Compare ADU rules across New Mexico

A detached second living unit is allowed in exactly one of Alamogordo's twelve zoning districts. Section 29-03-540.2(a)(2) lists among the permissive uses of the RE (Residential Estate) district 'accessory living quarters not exceeding one thousand two hundred (1,200) square feet and corresponding in architectural design with the primary dwelling unit.' Every other district bars it: the citywide accessory-building rule at 29-04-050(b) says 'no accessory building shall be used for a dwelling purpose,' and the R-1 rule at 29-03-070 repeats that 'no part of an accessory building shall be used for dwelling purposes,' which R-2, R-3, R-4 and MH-1 adopt by reference through their height regulations. RE demands a minimum lot of 32,685 square feet (0.75 acres) and the city's 2018 comprehensive plan puts RE at about 0.2 percent of Alamogordo's zoned land against 42 percent for R-1, so for almost every lot in town the answer is no.

Ordinance read August 2026

The code has no attached or internal ADU category at all. In R-1, the city's dominant district, 'a building or premises shall be used only for the following purposes,' and the residential entry is 'Single-family dwellings, they being buildings designed for occupancy by one (1) family' (29-03-010(1)), so converting part of a house into a separate independent unit turns it into a two-family dwelling, a use permitted only in R-3 and R-4. R-3 does allow a two-family dwelling outright, but as a duplex subject to a lot area of 6,000 square feet or 3,000 square feet per dwelling unit, whichever is greater (29-03-210), not as a subordinate accessory unit. In RE the accessory living quarters allowance is not written as detached-only, so an attached or internal version within the 1,200 square foot cap appears to qualify, although the code never defines 'accessory living quarters' and never says whether the quarters may contain a kitchen.

Ordinance read August 2026

The only second-kitchen path Carlsbad offers is a multi-generational dwelling, and it is family-only and non-rentable, so it is not an ADU in the ordinary sense. Section 56-31 defines it as a building designed for residential occupancy with up to two kitchens 'for use by any number of persons related by blood, common ancestry, marriage, guardianship or adoption', and expressly excludes 'a separate structure from the principal dwelling for the purpose of renting'. Use Table 1 row 1.g lists Multiple-Generational Dwelling as 'A', meaning allowed by right subject to a zoning permit, in R-R, R-1, R-2 and C-1, and leaves the C-2, I and PUD columns blank, which section 56-41(e) says means prohibited. The two-kitchen building stays one dwelling unit rather than becoming two: an ordinary single-family dwelling is defined as having 'only one kitchen', and no use category in Chapter 56 authorizes an independent rentable unit inside or attached to a house. This is Carlsbad's implementation of the state accommodation duty in NMSA 1978 Section 3-21-1(F), and it is more generous than the statute requires, since the statute is satisfied by a conditional use permit while Carlsbad grants the use by right.

Ordinance read August 2026

Clovis has a real ADU code, but in the districts where most houses sit it is not by-right. Table 30-1 marks 'Accessory dwelling unit' as a conditional use (C) in both single-family districts, RS-170 and RS-7, and in the CBD and I districts; it is permitted by right (P) only in RM (Residential Multi-family) and CG (Commercial General), and prohibited (-) in PI. Since a standard Clovis house is in RS-7 (7,000 sq ft minimum lot) or the large-lot RS-170, a typical backyard casita needs a conditional use approval decided by the City Commission after a Planning and Zoning Commission hearing. UDO 17.30.030.C.2.b adds a hard eligibility gate on top of the zone question: the lot must meet the district's minimum lot area and be occupied by a detached or attached house, and ADUs are barred outright on nonconforming lots. Only one ADU is allowed per lot.

Ordinance read August 2026

The UDO treats attached, internal and detached ADUs as a single use with a single row in Table 30-1, so an internal or attached unit carries exactly the same conditional use requirement in RS-170 and RS-7 as a detached one. UDO 17.30.030.C.2.e expressly authorizes four creation paths besides new detached construction: converting interior area of a house such as an attic or basement, adding floor area to an existing house, converting space inside a detached accessory building, and building a new house with an internal or detached ADU. There is no lighter ministerial track for a conversion, so a basement ADU in RS-7 goes through the same public hearings as a new backyard unit. One additional design rule bites only on attached and internal units: 17.30.030.C.2.g allows just one street-facing entrance on a house containing an ADU unless a second street-facing entrance predated the ADU, and detached ADUs are exempt from that rule.

