Enacts new GS 160D-917 requiring local governments to allow at least one accessory dwelling that conforms to the North Carolina Residential Code for One- and Two-Family Dwellings for each single-family detached dwelling in areas zoned for residential use that allow for development of single-family detached dwellings. Defines accessory dwelling unit as an attached or detached residential structure that is used in connection with, or that is an accessory to, a primary single-family detached dwelling and that has less total square footage than the primary single-family detached dwelling. Allows the accessory dwelling unit to be built or sited concurrently or after the primary detached dwelling has been constructed or sited. Prohibits a local government from taking six specified actions when permitting accessory dwelling units, including requiring placement in a conditional zoning district, establishing minimum parking requirements or parking restrictions, or setting a maximum unit size of less than 800 square feet. Sets out what a local government can do concerning setbacks, and unit location requirements and size. Specifies that the statute does not apply to: (1) the validity or enforceability of private covenants or other contractual agreements among property owners related to dwelling type restrictions; (2) properties located in a historic preservation district established pursuant to Part 4 of this Article; (3) properties designated as a National Historic Landmark by the US Department of Interior; or (4) an accessory dwelling unit that is not connected to water and sewer. Applies to applications for accessory dwelling unit permits submitted on or after October 1, 2025.

Specifies that a local government that has enacted an ordinance meeting the requirements of this act and GS 160D-917, is not required to adopt a new ordinance.

Requires local governments to adopt development regulations to implement the provisions in this act by January 1, 2027; if they fail to do so, accessory dwelling units will be allowed in that local government without any limitations.