--- title: "Baltimore County Building Permits: What Needs One | TBG" description: "Which home projects need a Baltimore County permit: decks, fences, sheds, basements, additions and retaining walls, plus licensing, historic and floodplain rules." url: https://thebrettgroup.com/guides/baltimore-county-building-permits/ last_updated: 2026-10-14 --- [TBG](https://thebrettgroup.com/) / [Home Remodeling](https://thebrettgroup.com/remodeling/) / Baltimore County permits Local guide · Baltimore County · October 2026 # Do you need a building permit in Baltimore County? Baltimore County sets clear size limits for decks, fences and sheds, and stricter rules for historic, floodplain and waterfront lots. Here is what needs a permit, who can pull it, and how the county process works. Get matched with a builder who knows this - **16 in**: Decks higher than this and over 120 sq ft need a permit - **42 in**: Fences this tall or taller need a permit - **120 sq ft**: Sheds larger than this need a permit - **Any size**: Historic, floodplain and Critical Area lots | Project | Baltimore County permit? | | --- | --- | | Deck more than 16 in above grade and over 120 sq ft | Yes | | Fence 42 in or taller | Yes | | Shed or accessory building over 120 sq ft | Yes | | Retaining wall over 3 ft | Yes | | Basement finishing with structural, bedroom or trade work | Yes | | Addition, structural change, new bedroom or kitchen, enclosed porch | Yes | | Plumbing, gas or electrical work | Yes, trade permit | | Siding and roof repair | Not required, unless the house is historic or a landmark | | Smaller decks, fences and sheds on a historic, floodplain or Critical Area lot | Yes, at any size | ## 1. Who issues permits Baltimore County's Department of Permits, Approvals and Inspections (PAI) issues building, plumbing and electrical permits for the whole county, including Towson, Catonsville, Arbutus and every other unincorporated community. Its office is in the County Office Building at 111 West Chesapeake Avenue in Towson, open weekdays 8:30 to 4:30 (410-887-3900). Since November 2021, applications are filed online, and the county answers "do I need a permit?" questions at 410-887-3953. ## 2. Decks, fences, sheds and walls - **Decks** need a permit when they are more than 16 inches above grade and larger than 120 square feet. Under 600 square feet, a site plan is enough; 600 square feet or more needs construction plans. - **Fences** need a permit at 42 inches or taller, and can't be built in access easements. - **Sheds and accessory buildings** over 120 square feet need a permit. They go in the rear yard, at least 2.5 feet from side and rear lot lines, no taller than 15 feet, with frost footings over 400 square feet. - **Retaining walls** over 3 feet need a permit, with extra documents at 4 feet and up. ## 3. Basements, additions and remodels Finishing a basement needs a permit when you move a bearing wall, make structural changes, add a bedroom, excavate, or run any plumbing, gas or electrical work. Additions, structural alterations, a new bedroom or kitchen, and enclosing a porch or deck all need a building permit. Sealed plans from a Maryland-licensed design professional are required for additions of 600 square feet or more, new bedrooms, second-floor additions and structural work, along with a 2021 energy code form. ## 4. Who can pull the permit Contractors need a Maryland Home Improvement Commission license. Baltimore County also licenses its own plumbers and gasfitters: only a Baltimore County-licensed plumbing or gasfitting contractor can apply for those permits. State-licensed master electricians must register with the county; homeowners making minor wiring repairs in their own home are exempt from the license requirement. ## 5. Historic, floodplain and waterfront lots Properties on the county Landmarks List or in one of its historic districts, such as Lutherville, Relay, Sudbrook Park or Glyndon, need a Certificate of Appropriateness from the Landmarks Preservation Commission for exterior changes, and a permit even for work that normally wouldn't need one. The Commission meets the second Thursday of most months. In the floodplain, county rules (Bill 6-24) require two elevation certificates by a licensed surveyor before a permit is closed. Within 1,000 feet of tidal water, Chesapeake Bay Critical Area limits on lot coverage and tree clearing apply. Near Martin State Airport, an airport zoning permit may also be needed. ## 6. Codes and inspections Baltimore County builds to the 2021 International Residential, Building and Energy Codes and the 2023 National Electrical Code. Schedule inspections through your online account by 2 p.m. the business day before. Ask PAI for the current fee when you apply. Inside Anne Arundel County, see our [Anne Arundel permit guide](https://thebrettgroup.com/guides/permits-anne-arundel-annapolis/); in Howard County, our [Howard County guide](https://thebrettgroup.com/guides/howard-county-building-permits/). ## Where this comes up most [Towson →](https://thebrettgroup.com/remodeling/towson/) · [Catonsville →](https://thebrettgroup.com/remodeling/catonsville/) · [Arbutus →](https://thebrettgroup.com/remodeling/arbutus/) ## Projects we match - [Additions](https://thebrettgroup.com/remodeling/additions/anne-arundel/): Bump-outs, second stories and in-law suites. - [Basement finishing](https://thebrettgroup.com/remodeling/basement/anne-arundel/): Living space, egress, bathrooms and waterproofing. - [Decks & exteriors](https://thebrettgroup.com/remodeling/decks-exteriors/anne-arundel/): Decks, porches, siding, windows