ADU rules in Taos

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.

Both guesthouse definitions require the unit to be 'within an accessory building located on the same lot and detached from the principal dwelling, located a minimum ten feet (10') from the principal dwelling', so a basement conversion, an internal unit or an attached addition cannot qualify as a guesthouse and Title 16 offers no other accessory-unit path. The R-1, R-2 and R-3 zones permit only one single-family dwelling per lot as a principal use. The R-4, R-6 and R-14 zones do permit a 'two-family attached or semiattached residence, such as a duplex, townhouse, condominium or apartment' as a principal use, but that is a second principal dwelling counted against the zone's density cap (4, 6 and 14 units per acre respectively), not an accessory unit, and R-4 expressly bars a guesthouse that would be accessory to a two-family attached or semiattached residence.

Both the plain guesthouse and the conditional-use 'guesthouse used for long term rental' are capped at a unit that 'shall not be greater in size than fifty percent (50%) of the heated floor area of the principal residence'. There is no absolute square-foot ceiling and Title 16 sets no separate height limit for guesthouses in the residential zones. The general accessory-use test in the same section is looser (an accessory must be less than 70 percent of the heated floor area of the principal structure), so the 50 percent guesthouse rule is what binds. Zone lot coverage is the other real constraint: 20 percent of the lot by all structures in R-1 and R-2, 40 percent in R-3 and R-4, and 5 to 15 percent in the RA zones. If a traditional neighborhood development plan is approved under Section 16.16.230, that district caps an 'accessory unit' (the code's own synonym for casita) at 440 square feet instead.

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.

The off-street parking table has no guesthouse or accessory-dwelling row. Section 16.20.040.2.C fills the gap: 'Where the parking requirements for a use are not specifically defined herein, the parking requirements for such use shall be determined by the code administrator; and such determination shall be based upon the requirements for the most comparable use specified herein.' The nearest rows are 'Residence, 1 bedroom and efficiency apartments 1.1 per unit' and 'Residence, single-family 2 per unit', so plan on roughly one added space and confirm the number with staff before you design. Outside the CBD and the historic overlay zone, off-street parking must be provided for any change of use, new construction or addition. If the unit is instead operated as a permitted short-term rental, the STR chapter is explicit: one space for a one-bedroom unit and two spaces for two or more bedrooms, or a minimum of one space per vehicle.

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.

The definition of 'Guesthouse' bars rental outright: the unit is for friends or relatives of the occupants of the principal dwelling and 'shall not be rented or otherwise occupied for monetary or other consideration'. The landlord version is 'Guesthouse used for long term rental', defined as rented 'for a period of thirty (30) days or more' and listed as a conditional use in the RA-20, RA-10, RA-6, RA, R-1, R-2, R-3, R-4 and CBD zones, so it takes a Planning and Zoning Commission hearing. Stays of 30 days or fewer fall under the Town of Taos Short-Term Rental Ordinance (Section 5.04.070, Ordinance 22-12, effective 10/1/2022): an annual permit is required, the Town issues no more than 120 at a time on a first-come first-served basis, permits run October 1 to September 30, are not transferable and terminate immediately on sale, and short-term rentals are prohibited in the historic districts, the historic and hotel overlay zones, the CBD, and in any unit sharing a common wall, floor or ceiling with another dwelling unit. That regime reaches only a 'dwelling unit, or portion thereof', and a guesthouse is by definition not a separate dwelling while its rentable form is defined as 30 days or more, so a Taos casita is not a lawful short-term rental; Section 5.04.070.6.C independently requires every STR to comply with the rules of its zoning district. Nothing in Title 16 contemplates selling a guesthouse separately: it must remain accessory to the primary residence on the same lot.