Building permits, zoning and land rules in Washington County, Maryland

On property outside Boonsboro, Clear Spring, Hagerstown, Hancock, Keedysville, Sharpsburg and Williamsport, Washington County requires a building permit for construction, enlargement, alteration, repair, movement, demolition, occupancy changes, and regulated electrical, gas, mechanical or plumbing work¹. The county has adopted the 2021 Maryland Building Performance Standards, with county modifications and local amendments to the 2021 building, residential and energy codes⁹. County materials specifically include decks and sheds over 400 square feet in the building-permit process¹⁰. A qualifying agricultural structure that is tied to an agricultural operation and is neither occupied by people nor open to the public may avoid a building permit, but it still needs an agricultural structure certificate and must meet district setbacks².

Washington County Permits & Inspections handles county-administered building permits from 747 Northern Ave in Hagerstown and can be reached at 240-313-2460¹¹. The county building excise tax effective July 1, 2026 is $1.75 per square foot for new residential construction and $0.88 per square foot for residential additions and alterations¹¹. An owner may act as the responsible general contractor of record, but must not contract with someone else to perform, manage, oversee or supervise the permitted work without notifying the building office and adding the contractor's name and license number⁶. A new home or addition requires at least four inspections, each requested with at least 24 hours' notice¹². For county-administered projects, construction and final inspections must be complete before the Use and Occupancy Certificate is issued, and a private well's water samples must have Health Department approval¹².

Washington County's zoning ordinance and official zoning map cover land outside incorporated municipalities, and Planning & Zoning maintains the map and its amendments². Ask that office for the parcel's district before relying on a use, setback, lot-size or height assumption¹³. For example, the RB Rural Business floating zone has a 40,000-square-foot minimum lot and district-specific setbacks². Its normal structure height is 35 feet, while a qualifying building in an Agricultural, Residential or Business district may reach three stories and 45 feet only if each side yard increases by one-half foot for every extra foot above the normal limit². A subdivision lot in unincorporated Washington County cannot be sold or built on until the Planning Commission approves the plat and the Clerk of the Circuit Court records it¹⁴.

The Washington County Health Department administers onsite sewage programs under delegated state authority³. A septic permit or site-evaluation application may be needed during building review, and building approval may follow or occur alongside the well permit, septic permit and recorded agreements¹⁵. No part of a new onsite sewage system may be covered or used until the Health Department or an approved third party inspects and approves it⁵. That installation rule does not establish a mandatory septic inspection for every property sale, which we could not confirm. A permit is also required to construct any well in Maryland⁴. Septic serves sites without public collection, but the approving authority may require a sewer connection where community sewer is adequate and economically available^3,5. Only about 40.1% of county soils avoid a severe limitation rating for conventional drain fields, so complete the site evaluation before treating a homesite as buildable⁸.

A recreational travel vehicle cannot be used for living purposes on land governed by the Washington County zoning ordinance unless it is in a bona fide recreational camping area². An owner may store an RV in a garage, accessory building, rear yard, side yard or driveway, subject to the ordinance's placement rules². We could not confirm a specific county rule for occupying a tiny home or a general minimum dwelling size, so ask Planning & Zoning about the proposed structure and parcel before buying¹³. Maryland allows a qualifying manufactured home in a zone permitting single-family residential use once it is converted to real property, but county zoning, construction, site preparation, utility and permit requirements still apply¹⁶. A qualifying accessory dwelling unit is allowed in the listed county zoning districts, with its size capped at 1,200 square feet or 75% of the primary residence's gross floor area, whichever is less⁷.

1. Confirm the zoning district, permitted dwelling type, setbacks, height and any subdivision-plat issue with Planning & Zoning^2,13.
2. Have the Health Department determine the onsite sewage and well approvals needed for the building review^3,15.
3. Obtain a county floodplain permit before any work that is wholly or partly in contact with a flood-hazard area¹⁷.
4. Submit the plot plan, construction drawings and building-permit application to Permits & Inspections^1,11.
5. Apply for a county-road entrance with the building permit, or contact the Maryland State Highway Administration for access to a state route^10,18.
6. Complete building and septic installation inspections, then obtain the Use and Occupancy Certificate before moving in^5,12.

Before closing, confirm the zoning map and any subdivision status with Planning & Zoning, because district rules determine uses, setbacks and height^2,13. Check the proposed house, driveway and septic area against flood hazards; unincorporated-county development touching a flood-hazard area needs a county floodplain permit before work begins¹⁷. Washington County has about 77.9% of its land at a slope of 15% or less and about 51.1% forest cover, but those countywide figures do not establish that a particular lot is buildable⁸. Farmland averages about $8,668 per acre, the typical home value is about $335,497, and the median property-tax bill is about $2,444 per year⁸. Finally, determine whether access is from a county road or state route, because the responsible entrance-permit authority changes^10,18.