ADU Pass
Worcester County
ADU Pass helps homeowners in Worcester County, Maryland navigate the permit paperwork for building an accessory dwelling unit. We cover 8 cities and 15 ZIP codes in this county.
Map
County ADU details
County ADU ordinance
Worcester County Zoning Section ZS 1-322 conditionally permits one accessory dwelling unit per lot in the A-1 Agricultural, A-2 Resource Conservation, E-1 Estate, R-1 Rural Residential, R-2 Suburban Residential, R-3 Multifamily Residential, and V Village zoning districts, in addition to one primary single-family detached dwelling. The ADU may be (a) attached/integrated into the primary dwelling, (b) a converted portion of a permitted accessory structure such as a garage or carriage house, or (c) detached. Owner-occupancy of either the primary or the accessory unit is required, with the Department of Review and Permitting (DRP) authorized to require an owner-occupancy affidavit at permit issuance and on resale. The accessory unit may not be subdivided or sold separately from the primary dwelling. Detached ADUs are capped at 900 square feet of gross floor area on parcels under 1 acre and at 1,000 square feet on parcels of 1 acre or more; the ADU footprint must observe the accessory-structure setbacks of the underlying district (typically 10 ft side, 15 ft rear in residential districts, and reduced setbacks in the Estate and Agricultural districts). One additional off-street parking space is required for the ADU beyond what the primary dwelling needs. Properties on private septic require Worcester County Environmental Programs sign-off that the existing or upgraded on-site sewage disposal system can support the added bedroom count under the Maryland Department of the Environment Bay Restoration Fund rules. In the Atlantic Coastal Bays Critical Area Overlay (Section ZS 1-116 et seq.), the ADU counts toward the per-acre density of the underlying Critical Area classification (IDA, LDA, or RCA), and detached ADUs in the RCA classification are limited to one per 20 acres absent a growth-allocation award. Worcester County is in the process of amending Section ZS 1-322 to align with the Maryland HB 1466 / SB 891 (Accessory Dwelling Units Act) statutory floor by the statewide 2026-10-01 deadline.
County assessor
Assessment policy: SDAT assesses property at fair market value using the cost, sales, and income approaches. Each property is reviewed on a triennial cycle (every three years); the Worcester County reassessment area map identifies which cycle group a parcel sits in. New construction and additions, including accessory dwelling units, trigger an interim supplemental reassessment in the year of completion under the cost approach. Maryland's Homestead Tax Credit caps the year-over-year increase in the TAXABLE assessment on an owner-occupied principal residence, but the credit applies only to the primary dwelling - added accessory-dwelling square footage is taxed at its full assessed value without the homestead cap. Worcester County is also home to a substantial seasonal/second-home stock (Ocean City and the coastal-bay shoreline), and second-home owners are NOT eligible for the Homestead Credit on the Worcester parcel.
County overlays (4)
- Atlantic Coastal Bays Critical Area Overlay — A detached ADU on an RCA-classified parcel may be limited to one per 20 acres absent a growth-allocation award from the County Commissioners; LDA-classified parcels are capped at 15% lot coverage with offsets required for new impervious surface; IDA parcels face the most permissive density but still require buffer plantings and stormwater management. Worcester County, like the Chesapeake Bay counties, is required to maintain records of all Critical Area accessory-dwelling building permits and to report them periodically to the Critical Area Commission for review.
- Floodplain Management Overlay (Coastal Velocity Zones) — ADUs added to existing principal dwellings in the floodplain require elevation certificates. The substantial-improvement rule applies if the addition value exceeds 50% of the principal structure's pre-improvement assessed value, in which case the entire structure must be brought into compliance with the elevation standard - a frequent budget-buster on legacy slab-on-grade ocean-bay cottages.
- Forest Conservation Act — Pure interior ADUs rarely trigger FCA; new footprint, land clearing, or grading associated with a detached ADU on a wooded parcel may require Forest Conservation Plan compliance. Worcester is one of the Maryland counties where the Forest Conservation Act is enforced county-wide rather than only on subdivision applications.
- Assateague Island National Seashore Adjacency — Not strictly a zoning overlay - this is an inter-jurisdictional coordination layer that occasionally affects ADU site planning on bay-front parcels, particularly with respect to exterior lighting cutoff and septic-system nitrogen loading near park boundaries.
Known county issues (3)
- policy-review — Worcester County must adopt a Zoning Article ZS Section 1-322 amendment compliant with Maryland HB 1466 / SB 891 (2025 Accessory Dwelling Units Act) by 2026-10-01. The current ordinance caps detached ADUs at 900 sq ft (under 1 acre) or 1,000 sq ft (1+ acre), which falls below the state floor of ADUs up to 75% of the primary dwelling for any primary dwelling exceeding 1,200-1,333 sq ft. The county's owner-occupancy mandate may also be challenged as an 'unreasonable limitation' under HB 1466 unless re-justified on documented public health or safety grounds. Applicants should monitor the County Commissioners' agenda for an amendment and may rely on the self-executing state floor for applications submitted on or after 2025-10-01.
