ADU rules in Whitefish

Whitefish City Code 11-3-1.B allows an ADU detached from the primary single-family dwelling, attached to it, or attached to a garage on the same lot. Since the Montana Land Use Planning Act rewrite (Ord. 26-06, now codified), every residential district from WA through WR-4 lists Accessory Dwelling Units as a permitted residential use (for example 11-2F-2 for WR-1), as does WT-3, while the WB-1, WB-2, WB-3, resort residential, resort business, Big Mountain, WBSD, and WB-T districts list them when accessory to a single-family dwelling. 11-3-1 and the 11-9-2 definition still tie every ADU to a single-family home. Ord. 23-22 (10-16-2023) deleted the former 26-foot height cap for detached ADUs, and under 11-3-2.B a detached ADU is exempt from the 24-foot height limit that binds other residential accessory buildings.

Attached and internal ADUs are equally allowed. The 11-9-2 definition recognizes an Attached type (a unit attached to or located inside the primary dwelling, such as converted basements, attics, attached garages, and additions) alongside the Detached type (converted detached garages, new cottages, living space over garages), and 11-3-1.B covers units attached to the dwelling or to its garage. Only one ADU or guesthouse is permitted per lot, and the ADU must remain accessory to the primary single-family home.

11-3-1.B caps the ADU's interior habitable floor area at 1,000 square feet or 75 percent of the primary structure's gross floor area, whichever is less, the same ceiling MCA 76-2-345(1)(c) set while that statute bound the city. Ord. 23-22 (10-16-2023) raised the cap from the former 600 square feet (800 with a deed-restricted long-term lease) and deleted the old 26-foot, two-story limit for detached ADUs; a detached ADU is now exempt from the 24-foot accessory-building height cap (11-3-2.B) and follows the district's primary-structure height (35 feet in WR-1). Accessory buildings with a footprint over 600 square feet must meet primary-structure setbacks, while 600 square feet or less qualifies for reduced 6-foot side and rear setbacks under the district standards tables (for example 11-2F-4).

No owner-occupancy requirement appears in Title 11: not in 11-3-1, the 11-9-2 ADU definition, the district use lists, or the short-term rental standards (re-read via the American Legal API on 2026-10-23). Whitefish's SB 528 conformance ordinance (Ord. 23-22) left no such condition. Since the city completed its Montana Land Use Planning Act transition (Ord. 26-06, effective about 7-1-2026), MCA 76-25-105(4) exempts it from Title 76 chapter 2, so the owner-occupancy ban in 76-2-345(2)(c) no longer binds it directly and MLUPA's zoning part has no parallel ban; the answer now rests on the city code alone. Either unit may be rented while the owner lives elsewhere.

11-3-1.E states: "No off street parking spaces beyond what is required for the primary dwelling are required for the accessory dwelling unit." The 11-6-2 parking table, rewritten by Ord. 26-06 and now codified, carries an Accessory dwellings row reading "No required parking for the accessory dwelling unit" and sets residential parking at 1 space per dwelling unit with "no required parking for residential units under 1,200 square feet or deed restricted affordable housing". That matches MCA 76-25-303(1)(j) (HB 492, Laws 2025 ch. 682, in force since 10-1-2026), which bars a city under the Land Use Planning Act from requiring more than one space per dwelling unit or any parking minimum for residential units under 1,200 square feet. The former one-space ADU requirement was deleted by Ord. 23-22 in 2023 to meet MCA 76-2-345(2)(a), which no longer binds the city directly after its MLUPA transition.

ADUs are listed permitted uses in their districts (for example 11-2F-2) and are reviewed through a standard building permit; the city's ADU Quick Guide states a building permit must be obtained before starting construction or renovations, and no conditional use permit or public hearing applies. Converting existing space to an ADU without construction that needs a building permit calls for an administrative zoning compliance permit, which 11-7-9.B requires before a change in use when no building permit is required and which the zoning administrator decides within 20 business days of a complete application. The statutory by-right guarantee of MCA 76-2-345(1)(a) bound the city until its MLUPA transition; by-right review now rests on the city's permitted-use listings, and MCA 76-25-302(1)(e) names a permitted-use ADU among the Land Use Planning Act's housing strategies.

An ADU may be rented long term (11-3-1's stated purpose includes a supplemental income stream for owners of residential property), but it may never be sold separately from the primary home (11-3-1.C). Short-term rental, defined in 11-9-2 as stays of less than 30 days, is allowed only in districts whose use lists include it: the city's STR page names WB-3, WRR-1, WRR-2, WRB-1, and WRB-2, and the WBMV and WBMRR Big Mountain use lists also include short term residential rentals. 11-3-35 then requires an STR registration and business license (a 400 dollar annual application fee per the city), an annual fire inspection, a state public accommodation license, and monthly resort tax remittance, and 11-7-9.B requires a zoning compliance permit to change a residential use to a residential short-term rental. Operating outside an allowed district carries fines of 300 dollars for a first violation and 500 dollars for each later one, each day a separate violation, and advertising an unpermitted STR is itself evidence of a violation. Montana has no statewide STR preemption, so this local regime stands under the city's MLUPA zoning.