Ordinance read August 2026

It turns on the zone. In RS-170, RS-7, CBD and I an ADU is a conditional use, and UDO 17.65.110 makes that a full discretionary process: the application is filed with the director of building safety, who prepares a report; notice is published in the newspaper fifteen days ahead and mailed to every owner within one hundred feet plus posted on site ten days ahead; the Planning and Zoning Commission holds a public hearing and recommends; then the City Commission holds its own public hearing and casts the final vote, and may attach conditions. In RM and CG an ADU is permitted by right with no hearing. In every district, UDO 17.30.030.C.2.j separately requires the director of building safety to review and approve plans for building and life safety code compliance before a building permit issues. Clovis operates its own certified Department of Building Safety, which also covers a five-mile extraterritorial jurisdiction and the City of Portales, so building permitting is local and the state Construction Industries Division is not involved.

Ordinance read August 2026

The Unified Development Code lists 'Accessory dwelling' as its own residential use in Table 5.1, and whether you can build one turns entirely on your zone. It is permitted by right (P) in the transect zones T2 (Rural), T3 (Neighborhood Edge), T4 (General Neighborhood) and T5 (Town Center) and in D2 and D2L (Medium Density Residential). It requires a special use permit (S) in R5 and R5L (Rural Density Residential, 5-acre minimum lots) and in D1 and D1L (Low Density Residential), which together cover most of the county's low-density unincorporated land. It is not listed at all, and so is not allowed, in the N (Natural), D3 (High Density Residential), DM (Mobile Home Park), MU (Mixed Use), commercial (C1 to C3) and industrial (I1 to I3) zones. A detached unit is an accessory building, so § 350-502B(10) bars it unless a principal building is permitted and already exists on the lot.

Ordinance read August 2026

The county draws no line between detached and attached: § 350-702 defines an accessory dwelling as 'a separate, complete unit with a separate entrance, kitchen, sleeping area, and full bathroom facilities, which is either attached or detached from the primary dwelling on the lot.' The same Table 5.1 row therefore governs an addition, a converted basement or an internal conversion, so the identical zone split applies (by right in T2, T3, T4, T5, D2 and D2L; special use permit in R5, R5L, D1 and D1L; not allowed in D3, DM, MU and the commercial and industrial zones). Article III's community-type track confirms internal units count, capping 'the habitable area of an accessory dwelling within the principal building or of an accessory building' at § 350-304F(2). The site standards tables set setbacks and height separately for principal and accessory buildings, so an attached or internal unit follows the principal-building rows while a detached casita follows the accessory-building rows.

Ordinance read August 2026

It depends on the zone. Where Table 5.1 marks the use 'P' (T2, T3, T4, T5, D2, D2L) the review is administrative: a detailed site plan under § 350-208A ('a detailed site plan shall be required for all uses and buildings,' with a licensed professional needed only for commercial, industrial and multifamily work) and a building permit from the county's own Building Services Division under § 350-210A. Doña Ana County runs a certified building department, so building permits are county-issued rather than issued by the state Construction Industries Division. Where Table 5.1 marks 'S' (R5, R5L, D1, D1L) a special use permit under § 350-204 is required first: the applicant may go straight to a Planning and Zoning Commission hearing, or the Zoning Administrator 'may administratively approve a special use permit if no written objections are received within 21 days' of posted, published and mailed notice to owners within 300 feet. Written objections in that window push the case to a P&Z public hearing. An approved SUP is recorded with the County Clerk, shown on the Official Zoning Map, and expires if the use has not commenced within, or is discontinued for, one year.

Ordinance read August 2026

Farmington calls its ADU an 'accessory apartment', and UDC Sec. 2.5.4.B lets it be either attached to or detached from the house. The gate is the district list: Sec. 2.5.4.A allows one accessory apartment per single-family dwelling only in the RE-2, RA, RE-1, RE-20, SF-10, SF-7 and SF-5 districts. Those are the estate and conventional single-family districts, so most Farmington homeowners qualify, but single-family homes are also permitted by right in SF-A, MF-L, MF-M, MF-H and SF-MH, and in those five districts no accessory apartment is allowed at all. One more gate: no lot may hold both an accessory guest house and an accessory apartment, and the approval runs for only five years at a time.

