ADUs are allowed in Bel AirTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Bel Air, MD
Is your property eligible for an ADU?
# of Properties
3,930
Owner-occupied
64%
Zoning districts
10
Avg Home Value
$280,288
Median Lot Size
0.14 acres
Avg Income
$88,864
Residential Types:
3,930 housing units
Single Family
9%
Apts (4+ units)
1%
Other
91%
Zoning Districts:
4,887 parcels · 10 districts
R1
30%(1,489)
R3
28%(1,348)
R2
27%(1,322)
B3
6%(269)
Other
9%(459)
ADU Rules
What can you build in Bel Air, MD?
Bel Air, MD follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: By Right
- –Detached ADU: By Right
Interior / Attached ADU Size Limits
- –Maximum ADU size is limited by the overall accessory-use cap: up to 50% of the principal dwelling’s habitable space, but never less than 480 sq ft; this total is shared with all other accessory uses/structures.
Detached ADU Size Limits
- –Maximum size is 50% of the principal dwelling’s habitable space, with at least 480 sq ft allowed; this cap is shared with all accessory structures on the lot.
Owner Occupancy
- –Principal dwelling must be owner-occupied; ADU ends if vacant 12+ months.
Parking
- –No ADU parking minimum/maximum stated; off-site/satellite parking allowed with at least one space on-site or adjoining if used; waivers/reductions may be granted by the Board of Appeals; for uses not specified, Zoning Administrator determines requirements based on the most similar use.
Rental Restrictions
- –Short-term rentals prohibited; ADUs must be occupied for more than 28 days. May only be rented to extended family of the owner or a caregiver (unrelated tenants not allowed).
ADU State Law
What can you build in Maryland?
- –Local-law mandate: By Oct 1, 2026, each legislative body must adopt a local law authorizing ADUs under this section.
- –Local zoning mostly remains: The subtitle generally does not alter local zoning power except as provided, but locals must establish policies that further the subtitle's intent.
- –Definition-based size cap: An ADU must be ≤ 75% of the size of the primary SF detached dwelling and subordinate in use; ADUs may be detached or attached.
- –Density/growth limits: ADUs must be excluded from density calculations and from measures limiting residential growth that pertain to the lot/parcel/tract.
- –Setbacks: Local law cannot set side/rear setbacks that exceed existing accessory-structure setbacks.
- –Parking: If a jurisdiction adds off-street parking requirements, it must consider specified factors and provide a waiver process, and must complete a parking study before adopting such requirements.
- –Alley access option: Local law may prohibit converting an accessory structure to an ADU if only vehicular access is from an alley.
- –Codes/adequate facilities: Local law must provide for ADU construction meeting public health/safety/welfare standards, including building codes and adequate public facilities provisions.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
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ADU rules in other Maryland municipalities
Rules change at the town line. Check the municipality your property is actually in.
Harford County