Building an ADU in North Carolina

What the 2026 ADU law requires

Session Law 2026-59 is the Regulatory Reform Act of 2026. Section 44 adds a new section to the state's land-use law, G.S. 160D-917. Governor Josh Stein signed the act on August 11, 2026.

A covered city "shall allow the development of at least one accessory dwelling unit" for each single-family detached home in areas zoned for residential use that allow single-family detached homes. The ADU must meet the North Carolina Residential Code, including fire code provisions. You can build it at the same time as the main house or later.

The law defines an ADU as an attached or detached home that goes with a single-family detached house on the same parcel and has less total square footage than the house.

When it permits ADUs, a covered city may not:

• ban long-term rentals of the house and the ADU by separate households;
• require the property to be placed in a conditional zoning district;
• set minimum parking or other parking restrictions, including extra parking when you convert an existing structure into an ADU;
• ban connecting the ADU to the utilities that serve the house, if that service has capacity for both;
• charge more in fees than it charges to permit a similar single-family detached home;
• set a maximum ADU size of less than 800 square feet or more than 1,000 square feet.

Once an ADU has been permitted for construction, the parcel can't be subdivided so that the ADU ends up on a different parcel from the house. [1][2]

Who is covered, and when

G.S. 160D-917 applies only to cities with 50,000 or more people that are not in the coastal area. State law defines the coastal area as the counties on the Atlantic Ocean or a coastal sound. The 20 counties listed as of July 1, 2012 are Beaufort, Bertie, Brunswick, Camden, Carteret, Chowan, Craven, Currituck, Dare, Gates, Hertford, Hyde, New Hanover, Onslow, Pamlico, Pasquotank, Pender, Perquimans, Tyrrell and Washington.

The section does not apply to counties or to towns under 50,000. In those places, your local zoning code still decides whether you can build an ADU.

The state demographer's estimates for July 1, 2025 put Charlotte at 959,079 people, Raleigh at 504,445 and Asheville at 97,700, so all three are well over the threshold. See our guides for Charlotte, Raleigh and Asheville.

The requirement applies to ADU permit applications filed on or after January 15, 2027. Covered cities must adopt development regulations to carry it out by July 1, 2027. A city whose ordinance already meets the law doesn't have to adopt a new one. If a city misses the July 1, 2027 deadline, the law says ADUs "shall be allowed in that local government without any limitations." [1][3][4]

What cities can still require

The law lets a covered city:

• require a setback for ADUs of 10 feet, or the setback that generally applies to lots in the same zone, whichever is less;
• require the ADU to sit to the side or rear of the house;
• require the ADU to be smaller than the house.

Apart from the limits above, cities can still regulate ADUs under Chapter 160D. The law also says it doesn't limit ordinances a city adopts to comply with state and federal laws, rules, regulations or permits.

The law does not apply to properties in a local historic preservation district or to National Historic Landmarks, or to an ADU that is not connected to water, well and septic, and sewer. It also does not override private covenants or other agreements among owners about dwelling types, so it does not change what your deed restrictions or HOA covenants allow.

State law already says zoning can't set a minimum square footage for homes built under the North Carolina Residential Code, or require a parking space larger than 9 by 20 feet in most cases. [1][5]

Earlier ADU bills that did not pass

In 2025, House Bill 627 and its twin, Senate Bill 495, both titled "Regulation of Accessory Dwelling Units," would have required all local governments to allow ADUs starting October 1, 2025. They had no 50,000-population limit, and they barred size caps under 800 square feet without the 1,000-square-foot upper limit in the final law. House Bill 627 was re-referred to the House Rules committee on May 7, 2025, and Senate Bill 495 was referred to the Senate Rules committee on March 26, 2025. Neither passed.

Senate Bill 497, "Expand Middle Housing," and House Bill 765, the "Save the American Dream Act," also stalled in committee in 2025. The ADU rule that became law is the narrower version in Senate Bill 445. [1][6][7][8][9][10]

Building permits: review times and fees

If your city or county reviews residential building plans, state law says "all initial reviews for the building permit shall be performed within 15 business days of submission of the plans." If the first review takes more than 20 business days, the local government must refund 10% of the total permit application fee for each extra business day, for up to 10 business days.

A local government can't require plans for one- and two-family homes to be sealed by an engineer or architect unless the State Building Code requires it.

Since August 11, 2026, every local government must post its current fee schedules on its website. It must give you a fee estimate within 10 business days after you submit a complete application and can't make you pay those fees before it gives you the estimate. When it approves your project, it must give you a final fee statement that can't exceed the latest estimate unless it has adopted a new fee schedule. You can sue in superior court to make it comply.

For the overall process, see our ADU permit process guide and ADU cost guide. [1][11]

Building it yourself

North Carolina requires a licensed general contractor for building work that costs $40,000 or more. There is an exemption for an owner who builds on their own land if the building is "intended solely for occupancy by that person and his family." If the owner and family don't live in the building for at least 12 months after it's finished, the law presumes the exemption didn't apply.

To use the exemption, you sign a sworn affidavit when you apply for the permit. In it you state that you own the property, will personally manage all of the construction and will be present for the required inspections, unless a licensed architect drew and sealed the plans.

If you plan to rent the ADU, ask your building department how the exemption applies. Our Raleigh guide shows how one city handles it. See our guide to hiring ADU help. [12][13]

What to check with your city or county

Until January 15, 2027, and in places the new law doesn't cover, ADU rules are local. Ask your planning or zoning office:

• whether your zoning district allows an ADU, and whether it can be attached, detached or inside the house;
• the maximum ADU size, height and setbacks;
• parking and driveway rules;
• whether the city's ordinance is being updated for G.S. 160D-917;
• the permit, plan review and water and sewer fees.

Our garage conversion guide and backyard tiny house guide cover the general options. [1][5]

North Carolina laws to know

• G.S. 160D-917, enacted by Session Law 2026-59 (Senate Bill 445), Section 44

  Requires cities of 50,000 or more outside the coastal area to allow at least one ADU per single-family detached home and limits parking, fee, size and setback rules, starting January 15, 2027. [1][2]

• G.S. 160D-402.1, development fee transparency (Session Law 2026-59, Section 49)

  Requires local governments to post fee schedules online, give a fee estimate within 10 business days of a complete application and issue a final fee statement that can't exceed the latest estimate unless it adopts a new fee schedule by ordinance. [1]

• G.S. 160D-702, zoning powers

  Gives local governments zoning power and bars them from setting a minimum square footage for homes built under the North Carolina Residential Code. [5]

• G.S. 160D-1110, building permits

  Sets a 15-business-day deadline for a local government's first review of residential building plans and requires a partial permit fee refund when the review takes more than 20 business days. [11]

• G.S. 87-1 and 87-14, general contractor licensing

  Require a licensed general contractor for work costing $40,000 or more, with an exemption for owners building for their own family's occupancy. [12][13]

• House Bill 627 and Senate Bill 495 (2025), earlier ADU bills (did not pass)

  Would have required every local government to allow ADUs from October 1, 2025; both stalled in Rules committees in 2025. [6][7][8]

Questions people ask