ADU Pass
Grimstead
ADU Pass helps homeowners in Grimstead, No County, Virginia navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
ADU details
ADU legality: unclear
Mathews County's lack of explicit ADU ordinance creates ambiguity — accessory structures are permitted but their use as habitable dwellings is case-by-case via CUP. Most Grimstead parcels are on private well and septic; soil suitability and waterfront overlay (Chesapeake Bay Preservation Act RPA) are the governing constraints. Post-July 2027, SB531's statewide mandate may compel Mathews to adopt clearer ADU rules.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 200 | $550 | $56,000 | $56,550 |
| 600 | 600 | $850 | $168,000 | $168,850 |
| midpoint | 600 | $850 | $168,000 | $168,850 |
| maximum | 1,000 | $1,050 | $280,000 | $281,050 |
Fee breakdown (as of 2026-05)
Permitting process
Viability (permitted uses)
- Long-term rental: with-restrictions Long-term rental of habitable accessory structure allowed only after CUP approval given Mathews's lack of by-right ADU framework.
- Short-term rental: with-restrictions Mathews permits STRs subject to county registration and transient occupancy tax. Waterfront Grimstead parcels see significant STR demand for Chesapeake Bay tourism (Gwynn's Island, kayaking, boating).
- Office rental: no Office rental to third parties not permitted without rezoning.
- Home office: yes Home occupation permitted under Mathews zoning with restrictions.
- Studio / workshop: yes Personal artist or studio is a permitted accessory use.
- Agriculture: yes Mathews has substantial agricultural and rural-residential zoning; farm-worker housing typically by-right in A-1.
- Relative support: with-restrictions Multigenerational family-member occupancy in accessory structure may require CUP if not within primary dwelling.
Contacts
Utilities
- Water: Private well (most Grimstead parcels) · 30d connect · $8,000
- Sewer: Private septic (most Grimstead parcels); waterfront parcels have additional CBPA constraints on drainfield siting · 60d connect · $18,000
- Electric: Dominion Energy Virginia or Northern Neck Electric Cooperative depending on parcel · 35d connect · $2,400
- Gas: Propane delivered (no natural gas mains) · 14d connect · $1,900
Property values & taxes
Construction timeline
Realistic total: best 8mo · typical 12mo · worst 18mo
Modular pathway inspectors are occasional with modular
Routes 14, 198, and 33 are narrow rural routes; bridge access from Gloucester is the only land route to Mathews peninsula. Wide-load transport requires careful route survey.
Financing
State ADU loans:
Insurance impact
HOA prevalence & preemption
Rural Mathews has minimal subdivision activity; HOA presence very low. Most parcels are independent rural or waterfront homesteads.
Regulatory overlays (2)
- wetland-overlay
Virginia Chesapeake Bay Preservation Act (CBPA) Resource Protection Area (100-ft tidal buffer) and Resource Management Area (50-ft additional) apply to most Grimstead parcels. Mathews County is a tidewater locality; CBPA review and Wetlands Board approval add 30-90 days plus engineering costs for septic/drainfield siting on waterfront parcels. - flood-zone
Significant portions of the Mathews peninsula (including Grimstead) are in FEMA Zone AE or VE (velocity flood/coastal high-hazard zones); new construction requires flood-resistant design per ICC 500 / VUSBC.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Mathews County Zoning Ordinance (no explicit ADU provisions), adopted 1995-01-01, last amended 2023-01-01
- 1989-01-01 — Virginia Chesapeake Bay Preservation Act (CBPA) Resource Protection Area (RPA) regulations (state-law)
Virginia CBPA imposes 100-foot Resource Protection Area buffer on tidal shorelines and 50-foot Resource Management Area buffer applicable to most Grimstead waterfront and near-water parcels.
Effect: Establishes major dimensional constraint for new construction (including ADUs) on Grimstead waterfront parcels. - 2026-04-14 — Virginia SB531 signed into law (state-bill)
Statewide ADU mandate effective July 1, 2027 with permit fee cap and prohibition on excessive setback rules.
