West Virginia ADU law: what SB 659 lets you build

What state law lets you build

Senate Bill 659 passed on March 6, 2026, and the governor approved it on March 14, 2026 (Chapter 241, Acts of 2026). It took effect June 4, 2026, 90 days from passage.

The bill created a new article on ADUs, numbered 8-40 in the bill. The official code now lists it as W. Va. Code 8-42-1 to 8-42-3.

The key sentence says a municipality "shall not adopt a policy, regulation, or ordinance that restricts, prohibits, or otherwise regulates the use of at least one accessory dwelling unit by right on a lot or parcel that contains a single-family dwelling." The ADU can be attached, detached, or internal to the house.

The law defines an ADU as a self-contained, independently accessed living unit with its own cooking, sleeping and sanitation facilities, on the same parcel as a larger single-family home.

"By right" means approval without a public hearing, a variance, a conditional use permit, a special permit or exception, or other discretionary zoning action. The only zoning check allowed is whether your site plan and any construction plans meet the applicable requirements. [1][3][4][5]

Who is covered: cities and towns, not counties

The law applies to municipalities. In West Virginia's municipal code, "municipality" means any Class I, II or III city and any Class IV town or village. The ADU article does not mention counties.

If your home is inside the limits of a city, town or village, the law applies to its rules. If you live outside municipal limits, the law does not say what applies, so ask your county planning office. [1][6]

What cities can and can't require

Size. If the ADU is attached or detached, "it shall not be more than 75 percent of the gross floor area of the single-family dwelling or 1,000 square feet, whichever is less." Gross floor area means the interior habitable area. For example, with a 1,200 sq ft house, 75% is 900 sq ft, so 900 sq ft is the cap.

Height, setbacks and lot size. A city may not set height limits, setbacks, minimum lot sizes, lot coverage limits or frontage rules for the ADU that are stricter than those for the house on the lot. It also may not impose "more onerous development standards" on an ADU beyond those in the law.

Parking. A city may not require extra parking for an ADU, or a fee in place of parking.

Design. A city may not require the ADU to match the house's exterior design, roof pitch or finishing materials. The exception is a historic district, where a city may require matching design under an ordinance adopted to preserve that district.

Who lives there. A city may not require a family, marriage or employment link between the people in the house and the people in the ADU. The law's list does not mention owner occupancy, so ask your city whether it requires the owner to live on the property.

Street work. A city may not require street or sidewalk improvements as a condition of the permit, except to repair a street or sidewalk your construction disturbs.

Utilities. A city may not require water and sewer for the ADU separate from the main house. It may require a will-serve letter from both the water system and the sewer system that serve the main house, or Department of Health approval where municipal or private water or sewer service isn't available.

What still applies. The law does not override "applicable regulatory requirements," which include the West Virginia Fire Code, local ordinances, zoning, design and construction standards including building codes, and other federal, state and local laws. A city may also adopt rules that are more generous. [1][2][5]

Fees

A city may charge a fee to review your ADU application, but it "may not exceed $250 for each accessory dwelling unit." The city may still charge its usual building fees on top of that.

A city may not "assess development impact fees in excess of $250 on the construction of an accessory dwelling unit."

For what the rest of a project costs, see our ADU cost guide and ADU financing guide. [1][2]

Manufactured homes as ADUs

The law has its own rules for manufactured homes. "A manufactured home may be used as an accessory dwelling unit by right on a lot or parcel that contains a single family dwelling in any zoning district where accessory dwelling units are permitted."

A city may not prohibit or unreasonably restrict a manufactured-home ADU, as long as it is on a permanent foundation and meets building, fire and safety codes. A city may not impose design, aesthetic, age-of-construction or prior-use rules on it that are stricter than for a site-built ADU of similar size.

A manufactured home used as an ADU is assessed and taxed as real property. It may share water, sewer and utility connections with the main house. Separate connections or meters may be required only where needed to protect public health and safety, and only if the rule applies to all ADUs.

The law defines a manufactured home as one built to the federal manufactured home construction and safety standards and installed on a permanent foundation. For more on small homes in a backyard, see our backyard tiny house guide. [1][5]

HOA covenants and short-term rentals

Covenants. A city may not require a restrictive covenant about an ADU on a lot zoned for a single-family home, and it may not make your permit depend on one. The law does not stop private parties from agreeing to covenants about ADUs. If your lot has covenants, read them before you plan an ADU.

Short-term rentals. The law "does not prohibit a municipality from regulating short-term rentals," which it defines as rentals for 30 days or less. Check your city's rules before you list the ADU on a rental site. [1][2][5]

If your city says no

The law has been in effect since June 4, 2026. Its deadline for local rules is January 1, 2027: "A policy, regulation, or ordinance in effect on or after January 1, 2027, that applies to an accessory dwelling unit and does not comply with this article is invalid to the extent of its conflict with this article." Until then, your city's current rules may not yet match the state law, so ask your planning office how it is applying it.

If your city points to a rule that seems stricter than the law, ask the planning office in writing which rule it is applying and how that rule fits with W. Va. Code 8-42-2. Fire, building, zoning and other "regulatory requirements" still apply, so some limits may come from those rules. The law does not name a state agency that takes complaints.

For a general walk-through of plans, permits and inspections, see our ADU permit process guide. Montana has a law with very similar wording; see our Montana page. [1][2][3][5]

West Virginia laws to know

• SB 659 (2026), W. Va. Code 8-42-1 to 8-42-3

  Bars municipalities from restricting at least one ADU by right on a single-family lot, sets the ADU's maximum size, bars extra parking, caps fees and limits rules on manufactured-home ADUs. [1][3][4]

Questions people ask