North Carolina’s New ADU Law: Where It Applies and What Changes in 2027

North Carolina has enacted a law requiring certain municipalities to allow accessory dwelling units, or ADUs, alongside detached single-family homes. The new requirements apply to ADU permit applications submitted on or after January 15, 2027.

The important word is “certain.” This is not statewide permission to build a backyard cottage on every residential property. For builders, the first question is whether the law reaches the property. Then you can evaluate what it changes for the proposed project.

Which cities are covered?

The mandate applies to municipalities with at least 50,000 residents that are outside North Carolina’s legally defined coastal area. Counties are not covered by the mandate, and smaller municipalities are not required to allow ADUs under this provision. The statutory term “city” includes incorporated towns and villages.

Charlotte, Raleigh, Greensboro, Durham, and Cary are examples that meet the population and geographic tests. Wilmington and Jacksonville do not qualify because they are in the designated coastal area, even though their populations exceed 50,000. The exclusion follows designated coastal counties, not a property’s distance from the beach.

For communities near the threshold, check the population figures carefully. The state’s July 2025 estimates put Holly Springs at 50,499 residents and Wilson at 50,691. Both exceed 50,000 in that dataset, but the ADU provision does not specify a population source or reference date. Confirm how the municipality will determine applicability before relying on a recent population increase.

Being outside the mandate does not mean ADUs are prohibited. Local ordinances may already allow them. Identify which local government regulates the parcel, then check its rules rather than relying on the city name in the mailing address.

January and July mean different things

January 15, 2027 is when the new statutory requirements begin applying to ADU permit applications. July 1, 2027 is the deadline for covered municipalities to adopt implementing development regulations. An existing ordinance that already complies does not need to be replaced.

The law says ADUs must be allowed “without any limitations” if a covered municipality misses the July deadline. Do not read that as permission to ignore building and fire codes or private covenants, which the statute addresses separately. For a project during this transition, ask the municipality which standards it will apply to the application.

What changes for an ADU project?

Covered municipalities must allow at least one code-compliant ADU for each detached single-family home in residential areas that allow those homes. The ADU can be built with the primary home or afterward. It must be on the same parcel and smaller than the primary home.

The law also limits several requirements that can affect whether a project works:

Size: A municipality cannot set an ADU size cap below 800 or above 1,000 square feet. That is a limit on the local size cap, not a requirement to build an ADU of at least 800 square feet. Nor does it guarantee that a 1,000-square-foot unit is allowed on every property.

Setbacks: The permitted setback minimum is the lesser of 10 feet or the setback generally required for lots in the same zoning classification. For example, that means 10 feet where the general requirement is 20 feet, or 5 feet where the general requirement is 5 feet. A municipality may still require the ADU to sit beside or behind the primary home.

Parking: Municipalities cannot establish minimum parking requirements or other parking restrictions for covered ADUs. The statute expressly includes conversions of existing structures; the protection is not limited to conversions.

Rentals: Municipalities cannot prohibit the primary home and ADU from being rented long-term to separate households. This provision does not establish a right to use the ADU as a short-term rental.

Utilities, fees, and zoning: Municipalities cannot prohibit connection to the primary home’s existing utility systems when those systems have capacity for both homes. They also cannot require placement in a conditional zoning district or charge permitting fees above those for a similar detached single-family dwelling.

What still needs to be checked?

The law preserves the enforceability of private covenants restricting dwelling types. It also excludes properties in locally established historic preservation districts and properties designated as National Historic Landmarks. A property’s eligibility therefore needs more than a population check.

Building and fire requirements still apply. Other local development standards remain relevant unless the law overrides them. Review the proposed layout, height, coverage, and site conditions rather than treating permission for an ADU as confirmation that a particular design will fit. The statute also includes a utility-connection exception, so confirm the water and wastewater arrangement rather than assuming an unconnected unit is covered.

There is also a restriction on separating the homes: after an ADU has been permitted for construction, the parcel cannot be subdivided so that the ADU and primary home end up on different parcels.

Before quoting a project

Start with the jurisdiction and any property-specific exclusions. Then compare the municipality’s ADU standards with the new state requirements and test the proposed layout against the rules that still apply.

For a January 2027 application, the useful question is not simply “Does North Carolina allow ADUs?” It is “Which requirements apply to this ADU, on this property, when we submit the application?” Answering that first gives the homeowner a more reliable starting point for design and pricing.