Backyard cottages, garage apartments and basement suites are about to get a lot easier to build in much of Virginia, though not until next summer.
Beginning July 1, 2027, a new state law will generally require Virginia localities to allow accessory dwelling units, or ADUs, as a permitted accessory use in single-family residential zones. WJLA laid out the changes in an Oct. 15 report on new ADU laws in Virginia and Maryland. The full text is in Section 15.2-2292.4 of the Code of Virginia, passed by the General Assembly in 2026 as Chapter 895 of that year's Acts of Assembly.
What the law says
Under the statute, an ADU is an attached or detached home on the same lot as a primary residence. It has to provide complete independent living facilities, including space for living, sleeping, eating, cooking and sanitation. It can be part of an existing house, a converted garage or a separate building.
Once the law takes effect, anyone who wants to build an ADU must first get an ADU permit from the locality. The permit fee is capped at $500, on top of the usual building, site and inspection fees. The locality must issue the permit if the project meets the law and local codes.
Localities can still require some things, including:
- Rental leases of at least 30 days, which rules out short-term rentals
- Replacement parking if the ADU takes away the main house's required parking, plus dedicated parking for the ADU
- Size limits, as long as they allow at least 350 square feet on lots under 2,500 square feet and at least 500 square feet on bigger lots
- Compliance with building codes, water, sewer, septic, emergency access, flood zone and stormwater rules, plus historic district restrictions
- Owner occupancy of either the ADU or the main house when the application is filed
- An ADU no more than 500 feet from the main house
- No ADU on a lot that already has more than one home, and no selling the ADU separately
Localities can't require larger rear or side setbacks for an ADU than for the main house or other accessory buildings, can't impose stricter height or lot coverage rules than for single-family homes in the same zone, and can't require street improvements, except to repair damage from construction. They also can't require the people living in the ADU to be related to the people in the main house, and can't make the owner record a restrictive covenant about the ADU.
The fine print
The law doesn't apply everywhere. It does not cover localities that adopted their own ADU ordinance before Jan. 1, 2026. Localities can also pass their own ordinance before July 1, 2027, as long as it substantially complies with the state law. ADU permits a locality approved before July 1, 2027, are also left alone.
The law also does not override private agreements. HOA declarations, condominium documents and recorded covenants still apply, so a homeowner in a community with rules against ADUs may still be out of luck.
Supporters say ADUs can provide rental housing, bring in income for homeowners or give an aging parent or adult child a place of their own, according to WJLA. The station also noted that construction costs are a big hurdle. A new detached unit may cost hundreds of thousands of dollars, depending on size, design, site prep and utility connections.
Why it matters for Contractors
For remodelers and small builders, this could open a new line of work across Virginia. Garage conversions, basement apartments, attic suites and small detached homes are all on the table, and the $500 cap on the ADU permit fee keeps one of the up-front costs predictable.
But the law doesn't make the job simple. ADUs still need full building code compliance, and in rural areas septic capacity can make or break a project. Utility connections, stormwater, flood zones and historic districts can add cost and time. Contractors who can walk a homeowner through feasibility, pricing and permits from the start will have an edge.
The timeline matters, too. The law takes effect July 1, 2027, but some localities already have their own rules, and others may adopt new ordinances before then. Before quoting a job, check with the local planning office to see which rules apply and whether the property sits under an HOA or covenant that could block it.