fee; the county publishes a fee schedule for other charges¹².

Public Health - Dayton & Montgomery County issues household septic permits and oversees maintenance under state and local rules, and registers the contractors who may work in the county³. Installing, replacing, or altering a Montgomery County household septic system requires a septic permit; tank cleaning and minor repairs do not³. Homeowners also need a separate household sewage treatment system operation permit³. For a new home, arrange the health-board site review, soil evaluation, and system design before applying for the installation permit¹³. Call 937-225-4428 or visit the Reibold Building at 117 S Main Street in Dayton³.

USDA’s countywide soil measure rates 0% of Montgomery County soils “not limited” for conventional drain fields; that signals the need for a site evaluation or potentially an engineered system, rather than proving septic is impossible on a parcel¹⁴. Only systems meeting specified criteria need annual inspection by a registered service provider, and the vast majority of systems do not; NPDES systems also require annual effluent sampling¹⁵. Where an accessible, available public sewer meets Ohio’s connection conditions, connection is required instead of private sewage disposal¹⁶.

We could not confirm a countywide rule allowing or prohibiting full-time RV living on private land in Montgomery County. The Ohio campground rule governs RVs placed in licensed campgrounds and temporary campgrounds, not ordinary private-parcel occupancy, so it does not answer whether an RV may be used as a residence on a particular township parcel¹⁷. Ask the township zoning office how it treats RV storage, temporary occupancy during construction, utility connections, and camping before buying land for that plan¹.

We also could not confirm a single Montgomery County rule for tiny-home occupancy or minimum dwelling size. A tiny home built as a dwelling still faces the applicable local zoning classification and the building-permit process^1,4. A finished dwelling under Montgomery County Building Regulations requires a Certificate of Occupancy after required inspections pass; continuing an existing legally approved use without changing that use does not require a new certificate⁶. A zoning certificate of occupancy does not replace the building certificate¹. A manufactured home follows a separate state inspection path and generally cannot be occupied until an inspector issues the inspection seal, subject to the temporary-occupancy exception and local siting rules¹⁸.

1. Identify the township, city, or village and obtain the zoning permit from that jurisdiction before the county building application^1,7.

1. Ask Public Health or the local utility whether public sewer and water serve the lot and what tap-in authorization is required¹⁹. An accessible and available sanitary sewer must be used when Ohio's connection conditions are met¹⁶.

1. For private septic, complete the site review, soil evaluation, and system design, then obtain the permit from Public Health - Dayton & Montgomery County^3,13.

1. For a private well, obtain the permit required for a new, upgraded, altered, or abandoned-and-sealed private water system; minor repairs do not require one, but well abandonment requires inspection and an inspection permit^3,5.

1. Submit the application, plans, fees, and prior approvals to the correct building department, and wait for the issued permit before construction begins⁷.

1. Schedule rough inspections before covering work and final inspections after completion, then obtain the Certificate of Occupancy before using the finished dwelling¹.

Confirm the local jurisdiction first, then obtain its zoning map and resolution because zoning permits come from the township, city, or village where the property is located¹. Verify access and ask the County Planning Commission whether a proposed lot split or subdivision triggers review; the commission handles subdivisions in unincorporated townships, and its thoroughfare plan sets subdivision standards for intersections and driveways²⁰. Check whether the house site is near a FEMA-designated floodplain because development there may require a Floodplain Construction Permit⁶.

Before choosing a house site, obtain the septic site review and soil evaluation required for a new system¹³. Ask Public Health or the local purveyor about water, sewer, and tap-in authorization, and confirm whether sewer connection is required^16,19. New, upgraded, altered, and abandoned-and-sealed private water systems require permits, while minor repairs do not⁵. Finally, check carrying costs: the effective property-tax rate is about 1.8%, and the median annual property-tax bill is about $2,975¹⁴.