Effect: May compel Mathews County to adopt explicit ADU rules; Mathews's lack of pre-2026 ADU ordinance suggests SB531's by-right mandate will apply post-July 2027.
Known issues (3)
- policy-review — Adds case-by-case CUP review uncertainty; outcomes vary by Planning Commission/BOCS composition.
- other — Reduces available ADU footprint by 30-80 percent on waterfront parcels; engineered drainfields and special site plans needed.
- other — Substantially increases construction cost on flood-zone parcels.
County: no attribution (synthetic bucket)
No county
This city sits in the state's "no county" bucket — its ADU rules derive directly from state law and city ordinance without a county intermediary. No county-level sections apply.
Virginia state — ADU law and programs
State ADU law
Virginia has NOT enacted a statewide ADU preemption law. Virginia is a Dillon Rule state — localities possess only those powers expressly granted by the General Assembly — and the statutes granting zoning authority (Va. Code § 15.2-2280 et seq.) leave ADU regulation to local ordinances. ADU permission, setbacks, parking, size, and owner-occupancy rules therefore vary by county, independent city, and town. Virginia is unique in that it has 38 independent cities that function as counties (neither in nor subordinate to the surrounding county), meaning 'the county' for any given Virginia property may be an independent city rather than a true county. Several ADU preemption bills have been introduced in recent General Assembly sessions (2022 through 2025) without enactment; none have advanced past committee as of the Assembly's 2026 regular session adjournment.
State financing programs
Virginia does not operate an ADU-specific statewide loan, grant, or forgivable-loan program. Virginia Housing (formerly the Virginia Housing Development Authority, VHDA — rebranded 2020) administers general first-time-homebuyer, down-payment-assistance (DPA), mortgage-credit-certificate, and rehabilitation products that can be applied to ADU-adjacent purchases or improvements when eligibility criteria are met, but none target ADU construction as a distinct product. The Virginia Department of Housing and Community Development (DHCD) administers federal HOME and CDBG pass-through funds that local jurisdictions can direct toward ADU-adjacent rehab, but there is no state-level ADU-dedicated line item. Federally available products (FHA 203(k), Fannie Mae HomeReady and HomeStyle Renovation, Freddie Mac CHOICERenovation) remain the primary ADU financing path for Virginia homeowners.
State housing programs
Virginia does not run a state-level pre-approved-ADU-plan catalog, statewide impact-fee-waiver statute for ADUs, or streamlined-review mandate. State-level programs that touch ADU-adjacent policy are coordinated primarily through the Department of Housing and Community Development (DHCD) and Virginia Housing, and act by funding or assisting local jurisdictions rather than by preemption. Local ADU activity — Arlington County's Accessory Dwellings program (detached ADUs permitted since 2008, liberalized 2020), Alexandria's accessory-dwelling ordinance, Fairfax County's accessory-living-unit program, and Charlottesville's 2021 zoning-code changes — is authorized under the localities' Va. Code § 15.2-2280 zoning authority, not by state mandate.
- DHCD Community Development Block Grant (CDBG) Program — Federal CDBG funds administered by DHCD to eligible non-entitlement Virginia localities for community-revitalization, housing-rehab, and infrastructure projects. Not ADU-specific. Participating localities can direct CDBG funds toward housing-rehab projects where local policy supports ADUs.
- DHCD HOME Investment Partnerships Program — Federal HOME funds administered by DHCD to Virginia participating jurisdictions and non-profits for affordable-housing acquisition, rehab, and new construction. Not ADU-specific; can be directed to ADU-adjacent rehab at local discretion.
- Virginia Housing Commission — Permanent advisory commission of the General Assembly that studies housing-policy questions and recommends legislation. Has periodically studied ADU preemption and missing-middle housing without recommending statewide enactment as of 2026-04-21.
- Local ADU ordinances under Va. Code § 15.2-2280 authority — Not a state program — listed here because Virginia ADU policy is executed entirely at the locality level under the § 15.2-2280 zoning grant. A homeowner seeking to build an ADU consults the zoning ordinance of the specific county, city, or town where the parcel is located.
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
- 23064
Post Office
- 1150 Old Ferry Rd, 23064