Short answer
Do I need a permit to build a garage in Anne Arundel County?
Yes. Every garage and carport needs a county building permit, attached or detached, whatever its size. The 150 square foot exemption is for sheds and gazebos only.
| Project | County permit? |
|---|---|
| Attached garage | Yes, filed as a single-family dwelling permit |
| Detached garage or carport | Yes, filed as a residential accessory structure |
| Garage within 3 ft of the house | Yes, treated as attached |
| Wiring, a subpanel or an EV charger circuit | Yes, separate electrical permit |
| Converting a garage to living space | Yes, alteration permit (ADU rules if it becomes a unit) |
| Shed 150 sq ft or less, 10 ft or less tall | Not required outside the Critical Area (see our shed guide) |
1. Attached or detached?
The county's shed exemption doesn't cover garages: garages and carports always need a permit. A garage within 3 feet of the house, or joined to it by an enclosed breezeway 15 feet long or less, counts as part of the house. An attached garage is filed as a single-family dwelling permit and must meet the house setbacks (in R2, for example, 30 feet front, 25 feet rear and 7 feet side). Anything farther away is a detached accessory structure.
2. Where a detached garage can go
On a lot that isn't on the water, an accessory structure can't sit in the front yard, and it must be on the same lot as the house. It also can't be in a setback from a road right-of-way. Setbacks and height limits depend on your zoning district:
| Zone | Side and rear setback | Corner side | Max height | Max lot coverage by structures |
|---|---|---|---|---|
| RA | 15 ft (10 ft if under 8 ft tall) | 40 ft | 45 ft, with larger setbacks over 25 ft | 25% |
| R1 | 15 ft (10 ft if under 8 ft tall) | 40 ft | 45 ft, with larger setbacks over 25 ft | 25% |
| R2 | 7 ft (5 ft if under 8 ft tall) | 20 ft | 25 ft or the house height, whichever is less | 30% |
| R5 | 7 ft (5 ft if under 8 ft tall) | 15 ft | 25 ft or the house height, whichever is less | 40% |
The code also caps an accessory building's floor area at the floor area of the house, though space used to park vehicles isn't counted as floor area. Look up your zoning district on the county map before you design, and confirm corner-lot setbacks with Planning and Zoning: they changed recently in R2. Keep the garage clear of septic systems, wells and easements, which must be shown on the site plan.
3. What the code requires
- Fire separation for attached garages: at least ½-inch gypsum board between the garage and the house and attic, or ⅝-inch Type X if there are rooms above.
- The door into the house: 20-minute rated or 1⅜-inch solid wood, with a self-closer. No openings into bedrooms.
- The floor: non-combustible and sloped toward the overhead door.
- Close to the line: a wall less than 5 feet from a property line needs a 1-hour fire rating.
- Footings: at least 30 inches deep, the county's frost depth.
4. Applying and inspections
File through the county's Land Use Navigator with construction plans at architectural scale, a site plan at engineering scale showing property lines, easements and any well or septic, a Critical Area worksheet and, where it applies, a standard grading plan. Electrical, plumbing, gas and mechanical work need separate permits pulled by licensed trades. A garage usually gets footing, slab, framing and final inspections; the framing inspection needs truss shop drawings, the permit must be active 24 hours before the first inspection, and every trade permit has to pass final before the building final.
5. Fees
| Estimated cost of work | Building permit fee |
|---|---|
| Up to $3,000 | $86 |
| $3,001 to $5,000 | $103 |
| $5,001 to $10,000 | $147 |
| $10,001 to $15,000 | $164 |
| $15,001 to $20,000 | $198 |
| $20,001 to $25,000 | $242 |
| Over $25,000 | $242 plus 1% of the cost above $25,000 |
Add a $43 application fee. A $60,000 detached garage, for example, comes to $242 + $350 + $43 = $635 before trade permits. An electrical permit for a residential alteration is $95 without a service change. Try our permit fee calculator.
6. Near the water or in a floodplain
Within 1,000 feet of tidal water, the Chesapeake Bay Critical Area rules apply. A garage and its driveway count toward your lot coverage limit, which is 15% for most lots and higher for small lots created before December 1, 1985 (for example, 31.25% for lots of 8,001 to 21,780 sq ft). Stay out of the 100-foot shoreline buffer. See our Critical Area guide.
In the floodplain, a garage can sit below the flood protection elevation only if it's used for parking, storage or access, with its floor at or above grade, flood vents and anchoring. Attached garages, two-story garages and those over 300 sq ft also need a recorded agreement not to convert the space. See our flood zone guide.
7. Converting a garage
Turning a garage into living space is an alteration that needs a permit; email the county permit center with your address and plans to confirm what to file. In the floodplain, conversion isn't allowed unless the floor is raised to the flood protection elevation. A garage can also become an accessory dwelling unit: one per lot, with its own entrance, and in a detached building no larger than 800 sq ft or half the house's floor area, whichever is less. See our in-law suite and ADU guide.
8. Inside Annapolis city limits
The City of Annapolis issues its own permits through its Department of Planning and Zoning. A garage needs building, Critical Area, grading and trade review, and the city's target review time for a garage is 7 business days. In the Historic District, you need a certificate of approval from the Historic Preservation Commission before you apply for the building permit. City setbacks vary by district; ask a city planner early. See our Annapolis city permit guide.