Ordinance read August 2026

The same Sec. 2.5.4 covers attached and internal units: 'Such apartments may either be "attached to" or "detached from" the principal single-family dwelling,' and Sec. 2.5.4.E confirms 'Apartments may have a kitchen.' The city's ADU page names garage and basement conversions as ordinary examples. The district limits of Sec. 2.5.4.A bite exactly as they do for a detached unit, so an attached unit is off the table in SF-A, MF-L, MF-M, MF-H and SF-MH. Do not confuse this with the attached 'guesthouse' of Sec. 2.5.8, which is allowed in every residential district but is not an ADU: it must have an open floor plan where the kitchen is not a separate room, and it may not be rented separately.

Ordinance read August 2026

A detached backyard ADU is allowed without a hearing, but only in seven residential zone districts: RA, RE, SFR-1, SFR-2, SFR-3, RM (RM-1 and RM-2) and MFR-L. Table 26 marks the Accessory Dwelling Unit row 'A' in those columns and leaves SFR-4, SFR-5, MHC, MFR-M, MFR-H and every mixed-use, non-residential and open-space district blank, which Sec. 16-12 says means the use is prohibited there; note 1 to the table spells out that ADUs are permitted in SFR-1, SFR-2 and SFR-3 and prohibited in SFR-4 and SFR-5. The ADU-eligible single-family districts are the larger-lot ones (minimum lot area 13,000 sq ft in SFR-1, 12,000 in SFR-2, 10,000 in SFR-3), so a great many Los Alamos townsite and White Rock lots zoned SFR-4 (8,000 sq ft) or SFR-5 (5,000 sq ft) cannot have one at all. Where allowed, a detached unit must stand at least ten feet from the primary dwelling and is held to the district's accessory-structure height limit: 15 feet in the SFR and RM districts, 20 feet in RA and RE, 12 feet in MFR-L. It also counts against the per-lot accessory-structure cap, which is three structures in the SFR and MFR-L districts, four in RM and five in RA and RE.

Ordinance read August 2026

Attached, internal and detached ADUs are the same use in Los Alamos County and share exactly the same zone gate, so an addition or a basement or interior conversion is available in RA, RE, SFR-1, SFR-2, SFR-3, RM and MFR-L and nowhere else. The Development Code defines an accessory dwelling unit as one that 'may be attached to the primary dwelling, contained within the primary dwelling, or built as a detached accessory structure and must contain a separate kitchen', and Sec. 16-18(a)(2) allows 'no more than one accessory dwelling unit either attached or detached per lot'. The same 250 to 800 sq ft window, the same one-parking-space rule and the same no-separate-sale rule apply. Because the definition ties an ADU to 'a primary single-family or two-family detached dwelling', an ADU is not available next to a townhouse, triplex, fourplex or apartment building even in RM and MFR-L where the row is marked 'A'. One practical difference: an attached or internal unit is part of the main building rather than an accessory structure, so it needs the building permit but not the separate accessory structure permit a detached unit requires.

Ordinance read August 2026

A detached ADU is a permissive accessory use, but only in four of the village's fourteen zone districts: A-R (Agricultural Residential), R-R (Rural Residential), R-1 (Single-Family Detached Residential) and R-M (Single-Family Detached Residential Mixed). Table 17.08.020(1) marks the 'Accessory dwelling unit' row (use code 17.100) with an 'A' in exactly those four columns and leaves R-2, R-3, R-4, C-1, C-2, M-1, M-2, SU, TOD-MU and TOD-R blank, and 17.08.010 provides that a blank cell means the use is prohibited in that district. The gate genuinely bites in R-2 (Single-Family Attached Residential), where a detached single-family house is a permitted primary use but no ADU may be added. Where allowed, 17.06.040 states that 'One accessory dwelling unit (ADU) shall be allowed' on the lot subject to the district setbacks and to 17.10.060(A), and 17.10.060(A)(5) expressly contemplates a detached unit; only an administrative development plan application is needed, with no hearing. Title 17 was rewritten wholesale by Ord. No. 481, adopted 1-30-2025 and effective 2-11-2025, which replaced the 2001 zoning code and created this ADU section.

Ordinance read August 2026

Attached and above-garage ADUs are treated identically to detached ones and carry the same four-zone gate. 17.10.060(A)(5) provides that 'An accessory dwelling unit may be detached, attached to or above a garage, or attached to or above a primary unit,' and 17.04.120 defines an accessory dwelling unit as a dwelling unit accessory to a primary single-family dwelling unit on a single-family lot containing living, sleeping, kitchen and bathroom facilities. The one design rule that shapes an internal or basement conversion is 17.10.060(A)(6): access through the primary dwelling is prohibited and pedestrian access must be independent, so a converted interior space needs its own exterior door. The seven-foot separation requirement in 17.10.060(A)(7) applies only to non-fire-rated detached structures and does not affect attached units. Los Lunas's code has no guesthouse or casita category: the pre-2025 code's terminology did not survive the rewrite, and any unit with a kitchen is simply an ADU.

