Arkansas ADU law: what Act 313 lets you build

What state law lets you build

Act 313 of 2025 (House Bill 1503) added section 14-56-205 to the Arkansas Code. The governor approved it on March 18, 2025.

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 (1) accessory dwelling unit by right on a lot or parcel that contains a single-family dwelling."

Your ADU can be attached to the house, detached, or internal (inside the existing house).

The act 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 meets the applicable requirements. [1][2]

Who is covered: cities, not counties

The act is written for municipalities. Its title calls it an act "to amend the law concerning municipal regulations," and each of its rules is addressed to "a municipality." It does not mention counties.

If your home is inside city limits, the act applies to your city's rules. If you live outside city limits, the act does not say what applies, so ask your county planning office. [1]

What cities can and can't require

Size. If the ADU is attached or detached, it "shall not be more than seventy-five percent (75%) of the gross floor area of the single-family dwelling or one thousand square feet (1,000 sq. ft.), 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 act.

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.

Who lives there. A city may not require that the owner live in the house or the ADU. It also can't require a family, marriage or employment link between the people in the house and the people in the ADU.

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

What still applies. The act does not override "applicable regulatory requirements," which it defines to include the Arkansas Fire Prevention Code, local ordinances, applicable zoning, design standards and other state and local laws. A city may also adopt rules that are more generous than the act. [1]

Fees

A city may charge a fee to review your ADU application, but it "shall not exceed two hundred fifty dollars ($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 on building an ADU "in excess of two hundred fifty dollars ($250)."

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

When the law took effect

Act 313 has no emergency clause and no effective date of its own. The Arkansas Attorney General's Opinion No. 2025-032 says acts of the 2025 regular session without an emergency clause or a specified effective date "become effective on Tuesday, August 5, 2025."

The act also sets a second date: "A policy, regulation, or ordinance in effect on or after January 1, 2026, that applies to an accessory dwelling unit and does not comply with this section is invalid to the extent of its conflict with this section." [1][3]

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 act 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 act "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]

If your city says no

Since January 1, 2026, a city ADU rule that doesn't comply with section 14-56-205 is "invalid to the extent of its conflict with this section." The act does not name a state agency that takes complaints.

If your city points to a rule that seems stricter than the act, ask the planning office in writing which rule it is applying and how that rule fits with A.C.A. 14-56-205. Keep in mind that fire, building, zoning and other "regulatory requirements" still apply, so some limits may come from those rules.

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]

Arkansas laws to know

• Act 313 of 2025 (HB 1503), A.C.A. 14-56-205

  Bars municipalities from restricting at least one ADU by right on a single-family lot, sets the ADU's maximum size, bars parking and owner-occupancy requirements, and caps fees. [1][2]

Questions people ask