Accessory Dwelling Unit (ADU) Permit in Las Cruces, New Mexico

Las Cruces requires an accessory dwelling unit (adu) permit for: Zoning authorities in New Mexico, including home-rule municipalities such as Las Cruces, must accommodate construction of one additional dwelling unit per lot within a single-family zoning district, regardless of lot size, per NMSA 1978 § 3-21-1 (as amended by 2023 House Bill 425); Statewide floor: the additional dwelling unit may not exceed 1,000 square feet; Statewide floor: side and rear setbacks no more than 5 feet from the property line and 10 feet from any other structure on the property; A zoning authority may not impose a single-family or owner-occupancy requirement specific to the additional dwelling unit as a condition of the permit; Lack of adequate water, sewer, or other infrastructure capacity alone may not be used as a basis to delay or deny a building permit for the additional dwelling unit, per the statute; The ADU structure itself is permitted as residential new construction — apply through the standard Residential Building Permit process (site plan, construction plans, ownership documentation) via the City of Las Cruces Citizen Portal (Accela); Trade permits (electrical, plumbing, mechanical) apply separately if the ADU includes those systems. If your project isn't listed, confirm with City of Las Cruces Community Development Department — Building and Development Services (One Stop Shop) at 575-528-3222 before starting work.

Las Cruces does not publish a separate ADU fee category. An ADU is billed under the same Residential Building Permit Fee schedule as new construction: $0.20 per square foot of gross floor area, with a $50 minimum, plus a 25% plan check fee. Source: City of Las Cruces 2023 Schedule of Fees.

3 days. Las Cruces does not run a separate review track for ADUs — an ADU permit is processed as a standard Residential Building Permit, and the City's Residential Construction Process guide sets a 3-day plan review timeline for all project types (with no exception for flood-zone projects). Source: City of Las Cruces Residential Construction Process guide.

You'll need: Building Permit Application; Site Plan; Construction Plans with Work Description. See the required-documents checklist on this page for details on each.

Las Cruces requires 3 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation, Frame, Final. Schedule each through City of Las Cruces Community Development Department — Building and Development Services (One Stop Shop) (575-528-3222).

Apply through City of Las Cruces Community Development Department — Building and Development Services (One Stop Shop) at 700 N. Main St., Suite 1100, P.O. Box 20000, Las Cruces, NM 88001. Phone: 575-528-3222, email: inspectionrequest@lascruces.gov. Office hours: Monday, Tuesday, Thursday, Friday 7:30 AM - 5:00 PM; Wednesday 8:00 AM - 2:00 PM (afternoon closed for admin/training); online access 24 hours. Official information: https://lascruces.gov/property/remodeling-and-construction/.

Las Cruces, New Mexico has adopted: New Mexico is a statewide-minimum-code state under the Construction Industries Licensing Act (NMSA 1978 § 60-13-44(E)): 'All political subdivisions of the state are subject to the provisions of codes adopted and approved under the Construction Industries Licensing Act. Such codes constitute a minimum requirement for the codes of political subdivisions.' A county or municipality may become its own code-enforcement authority (operate independently of the state Construction Industries Division field offices) if it employs a certified building official and has adopted at least the current state minimum code standards (NMSA 1978 § 60-13-41(D)-(F)). The City of Las Cruces operates its own Building and Development Services / Community Development Department with its own building official and inspection staff (rather than routing permits through the state CID field office model used in unincorporated areas), enforcing the state-adopted codes as the applicable minimum within city limits.; 2021 New Mexico Commercial & Residential Building Code (based on the 2021 IBC / 2021 IRC), per NM Construction Industries Division (CID) current adoption; 2021 International Building Code (IBC), as adopted/amended by CID; 2021 International Residential Code (IRC), as adopted/amended by CID; 2021 New Mexico Energy Conservation Code (based on the International Energy Conservation Code, IECC) — addresses the New Mexico climate zone for energy conservation; applies to new and renovated residential and commercial buildings; 2021 New Mexico Plumbing and Mechanical Code, incorporating the 2021 Uniform Mechanical Code (IAPMO) and 2021 Uniform Plumbing Code (IAPMO); 2020 New Mexico Electrical Code / 2020 National Electrical Code (NEC), adopted by reference at 14.10.4 NMAC, effective March 28, 2023 (permits issued only under this rule after September 28, 2023) — this is the current, in-force edition; it supersedes any references to a 2023 NEC edition found on third-party aggregator sites; 2012 Solar Energy Code (IAPMO), as adopted by CID; 2017 ICC/ANSI A117.1 (Accessible and Usable Buildings and Facilities), as adopted by CID; 2012 Uniform Swimming Pool, Spa and Hot Tub Code, as adopted by CID; Las Cruces Land Development Code, Chapter 30 (Buildings and Building Regulations) and Chapter 38 (Zoning) — local building-permit administration, fee schedule, and zoning provisions. Local amendments apply — see the Las Cruces overview page for the full list.

Yes. New Mexico state law (NMSA 1978 § 3-21-1, as amended by 2023 House Bill 425) requires zoning authorities, including home-rule municipalities like Las Cruces, to accommodate one additional dwelling unit per lot in single-family zoning districts, subject to a statewide 1,000 sq ft size cap and minimum setbacks. The ADU itself is permitted through the standard Residential Building Permit process.