ADU Pass
Adamstown
ADU Pass helps homeowners in Adamstown, Frederick County, Maryland navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
Frederick County — county ADU rules and overlays
County ADU ordinance
Frederick County sits in Maryland, which has enacted statewide ADU preemption. Local jurisdictions retain limited authority over objective design standards, but may not deny a code-compliant ADU on a single-family-zoned lot. The county's ordinance for unincorporated territory must conform to the state floor; where it conflicts, the state law controls.
State-floor overlay: Maryland preemption establishes a state floor for ADU permissibility; the county ordinance must respect it.
County regulatory overlays
Frederick County administers flood-hazard, and (where mapped) coastal, wildland-fire, historic, and airport overlays that shape ADU project feasibility. The most consistent overlay across the county is FEMA NFIP floodplain regulation; other overlays apply to specific geographies inside the county.
- FEMA NFIP Special Flood Hazard Areas in Frederick County — A new ADU in a mapped SFHA must be elevated to or above the Base Flood Elevation; cost impact on the project is often material.
- Historic districts and individually-listed historic resources
County permitting (unincorporated parcels)
Frederick County issues building permits for parcels in unincorporated territory through its development services / planning department, with separate review tracks for zoning conformance, building-code compliance, on-site sewage where applicable, floodplain compliance, and addressing. Inside incorporated municipalities, city departments handle their own permits; the county's authority is geographically limited to unincorporated territory. An ADU permit application is typically processed as a residential building permit with a zoning verification step against the county's ordinance for the parcel's zoning district.
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.
ZIP Code
- 21710
Post Office
- 5537 Mountville Rd, 21710