NC S.L. 2023-108 (HB 409) — Statewide By-Right ADU Mandate (NC)
Tracked preemption from the North Carolina overlay bundle.
Overview
← All state preemptionsNorth Carolina overlay roll-upNorth Carolina zoning wikiNorth Carolina building codesFederal overlaysGlossaryFederal-conflict: Not flagged
Effective
2023-10-01
Sunset
—
Authority
state
Scope
state:NC
Other North Carolina preemptions
NC GS §160D-907 — Family Care Homes as Residential UseNC GS §160D-910 — Manufactured Housing Anti-ExclusionNC GS §160D-914 — Residential Solar Collector ProtectionNC GS §160D-921 — Tree Ordinance Local-Act RequirementNC GS §160D-903 — Bona Fide Farm Exemption from County ZoningNC HB 130 (2021) — Vested Rights Protections for Permit ApplicationsNC GS §160D Article 9 Part 4 — Historic Preservation Commission AuthorityNC GS §160D-702 — Building Design Element Preemption (1-2 Family Detached)
Primary-source summary
**Citation**: Session Law 2023-108 (HB 409), signed into law July 10, 2023, effective **October 1, 2023**. Amends Chapter 160D by adding a new ADU section (codified within the 160D framework).
**Session law text**: [ncleg.gov/Sessions/2023/Bills/House/PDF/H409v6.pdf](https://www.ncleg.gov/Sessions/2023/Bills/House/PDF/H409v6.pdf)
**Bill history**: [ncleg.gov/BillLookUp/2023/H409](https://www.ncleg.gov/BillLookUp/2023/H409)Trigger predicate
When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.
parcel.base_zone_category == res_sfPreempted fields
6 fields on the base district schema are rewritten when the trigger fires.
| Field | Op | Value | Note |
|---|---|---|---|
base_districts[category=res_sf].allowed_uses | add | adu | At least one ADU per lot must be permitted by right wherever single-family detached is permitted by right |
review_type | waive_discretionary | — | No CUP, SUP, or other discretionary approval may be required |
base_districts[category=res_sf].adu_owner_occupancy_required | waive | — | |
base_districts[category=res_sf].adu_additional_parking_required | waive | — | No added parking stall may be required solely because of the ADU |
base_districts[category=res_sf].adu_separate_utility_required | waive | — | |
base_districts[category=res_sf].adu_min_lot_size | cap_at | primary_dwelling_min_lot_size | ADU lot-size minimum cannot exceed the primary dwelling minimum |
Citation
Authority source
Session Law 2023-108 (HB 409), amending Chapter 160D
§ S.L. 2023-108
Research notes
Applies to all 100 counties and all incorporated municipalities. Cities may still regulate setbacks/height/coverage consistent with underlying district, max ADU floor area, building-code/life-safety standards, and STR use per §160D-1207(c). Does not force ADUs into MF or nonresidential districts. Sets a floor; more-permissive local rules preserved.