and roofing. ## Common questions ### Do I need a permit for a deck in Baltimore County? Yes if the deck is more than 16 inches above grade and larger than 120 square feet, or at any size on a historic, floodplain or Critical Area property. ### How tall can a fence be without a permit in Baltimore County? Under 42 inches. Fences 42 inches or taller need a permit, and any fence on a historic, floodplain or Critical Area lot needs one. ### Can a homeowner do their own plumbing in Baltimore County? Plumbing and gas permits can only be pulled by a Baltimore County-licensed plumbing or gasfitting contractor. Homeowners are exempt from electrical licensing only for minor repairs in their own home. ### Where do I apply for a building permit in Baltimore County? Online, through the Department of Permits, Approvals and Inspections (PAI). Its office is at 111 West Chesapeake Avenue in Towson, 410-887-3900. ## Official sources [Baltimore County PAI: Permit applications](https://www.baltimorecountymd.gov/departments/pai/application) · [PAI: Deck permits](https://www.baltimorecountymd.gov/departments/pai/application/deck) · [PAI: Fence permits](https://www.baltimorecountymd.gov/departments/pai/application/fence) · [PAI: Accessory structures](https://www.baltimorecountymd.gov/departments/pai/application/accessory-structure) · [PAI: Basements](https://www.baltimorecountymd.gov/departments/pai/application/basement) · [PAI: Additions and alterations](https://www.baltimorecountymd.gov/departments/pai/application/addition-alteration-modification) · [PAI: Plumbing licensing](https://www.baltimorecountymd.gov/departments/pai/plumbing/licensing) · [PAI: Electrical licensing](https://www.baltimorecountymd.gov/departments/pai/electrical-inspections/licensing) · [PAI: Floodplain](https://baltimorecountymd.gov/departments/pai/floodplain) · [Baltimore County: Historic review](https://www.baltimorecountymd.gov/departments/planning/historic-preservation/historic-review) · [PAI: Schedule an inspection](https://www.baltimorecountymd.gov/departments/pai/schedule-inspection) This guide is general information, not legal or engineering advice. Rules and maps change; confirm the requirements for your property with the permit office before you design or sign a contract. ## More local guides [Renovating or adding on in a flood zone in Anne Arundel County](https://thebrettgroup.com/guides/flood-zone-renovation-anne-arundel/) · [Building or adding on near the water: the Critical Area explained](https://thebrettgroup.com/guides/building-near-the-water-critical-area/) · [Remodeling ideas for Anne Arundel County's most common house types](https://thebrettgroup.com/guides/remodeling-anne-arundel-house-types/) · [Materials that hold up near the Chesapeake](https://thebrettgroup.com/guides/chesapeake-coastal-building-materials/) · [Septic upgrades and Bay Restoration Fund grants in Anne Arundel County](https://thebrettgroup.com/guides/septic-upgrades-bay-restoration-fund/) · [Deck permits in Anne Arundel County](https://thebrettgroup.com/guides/deck-permits-anne-arundel/) · [In-law suites and accessory dwelling units in Anne Arundel County](https://thebrettgroup.com/guides/in-law-suites-adu-anne-arundel/) · [Energy rebates for Maryland home remodels in 2026](https://thebrettgroup.com/guides/energy-rebates-maryland-remodel/) · [Renovating a home in the Annapolis historic district](https://thebrettgroup.com/guides/annapolis-historic-district-renovation/) · [Do you need a permit to finish a basement in Anne Arundel County?](https://thebrettgroup.com/guides/basement-finishing-permit-anne-arundel/) · [Do you need a permit for a kitchen remodel in Anne Arundel County?](https://thebrettgroup.com/guides/kitchen-remodel-permit-anne-arundel/) · [Do you need a permit for a bathroom remodel in Anne Arundel County?](https://thebrettgroup.com/guides/bathroom-remodel-permit-anne-arundel/) · [Do you need a permit for a fence in Anne Arundel County?](https://thebrettgroup.com/guides/fence-permit-anne-arundel/) · [Do you need a permit for a shed or detached garage in Anne Arundel County?](https://thebrettgroup.com/guides/shed-permit-anne-arundel/) · [Do you need a permit for a pool or hot tub in Anne Arundel County?](https://thebrettgroup.com/guides/pool-permit-anne-arundel/) · [Do you need a permit to replace a roof, siding or windows in Anne Arundel County?](https://thebrettgroup.com/guides/roof-siding-permit-anne-arundel/) · [Permits for a home addition in Anne Arundel County](https://thebrettgroup.com/guides/home-addition-permit-anne-arundel/) · [Demolition permits in Anne Arundel County](https://thebrettgroup.com/guides/demolition-permit-anne-arundel/) · [How to get a building permit in Anne Arundel County](https://thebrettgroup.com/guides/how-to-get-building-permit-anne-arundel/) · [Buying or selling a house with unpermitted work in Anne Arundel County](https://thebrettgroup.com/guides/unpermitted-work-buying-selling-anne-arundel/) · [Building permits in the City of Annapolis](https://thebrettgroup.com/guides/annapolis-city-building-permits/) · [Anne Arundel County permit fee calculator](https://thebrettgroup.com/guides/permit-fee-calculator-anne-arundel/) · [Do you need a building permit in Howard County?](https://thebrettgroup.com/guides/howard-county-building-permits/) · [Remodeling permits in Anne Arundel County and Annapolis](https://thebrettgroup.com/guides/permits-anne-arundel-annapolis/) · [How to hire a home improvement contractor in Maryland](https://thebrettgroup.com/guides/hiring-a-contractor-maryland/)