- permitting-friction — Worcester County DRP has not migrated to a full self-service permitting portal (OpenGov, Tyler EnerGov, etc.) of the kind in use in Talbot, Somerset, and most Western Shore counties as of 2026-05. Permit applications still rely on in-person submission at the Government Center in Snow Hill, by mail, or by limited webforms. Expect longer counter time and more paper handling than on the Western Shore; applicants in West Ocean City or the northern end of the county should budget travel time to Snow Hill for in-person counter sessions.
- overlay-burden — Worcester County's Atlantic Coastal Bays Critical Area exposure is the broadest in Maryland - the entire Ocean City barrier island, West Ocean City mainland, Assateague mainland frontage, and the lower-county Chincoteague Bay frontage all fall within the 1,000-foot Critical Area boundary. RCA-classified parcels in the lower county may require a growth-allocation award from the County Commissioners before a detached ADU can be permitted, which adds 6-18 months of process time and is not guaranteed to succeed. IDA/LDA parcels still face buffer-planting and impervious-surface offsets. Worcester applicants should perform a Critical Area classification check at https://gis.co.worcester.md.us/ as the very first step before investing in design work.
Maryland state — ADU law and programs
State ADU law
Maryland enacted statewide ADU preemption with the Accessory Dwelling Units Act of 2025 — HB 1466 / SB 891 (cross-filed) — passed by the General Assembly in the 2025 Regular Session and effective 2025-10-01. Counties and municipalities with planning and zoning authority must adopt local laws compliant with the Act by 2026-10-01. The Act establishes that it is the policy of Maryland to promote and encourage ADU creation on land with a primary single-family detached dwelling. ADUs are defined as secondary units on the same lot/parcel/tract as a primary single-family detached dwelling, no greater than 75% of the size of the primary dwelling. Counties and municipalities cannot prohibit ADUs or impose unreasonable restrictions on their construction or rental. The 2025 ADU Act ALSO amends the Maryland HOA Act (Title 11B of the Real Property Article), prohibiting community associations from prohibiting or unreasonably restricting ADU construction and rental. The state has been preparing this framework since 2023 (SB 382 created the ADU Policy Task Force, which issued its final report 2024-05-31).
State HOA preemption
Maryland enacted HOA preemption for ADUs as part of the 2025 ADU Act. HB 1466 / SB 891 amended the Maryland Homeowners Association Act (Real Property Article, Title 11B), adding the ADU definition at §11B-101(a-1) and prohibiting HOAs from prohibiting or unreasonably restricting the construction or rental of ADUs on lots with primary single-family detached dwelling units. HOAs retain authority to (a) treat an ADU as a separate lot for voting and assessment purposes (optional, not required) and (b) impose reasonable design and architectural standards consistent with the community's overall character. The HOA preemption became effective 2025-10-01.
State financing programs
Maryland does not currently operate an ADU-specific statewide loan, grant, or forgivable-loan program tied to the 2025 ADU Act. The Maryland Department of Housing and Community Development (DHCD) administers a broad portfolio of homeownership, rental development, and home-repair financing — including the Maryland Mortgage Program, Settlement Downpayment Loan Program, Project Restore (commercial-to-residential conversions), and various Energy & Home Repair loan products. None target ADU construction directly, though Project Restore can fund ADU-like conversions, and the Energy & Home Repair Loan can fund ADU-related electrical, HVAC, and weatherization upgrades.
State housing programs
Maryland's primary state-level ADU program is the 2025 ADU Act framework: statewide preemption requiring local jurisdictions to adopt compliant ordinances by 2026-10-01, including HOA preemption. The Maryland Department of Planning maintains an ADU resource hub with technical assistance for local governments. Maryland does not currently operate a statewide pre-approved ADU plan catalog, an ADU rebate, or an impact-fee waiver statute, but the local-compliance window through 2026-10-01 is expected to produce additional ADU-specific incentive programs.
- ADU Act 2025 Statewide Floor (HB 1466 / SB 891) — Counties and municipalities with planning/zoning authority must adopt compliant ordinances by 2026-10-01, allowing ADUs on every single-family-detached lot at up to 75% of primary dwelling size. Bars prohibitions and unreasonable restrictions. Includes HOA preemption.
- Maryland Department of Planning ADU Resource Hub — Resource hub with model ordinances, FAQs for local governments (HB 1466 FAQ), task-force final report, and statewide ADU ordinance inventory.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.