Ordinance read August 2026

Roswell's zoning ordinance has no "accessory dwelling unit" category at all. The one ADU-like use is "multi-generational housing", and it is a special use in only three of the seven residential districts: R-S Rural Suburban (art. 6, § 2.B.17), R-VL Residential Very Low (art. 8, § 2.B.9) and R-L Residential Low (art. 10, § 2.B.4). A special use means a development-plan application and a public hearing before the Planning and Zoning Commission (art. 3, § 8), and the unit is limited to relatives and to under 400 square feet. In R-1, R-2, R-3 and R-4 the use is not listed, and art. 52, § 3.A allows only one principal building per lot outside R-3 and R-4, so the only detached second dwelling in those districts is the grandfathered allowance at art. 12, § 2.A.4 for lots whose dwelling was built before January 1, 2010 and sits 75 feet or more back from the front property line.

Ordinance read August 2026

The codified definition of multi-generational housing does not distinguish attached from detached, so an attached or internal unit under 400 square feet qualifies on the same special-use footing in R-S, R-VL and R-L; the adopting ordinance was explicit that "This housing may be an unattached, or attached to the primary unit" (Ord. No. 17-14, § 1.A, adopted 6-8-2017), wording Municode's codified text drops. Nothing in the code creates a general basement, garage or internal-conversion right: R-1 permits one "single-family detached dwelling per lot" (art. 12, § 2.A.1), and its only second-unit allowance, art. 12, § 2.A.4, requires a "second detached residential structure". Art. 50, § 2 note C counts a "half-story containing independent living quarters or apartment" as a full story for setback purposes, but that is a measurement rule, not a use permission.

Ordinance read August 2026

It turns entirely on the zone. A new multi-generational unit in R-S, R-VL or R-L is a special use: an application with a development plan, then a public hearing before the Planning and Zoning Commission, which may attach conditions and must find the use conforms to the city's land use plan (art. 3, § 8, as rewritten by Ord. No. 23-04 of 4-13-2023). The R-1 grandfather second structure at art. 12, § 2.A.4 is a permitted use, so it needs only staff review plus building permits. Building permits and inspections are run by the city's own Building Inspections office, with applications through the CloudPermit portal; accessory structures of 200 square feet or less that need no building permit still need a placement permit (art. 52, § 4.A.2.e). Since January 1, 2026 the state Construction Industries Division, not the city, issues electrical permits and does electrical inspections in Roswell.

Ordinance read August 2026

A backyard casita is possible in Ruidoso, but only in one zone and only after a hearing. Sec. 54-85(i)(1)a says accessory dwelling units 'are allowed only in the R-1 district and must receive conditional use approval,' and the R-1 district standards cap it at one: 'A maximum of one accessory dwelling shall be allowed per lot as a conditional use.' The Planning Commission decides the conditional use permit at a noticed public hearing and can attach conditions. Chapter 54 is the Land Development Code rewrite adopted by Ordinance 2024-08 on 1-14-2025 and codified in Municode Supplement 35; the January 2025 rewrite is what created the ADU category, which the prior code did not have.

Ordinance read August 2026

The code lists a single 'accessory dwelling unit' use with no attached-versus-detached split, so an internal or attached unit runs the same R-1 conditional use permit gauntlet. Two provisions narrow it sharply. Sec. 54-120 states that no 'cellar, garage, tent, trailer, basement with unfinished structure above, or accessory building shall at any time be used as a dwelling unit,' which closes off garage conversions and basement units as a route to a separate ADU; a finished home's basement may be used for living, eating, and sleeping only as part of the same household. And because an accessory building connected to the principal building by a roof or covered walkway 'shall be counted as part of the principal building' (Sec. 54-66 definition and Sec. 54-121(a)), a physically attached second unit tends to be reviewed instead as a two-family dwelling, itself a conditional use in R-1 under the Sec. 54-84 use table. Confirm the path with the planning administrator, who holds interpretation authority under Sec. 54-36(d).

