ADU rules in Los Lunas

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.

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.

17.10.060(A)(2) applies both limits together: 'Accessory dwelling units shall not exceed forty percent of the gross floor area of the primary dwelling unit and are capped at a maximum size of one thousand square feet.' The percentage test is the binding one on ordinary lots; a 1,800 sq ft house yields a 720 sq ft ADU, and the primary dwelling has to reach 2,500 sq ft before the flat 1,000 sq ft cap governs. On height, a detached ADU 'shall be no taller than the primary dwelling unit on the property' (A)(4), inside each district's 30-foot maximum building height in A-R, R-R, R-1 and R-M. Setbacks are the base district's own setbacks (A)(3), not the reduced accessory-structure setbacks in 17.10.060(B)(4), which by their terms apply only to structures not used for dwelling purposes.

No owner-occupancy condition appears anywhere in Title 17. A full-text check on 2026-08-04 of the codified title and of the adopted Ord. No. 481 PDF found no owner-occupied, resident-owner, principal-residence or reside-on-the-property language in 17.10.060(A), in the district standards, or in the development plan procedures. 17.10.060(A)(9) points the other way: 'Accessory dwelling units may be rented and/or occupied by persons unrelated to the occupants of the primary dwelling unit.' This is a purely local choice, since New Mexico has no statewide ADU statute; NMSA 1978 §3-21-1(F), as amended by Laws 2026, ch. 62 (SB 96, effective 7-1-2026), only requires zoning authorities to create a mechanism allowing up to two kitchens in single-family districts. If the ADU is short-term rented, the permit requires a named local owner or operator reachable twenty-four hours a day, but that person is not required to live on the property.

17.10.060(A)(8) states flatly that 'No additional off-street parking is required for accessory dwelling units,' and Table 17.12.010(1) confirms it by listing 'Accessory dwelling unit: No requirement' in the residential block. The primary dwelling keeps its own obligation (2 spaces for a single-family detached home, 3 if it has more than 3 bedrooms), so building an ADU does not shrink or expand that. Short-term rental operations cross-reference the same table through 17.10.060(I)(1)(ii), which means an ADU run as an STR also carries no added parking minimum, though the STR permit itself must state the maximum number of vehicles allowed to park on the property.

Administrative, with no public hearing. Table 17.08.020(1) marks the ADU with an 'A', which 17.08.010 defines as 'permitted as a permissive accessory use,' so no conditional use permit, designated use permit or variance is involved. What is required is a Development Plan Application under 17.14.020(E)(4), which Table 17.14.020(1) places under 'Administrative Decisions (no hearing required)' with the Community Development Department making the decision and the Development Review Committee reviewing; the village's form for this is the 'Development Plan Application, Residential Projects (Primary/Accessory).' A pre-application meeting with community development is mandatory before any application is filed (17.14.020(B)(1)). Keep zoning approval separate from building permitting: Los Lunas runs no building department, so the New Mexico Construction Industries Division issues the structural, mechanical, electrical, plumbing and gas permits, performs those inspections, and issues the final certificate of occupancy.

17.10.060(A)(9) expressly allows an ADU to 'be rented and/or occupied by persons unrelated to the occupants of the primary dwelling unit,' with no minimum lease term and no family-relationship test. Short-term rentals, defined in 17.04.120 as stays of less than thirty consecutive days, are themselves a permissive accessory use in all four ADU-eligible zones under Table 17.08.020(1) (use code 17.220), and the village's Short Term Rental Permit Application lists 'Accessory Dwelling Unit' as an eligible structure type, so an ADU may lawfully be the STR unit. The permit is administrative and approved by the community development director, costs $100, must be renewed on or before December 31 each year (late after January 31), is not transferable and terminates on sale of the property, and must be paired with a village business registration plus lodgers' tax and gross receipts tax payment. Two substantive limits: no more than two STR units directly adjoining each other on a residentially zoned street, and occupancy capped at two persons age three or older per legal bedroom. The code is silent on selling an ADU separately from the primary dwelling; because each A-R, R-R, R-1 and R-M lot is limited to one primary dwelling unit, a separate sale would require a subdivision the district standards do not contemplate.