Building permits in Montgomery County, Maryland
Find the right authority before you build. Montgomery County permitting follows Maryland law — here is exactly who issues the permit and where to start.
County issues permits
Montgomery County Department of Permitting Services (DPS)
Montgomery County issues building permits through its Department of Permitting Services for properties countywide. Unlike many states, Maryland counties (not cities) serve as the primary permit authority, and municipalities in Montgomery County rely on county permitting.
Open the official permit portal →
DPS offers online application/ePermits, a Residential Fast Track for projects ≤400 sq ft, and free design consultations.
Permit cheat-sheet (Maryland rules)
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | city | Building permit fee set by the city; zoning/use approval also required. | — | Case by case | ADUs require a building permit and local zoning approval. Maryland’s MBPS governs construction; local zoning controls whether an ADU is allowed. Verify with Baltimore DHCD or Annapolis Planning & Zoning. |
| 🪵 Deck / Porch | Conditional | city | Set by the city. | — | Generally allowed | Attached decks and decks over 30 in above grade need a permit. Annapolis publishes deck construction requirements. Exempt: Decks over 30 in above grade generally require a building permit under the IRC (adopted in MD as MBPS). |
| 🧱 Fence / Wall | Conditional | city | — | — | Generally allowed | Most Maryland jurisdictions do not require a building permit for fences, but height and front-yard limits are set locally. Verify with your city. |
| 🛖 Shed / Outbuilding | Conditional | city | — | — | Generally allowed | Detached accessory sheds below the local size threshold are generally exempt. Annapolis publishes shed building requirements. Exempt: Many jurisdictions exempt small detached sheds (commonly under ~120–200 sq ft). |
| 🪜 Basement Finish | Permit required | city | Building permit fee set by the city. | — | Generally allowed | Finishing a basement into habitable space requires permits for egress, framing, electrical, plumbing, and mechanical work. |
| 🚗 Garage / Carport | Permit required | city | Building permit fee set by the city; zoning clearance may be required. | — | Generally allowed | A new attached or detached garage requires a building permit. |
| ☀️ Rooftop Solar PV | Permit required | city | Electrical/structural permit fee set by the city. | — | Generally allowed | Rooftop solar PV requires an electrical and structural permit, reviewed locally. |
| 🌡️ HVAC Replacement | Permit required | city | Mechanical permit fee set by the city. | — | Generally allowed | Furnace, AC, or heat-pump replacement requires a mechanical permit and inspection. |
| 🍳 Kitchen Remodel | Permit required | city | Building permit fee; trade permits billed separately. | — | Generally allowed | A permit is required when relocating plumbing/electrical, moving walls, or changing fixtures. |
| 🛁 Bathroom Remodel | Permit required | city | Building permit fee; trade permits billed separately. | — | Generally allowed | A permit is required when relocating plumbing/electrical, moving walls, or changing fixtures. |
| 🏗️ Room Addition | Permit required | city | Building permit fee based on valuation; zoning and plan review apply. | — | Generally allowed | Room additions require a full building permit, zoning approval, and usually a site plan. |
| 🪟 Window / Door Replacement | Conditional | city | — | — | Generally allowed | Swapping windows or exterior doors in the same opening is generally exempt; enlarging openings requires a permit. |
| 🏘️ Roof Replacement | Permit required | city | Roof-covering permit fee set by the city. | — | Generally allowed | Roof covering replacement is typically permitted. Minor leak repairs may be exempt. |
| 🅿️ Driveway / Parking Pad | Conditional | city | — | — | Generally allowed | A permit may be required where the driveway connects to the street/right-of-way or involves grading/excavation. Verify locally. |
| 🏊 Swimming Pool / Spa | Permit required | city | Building permit fee; barrier fencing required by code. | — | Generally allowed | In-ground and above-ground pools need a permit and barrier fencing per local code. |
| 🧱 Retaining Wall | Conditional | city | — | — | Generally allowed | Height and surcharge determine the threshold. Annapolis requires sheeting/shoring permits for adjacent excavations. Verify with your city. |