Virginia Buyers Guide

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Virginia Accessory Dwelling Unit (ADU) Buying Guide

Updated as of August 2025

This free guide is designed to help homeowners, buyers, and investors navigate the process of purchasing, building, or adding an Accessory Dwelling Unit (ADU) in Virginia. ADUs—also known as granny flats, in-law suites, or backyard cottages—are secondary living spaces on a single-family property. They can be attached (e.g., basement apartment) or detached (e.g., standalone cottage). This guide focuses on state-level rules and key local variations, but always consult your local zoning office for site-specific details. Note: Maryland guide coming soon.

1. What is an ADU?

An ADU is a self-contained residential unit located on the same lot as a primary single-family home. It includes its own kitchen, bathroom, and sleeping area. In Virginia, ADUs are increasingly popular for providing affordable housing options, generating rental income, or accommodating family members. They differ from short-term rentals (e.g., Airbnb) and must comply with long-term occupancy rules in most areas.

Key Types of ADUs in Virginia:

• Attached ADU: Built within or added to the main house (e.g., converted garage or basement).
• Detached ADU: Standalone structure in the yard.

2. Benefits of Buying or Building an ADU in Virginia

• Income Potential: Rent out the ADU for supplemental income (average $1,500–$2,500/month in suburban areas like Fauquier County).
• Family Support: House aging parents, adult children, or caregivers without separate properties.
• Property Value Boost: ADUs can increase home value by 20–30% in high-demand areas.
• Affordable Housing Solution: Addresses Virginia's housing shortage; state incentives may apply.
• Tax Advantages: Potential deductions for home office use or rental depreciation (consult a tax advisor).
• Sustainability: Smaller units promote efficient land use and can include eco-friendly features like solar panels.

3. Virginia State Regulations for ADUs (As of 2025)

Virginia has made significant strides in promoting ADUs through recent legislation. In 2025, Senate Bill 304 (SB304) and related bills like SB932 and HB900 mandate that localities allow ADUs "by right" in single-family zoning districts, reducing barriers. This means no special use permits are needed if basic standards are met, though local variations exist.

Key State Requirements:

• Permit Process: Obtain an ADU permit from your locality (fee capped at $250–$500 per SB304/SB932).
• Size Limits: Typically up to 1,500 sq ft or 50% of the primary home's size (whichever is smaller). Detached ADUs may have stricter caps (e.g., 800 sq ft in some areas).
• Setbacks and Design: ADUs must match the primary home's style; setbacks are restricted (e.g., no closer than 5–10 ft to property lines).
• Occupancy: Limited to long-term rentals (no short-term like Airbnb unless locally allowed). No affinity requirements (e.g., must be family) in most cases post-2025 updates.
• Utilities and Parking: Share utilities with the main home; off-street parking may be required (1–2 spaces), though some localities waived this in 2025 (e.g., Norfolk).
• Building Codes: Must comply with Virginia Uniform Statewide Building Code (VUSBC), including energy efficiency and accessibility standards.

Recent Changes (2024–2025): A state workgroup refined ADU policies after SB304 passed the Senate but stalled; updates include easier approvals and fee caps. Localities like Falls Church and Norfolk updated ordinances in 2025 to align.

4. Local Variations in Virginia

Regulations vary by city/county—check your local zoning ordinance via the municipal website or office.

• Fauquier County (e.g., Warrenton, The Plains): Allowed in rural/residential zones (R-1, RA, etc.); max 800–1,000 sq ft; septic/well approval needed if no public utilities. No minimum lot size, but larger for bigger ADUs.
• Virginia Beach: Size up to 50% of primary; lot must be 5,000+ sq ft; by-right in many zones post-2025 updates.
• Chesapeake: Similar size limits (50% cap); focus on stormwater and setbacks.
• Fairfax County: Workforce Dwelling Units (WDUs) integrated with ADUs; administrative guidelines updated in 2025.
• Hampton: Ordinance amendments expected by end-2025; community input ongoing.
• Norfolk: Increased size to 800 sq ft max; removed parking requirements in April 2025.

For your area, use tools like Virginia's Locality Zoning Search or contact the Department of Housing and Community Development.

5. Costs of Buying or Building an ADU in Virginia

• Prefabricated ADUs: $95,000–$175,000 (e.g., modular units from companies like Maryland MicroNest). Quick install (weeks).
• Custom-Built: $100,000–$300,000+ (includes permits, site prep, utilities).
• Conversion (e.g., Garage): $20,000–$100,000.
• Additional Fees: Permits ($250–$500), inspections ($500–$1,000), utilities hookup ($5,000–$20,000 if septic/well needed).
• ROI Timeline: 3–5 years via rentals, depending on location.

6. The Buying/Building Process

• Research Zoning: Confirm ADU allowance via local planning department.
• Design and Plans: Hire an architect or use pre-approved designs (some localities offer templates).
• Permits: Submit application with site plans; approval in 30–60 days.
• Financing: Options include home equity loans, HELOCs, or Virginia Housing grants for low-income projects.
• Construction: Hire licensed contractors; timeline 2–6 months.
• Inspections and Occupancy: Final checks for code compliance.
• Rental Setup: If renting, get landlord insurance and comply with Virginia Residential Landlord and Tenant Act.

Tips for Buyers: When purchasing a property with an existing ADU, verify permits and inspections. For new builds, consider pre-fab for speed.

7. Financing and Incentives

• Loans: FHA 203(k) for renovations including ADUs; conventional loans up to 100% LTV.
• Grants/Tax Credits: Virginia Housing's SPARC program for affordable units; federal energy credits for green ADUs.
• Local Incentives: Some counties offer fee waivers or density bonuses.

8. Common Challenges and Solutions

• HOA Restrictions: If in an HOA, check covenants (state law may override post-2025).
• Septic/Well Issues: Rural areas require Health Department approval.
• Neighbor Concerns: Address privacy with landscaping.
• Short-Term Rentals: Restricted in many areas; focus on long-term.

9. FAQs

• Do I need to live on the property? Yes, owner-occupancy is required in most localities.
• Can ADUs be sold separately? No, they stay with the primary lot.
• Are ADUs taxable? Yes, as part of property assessment—increases value but may qualify for exemptions.
• Where to start? Contact your local zoning office or Maryland MicroNest.