Ordinance read August 2026

Not a strict owner-occupancy rule, but an ongoing on-site residency rule. Sec. 54-85(i)(1)c requires that 'the owner or long-term resident of the primary structure must live on site,' so the main house has to be somebody's actual home, either the owner's or a long-term tenant's; the owner does not personally have to live there. Combined with the ban on short-term renting an ADU, the effect is that a property owner cannot run both units as vacation lodging or leave the main house vacant while renting out the casita. The requirement is continuing, not just an application-stage attestation, and a conditional use permit may be revoked if its conditions are violated (Sec. 54-97(f)).

Ordinance read August 2026

Zoning approval is discretionary. Sec. 54-85(i)(1)a requires conditional use approval, and Sec. 54-97 routes that through a Planning Commission public hearing on a staff report, with approval requiring 'a two-thirds vote of the members of the planning commission present.' The commission may impose conditions and safeguards, may issue the permit for a fixed term with automatic cancellation and periodic review, and may revoke it for violations; a denied application cannot be refiled for six months absent new evidence. Separately, construction permits come from the Village itself, which operates its own building department under the 2021 IRC and IBC adopted in Sec. 22-31, not from the state Construction Industries Division.

Ordinance read August 2026

In the base zoning districts an ADU is processed as an administrative (ministerial) development permit: SLDC § 4.8.1 provides that 'a public hearing is not required' and § 4.8.2.1 requires a development permit for construction of any structure; the county quotes fifteen working days for standard residential permits with a $200 base application fee. Building trades inspections (foundation, framing, electrical, plumbing) and the certificate of occupancy run through the state Construction Industries Division, and the county application includes the state Multi-Purpose Building Application. In the Tesuque and Madrid community overlay districts, however, an ADU requires a discretionary conditional use permit under Chapter 4 (§§ 9.5.5.1, 9.6.5.1), and Los Cerrillos prohibits ADUs outright in its TC and PI overlay zones.

Ordinance read August 2026

Taos has no ordinance that uses the phrase 'accessory dwelling unit'; the operative use is the 'guesthouse', which by definition sits in a detached accessory building on the same lot. A guesthouse 'used only as an accessory to the primary residence' is a permitted accessory use in the RA-20, RA-10, RA-6, RA, R-1, R-2, R-3 and R-4 zones, and in the CBD as an accessory to a single-family residence; the R-6, R-14, ARO, C-1, C-2 and M-1 zones list no guesthouse use at all. In R-1 and R-2 the guesthouse and the principal dwelling must both be served by municipal or community water and wastewater (or hold a state variance for a private well and septic system) and must stand at least 20 feet apart. The catch is what the by-right unit may be used for: it is limited to friends or relatives of the people living in the main house, may not be rented for any consideration, and 'shall not be used as a separate dwelling'. A guesthouse anyone can actually rent is a different, conditional use ('guesthouse used for long term rental') requiring a Planning and Zoning Commission hearing in each of those same zones.

Ordinance read August 2026

No provision requires the property owner personally to live on the lot, but the by-right guesthouse is tied to the household in the main house: it may only be 'used or occupied by friends or relatives of the occupants of the principal dwelling', it 'shall not be rented or otherwise occupied for monetary or other consideration', and each zone allows it only 'so long as it is used only as an accessory to the primary residence'. That is an occupancy-linkage requirement that bites like a classic owner-occupancy rule. The conditional-use 'guesthouse used for long term rental' drops the friends-and-relatives limit and the no-rent rule and imposes no owner-occupancy or primary-residence test; the Short-Term Rental Ordinance likewise has none. New Mexico has no statewide ADU statute preempting any of this.

Ordinance read August 2026

Which track you are on depends entirely on whether the casita will be rented. A guesthouse that stays in the family is a permitted accessory use handled administratively: you file with the code administrator, who does the zone-district check and the building-code review and issues the building permit once the application is proper and complete, with plan review due within 15 business days. Renting it changes everything: 'guesthouse used for long term rental' is a listed conditional use, so the Planning and Zoning Commission must grant a conditional use permit after a noticed hearing, and it may do so only if the use will not create a danger to public health, safety or welfare, cause extraordinary public expense, or create a nuisance. Taos runs its own building department and adopts the New Mexico construction codes locally, so building permits come from the Town rather than the state Construction Industries Division, though state permits are still required for mechanical and electrical work. A guesthouse inside the La Loma Plaza or Taos Downtown historic districts also needs historic overlay design review.

Ordinance read August 2026