Building permits, zoning and septic rules in Baltimore County, Maryland

Yes. The Department of Permits, Approvals and Inspections (PAI) issues building permits and enforces Baltimore County's building, electrical, plumbing and zoning codes¹. Once a permit is issued, the code official inspects the work during construction and at completion; damage or changes to inspected work before occupancy approval require notice and reinspection². Maryland's owner-performed home-improvement exception does not create a general building-permit exemption for new-home construction or other work, so ask PAI which permits your scope requires⁹. A written permit signed by the Building Engineer is required before any erecting, constructing, repairing, altering or demolishing, and working without one can bring a $1,000 civil penalty¹. The county will not issue a building permit unless sewage and drainage provisions are approved by the Building Engineer and the Director of Environmental Protection and Sustainability, so septic or sewer planning comes first¹. Appropriate use and occupancy certificates are also part of the local enforcement system when applicable to the project¹¹. Baltimore County has adopted the 2021 International Building and Residential Codes with local amendments, and its own electrical and plumbing codes replace the model code's versions of those provisions². Agricultural buildings as the code defines them are excluded from the building-code provisions, but electrical and plumbing permits and other local, state and federal requirements still apply to them².

The Department of Permits, Approvals and Inspections (PAI) is at 111 West Chesapeake Avenue, Towson, MD 21204, phone 410-887-3353¹². PAI is the one-stop office for building, electrical, plumbing and zoning permits, so it's the right first call whether your question is about a permit, an inspection, or whether your lot's zoning allows what you want to build^5,12.

Yes, countywide. Properties are governed by the county's official zoning map, and the Baltimore County Council has sole legislative authority to set or change any property's zoning classification⁵. The Council reviews that map comprehensively every four years and separately considers individual property reclassification requests in between⁵. Lot size depends on the zone. In the rural R.C.5 zone, a lot under one and one-half acres may not be created, density tops out at 0.5 dwelling per acre, and a principal building must sit at least 50 feet from any lot line other than a street line¹³. In the D.R. residential zones, the minimum net lot area per dwelling for qualifying small lots runs from 40,000 square feet in D.R.1 to 6,000 in D.R.5.5¹⁴. Zoning is also where the county's recreational-vehicle rules live: one RV may be stored on a residential lot under specific setback rules, but it can't be lived in while stored there, and as of Bill 20-25 an RV can't be parked on a public road in a residential zone for more than a 24-hour loading window, with a $250-per-day fine for violations⁷.

Baltimore County Ground Water Management administers onsite sewage disposal permits locally under Maryland rules, while the Maryland Department of the Environment coordinates with local authorities^3,4. A permit is required before constructing or altering a septic system, and the system cannot be covered or used until it is inspected and approved^6,15. If an adequate community sewer is economically available, the approving authority may require connection instead, and a septic proposal must conform to the county water and sewerage plan⁶. The county now supplies minimum design criteria rather than the full design, so a new or repaired system needs a licensed designer, licensed installer and site plan³. Only about 17.7% of county soils avoid severe limits for a conventional drain field, making early site evaluation especially valuable¹⁰.

Baltimore County does not allow living in an RV stored on a residential lot; a stored RV must remain licensed, except for a truck camper, and mechanically ready to move⁷. A portable toilet is not a workaround for occupying a new or changed building: without authorization, a portable unit cannot support that occupancy and cannot be used longer than 3 days in a 60-day period¹⁶. Privy plans and location also require approval before a sewage-disposal construction permit is issued¹⁶. We could not confirm a rule specifically allowing a tiny home as a standalone residence, so ask PAI about the parcel's zoning, building permit and occupancy requirements before buying land for that use¹². For a manufactured home, Maryland law bars a county from prohibiting a new manufactured home in a zone that allows single-family homes, but local zoning, utility-connection, site-preparation and permit rules still apply¹⁷.

1. If you plan to divide land, know that a subdivision into three or fewer single-family lots is exempt from the community input meeting and Hearing Officer hearing but still must meet the zoning regulations, and an agricultural subdivision with no new streets is exempt from the development title but not from zoning or septic rules^18,19.
2. Check the parcel's classification on Baltimore County's official zoning map before design; the County Council controls property classifications⁵.
3. Ask Ground Water Management whether the property must connect to available community sewer or can use septic; if septic is allowed, line up the required licensed designer and installer^3,6.
4. Obtain the well permit before drilling if the site needs private water⁸.
5. Submit the building permit to PAI, along with any electrical and plumbing permits the project requires; sealed plans are generally required, though the building official can waive that when the scope does not need review, and fees follow a schedule the County Administrative Officer sets^1,2,20.
6. Complete required inspections during construction and at completion, and obtain the appropriate use and occupancy certificate when applicable^2,11.
7. For development in a special flood hazard area, plan for periodic floodplain inspections; an elevated structure or manufactured home needs an elevation certificate before final inspection and occupancy approval²¹.

Septic and sewer: ask Ground Water Management whether community sewer connection is required before paying for a septic design, and remember that only about 17.7% of county soils avoid severe limits for a conventional drain field^3,6,10. Wells: a private well needs a permit before drilling starts⁸. Flood risk: Baltimore County regulates tidal and nontidal floodplains under a county code that keeps a higher protection standard than the state model ordinance²². Permitted development in a special flood hazard area receives periodic compliance inspections, and an elevated structure or manufactured home needs an elevation certificate before final inspection and occupancy approval²¹. Access: a driveway entering a Maryland state right-of-way requires coordination with the applicable State Highway Administration district office for a permit²³. Taxes: the effective property tax rate is about 1.1%, with a median annual bill near $3,645¹⁰.