ADU rules in Alamogordo

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.

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.

The single ADU size cap in the Alamogordo code is the 1,200 square feet that 29-03-540.2(a)(2) sets for RE accessory living quarters, which must also correspond in architectural design with the primary dwelling unit. RE caps accessory building height at twenty-five (25) feet (29-03-540.3(f)) against thirty-five (35) feet for the main dwelling, sets a three (3) foot side yard for accessory buildings (29-03-540.3(c)), and allows only one accessory building per 32,685 square feet (0.75 acres) under 29-03-540.3(a). No other district has an ADU size number because none permits the use. Where a genuine second unit is legal, in R-3 and R-4, it is built as a duplex or multifamily unit and is governed by lot area per dwelling unit (3,000 square feet in R-3, 2,000 square feet in R-4) rather than by any floor-area cap.

Nothing in Chapter 29 or anywhere else in the Alamogordo Code of Ordinances conditions a dwelling, an accessory building, or RE accessory living quarters on the owner living at the property. A full-text read of the code as codified through Ordinance No. 1718 (Supp. No. 58) turns up no owner-occupancy, resident-owner, or primary-residence language in any zoning provision, and New Mexico has no statewide ADU statute that would impose or forbid one. The binding constraint in RE is density rather than occupancy: 29-03-540.3(a) allows 'not more than one (1) single-family dwelling unit on any one (1) lot,' so the accessory living quarters cannot be carved off and sold separately without subdividing the lot.

The RE district imposes no numeric parking ratio. Section 29-03-540.3(h) says only that 'Off-street parking spaces must be provided' and that the number 'shall be sufficient to accommodate the number of vehicles that ordinarily are likely to be attracted to the development,' a performance standard staff applies at ordinance review rather than a countable requirement. Separately, 29-03-540.2(a)(1)b requires each dwelling unit in RE to have a private garage, at least 11 by 24 feet inside if attached and 20 by 24 feet if detached; the code never says whether accessory living quarters count as a 'dwelling unit' for that purpose, so confirm the point with Planning and Zoning before designing. Alamogordo's only numeric residential parking rules sit in districts that do not allow ADUs anyway: two spaces per dwelling unit in R-2 (29-03-180) and one space per unit for multiple dwellings in R-4 (29-03-240(i)), while R-1 states no off-street parking requirement at all.

Where accessory living quarters are allowed at all they are allowed by right: 29-03-540.2 lists them under '(a) Permissive uses,' not under '(b) Special uses (subject to conditional use permit),' which covers only golf courses, churches, utility facilities and schools. The process runs through two agencies. City Planning and Zoning performs an 'Ordinance Review' for zoning compliance (application form EG262, revised 02/28/2024, charging $75 for accessory buildings or carports and $75 for new residential construction or additions), and the building permit itself is issued by the State of New Mexico Construction Industries Division, because as the city's Planning and Zoning page states, 'The City of Alamogordo no longer has Building Inspectors.' In the other eleven districts there is no administrative path at all: 29-01-070(a) defines a variance as a dispensation of 'the dimensional regulations' only, so no use variance exists and the sole route to a second unit is a rezoning under 29-01-020 or a planned unit development under 29-03-541.

Chapter 29 contains no rental language of any kind; the word 'rent' does not appear anywhere in the zoning chapter, so there is no long-term rental prohibition and no primary-residence test. Alamogordo also has no short-term-rental regime: a full-text read of the code as codified through Ordinance No. 1718 returns no short-term rental, vacation rental, or transient-lodging section, and the 2016 attempt to create one (Ordinance No. 1523, proposed as section 29-04-130 with a $100 permit and a fire inspection modeled on Santa Fe's) never reached the code. A general business registration of $35 applies to any business carried on in the city (17-01-030), and stays under 30 days attract state gross receipts tax and the city's lodgers' tax, which the city collects but has not codified in Chapter 23. Because the underlying use must be lawful first, renting RE accessory living quarters to a separate household runs into the unresolved question of whether the quarters may be an independent dwelling at all, given that 29-03-540.3(a) permits only one single-family dwelling unit per lot.