ADU rules in Farmington

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.

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.

Sec. 2.5.4 sets no floor-area limit and no percent-of-house limit for an accessory apartment. What binds instead is Sec. 2.5.2.B: accessory uses must stay 'subordinate to the principal use and structure ... in terms of area, extent, and purpose,' and 'the total gross floor area of all accessory structures plus the total gross floor area of the primary structure shall not exceed forty percent of the lot size.' The city's ADU handout repeats that 40 percent figure. Height follows the district: 35 feet in RA, RE-2, RE-1, RE-20, SF-10 and SF-7, and 26 feet in SF-5, but a detached unit set at least ten feet from the house and built in the required rear yard is capped at 15 feet (Sec. 2.8.3.C(4)c and Sec. 2.8.3.D(2)c). No more than three accessory buildings are allowed on a residential lot, and the lot only has to meet the district's ordinary minimum area, with no extra land required for the second unit.

Sec. 2.5.4.G is flat: 'The resident of the single-family dwelling or the apartment must be the owner of record of the property.' The owner may live in either unit, but somebody on title has to live on the lot, so an investor cannot rent out both. The requirement is ongoing rather than a one-time application test: the permit expires after five years and the director renews it only after finding that 'the conditions existing at the time of issuance of the original permit have not materially changed.' No New Mexico statute preempts this; the state has no ADU legislation at all as of 2026-08-04.

Sec. 2.5.4.F requires 'One off-street parking space ... for each apartment, in addition to that required for the primary dwelling unit,' the space must sit on the same lot as the primary dwelling, and tandem parking is expressly allowed, so a second car stacked in the driveway satisfies it. Schedule A in Sec. 5.2.3, as amended by Ord. No. 2025-1373 (adopted 6-10-2025), sets the same ratio using the term 'accessory dwelling unit: 1 per accessory dwelling unit,' against two spaces for the single-family house itself. There are no transit or small-lot exemptions.

Sec. 2.5.4 opens: 'An apartment may be allowed as an accessory use to a single-family dwelling by administrative review.' The Planning Division's ADU handout confirms the route and lists the submittals: an Administrative Review application and a scaled site plan with dimensions, with no hearing before the Planning and Zoning Commission or City Council. Two wrinkles matter. First, the approval lasts up to five years and must be renewed; the owner must apply six months before expiry, and 'if the renewal has not been granted prior to the end of the five-year period the owner will be required to re-submit an application for a special use permit.' Second, Table 2.3 still marks 'Apartments accessory to primary residence' with an 'S' (special use, meaning a Commission hearing and Council vote under Sec. 8.9) in all twelve residential districts, an unreconciled conflict with Sec. 2.5.4; Sec. 2.3.1 routes accessory uses to Sec. 2.5, and the city's own published guidance follows Sec. 2.5.4, so administrative review is the operative process. Building, electrical, plumbing and mechanical permits are separate and come from the city's own Building Inspection Division, not the state Construction Industries Division.

Sec. 2.5.4.D allows the rental outright: 'Such apartments may be rented, but not sold, separately from the principal dwelling unit.' Because Sec. 2.5.4.G requires an owner of record to live in the house or the apartment, only one of the two units can go to a tenant. Short-term rental is a different story: the UDC's household living category (Sec. 2.7.3.C) covers tenancy 'arranged on a month-to-month or longer basis' and says shorter arrangements 'are not considered residential ... they are considered to be a form of transient lodging,' while the accommodations category (Sec. 2.7.3.A) captures 'dwelling units arranged for short term stays of less than 15 days.' Table 2.3 has no short-term rental row at all, and under Sec. 2.3.3 a blank cell means the use is not allowed; the only accommodation use reachable in the single-family districts is a bed and breakfast, which needs a special use permit (permitted by right only in RE-2) and caps any guest stay at 15 consecutive days. Farmington has no short-term rental licensing ordinance; the city's occupancy (lodgers') tax of five percent applies to lodging that is not the guest's primary residence, with an exemption once a stay or written agreement reaches 30 consecutive days.