ADU rules in Kalispell

Since Ord. 1950 (5-4-2026, the city's MLUPA and Land Use Plan Update), § 27.20.082(1) allows a second dwelling unit as a permitted use in any zone where a single-family dwelling is a permitted use, and the unit may be "a separate accessory dwelling unit", the detached backyard form. "Accessory dwelling unit" is listed as a permitted use in the R-1, R-2, R-3, R-5, RA-1, RA-2, H-1, and B-1 through B-4 district use lists, and § 27.20.080 exempts ADUs from the one-principal-structure-per-lot rule in R districts and from conditional use review for multiple structures in RA and H districts. An existing conforming or nonconforming accessory structure (a detached garage, for example) may be converted while keeping its existing setbacks (§ 27.20.082(3)(a)). Before 5-4-2026 the local code allowed a detached second unit by right only in B-1 through B-4 and only by administrative conditional use permit in R-4, R-5, RA-1, RA-2, and H-1 (R-1 got a guest house by CUP); the statewide mandate MCA 76-2-345 overrode those limits from 1-1-2024, and Ord. 1950 brought the printed code into line.

Kalispell reaches attached and internal second units through its duplex taxonomy: § 27.20.082(1) permits the second dwelling unit "as part of a duplex" in any zone where a single-family dwelling is permitted, and § 27.37.010 defines a duplex as two structurally joined dwelling units with separate entrances, which covers additions and basement or internal conversions with their own entrance. Duplexes also appear as a standalone permitted use in every residential district list. The practical result matches MCA 76-2-345(1)(b), under which an ADU "may be attached, detached, or internal"; the label just differs. Note that the ADU-specific conditions of § 27.20.082(2) (1,000 sq ft cap, single-story height limit, no sub-30-day rentals) textually attach to the separate accessory dwelling unit form, while a structurally joined second unit is regulated as a duplex, including the single-family and duplex design standards of § 27.20.110.

§ 27.20.082(2)(b) caps the gross floor area of living space in an ADU at 1,000 square feet, and the § 27.37.010 definition requires the single-family dwelling on the parcel to be "of greater square footage", so the ADU can never match or exceed the main house. Height is tied to setbacks: (2)(a) limits an ADU to "a single story with a height of no more than 18 feet unless the setbacks for a principal structure are met, in which case the maximum building height for the district would apply", and (3)(a) requires every ADU to "meet the setbacks required for a principal structure unless an existing conforming or nonconforming accessory structure is converted". In practice a newly built ADU sits at principal-structure setbacks and may rise to the district cap (35 ft in R-1, R-2, R-3, and R-5; 45 ft in RA-1 and RA-2), while the one-story, 18 ft limit bites a converted garage or shed that keeps its existing, closer setbacks. An attached second unit taken as a duplex has no 1,000 sq ft cap. Kalispell has zoned under the Montana Land Use Planning Act since Ord. 1950 (5-4-2026), so the old MCA 76-2-345 size formula no longer binds it and the local cap is the operative rule.

Neither § 27.20.082 nor any other provision of the zoning ordinance requires the owner to live in either unit; a full-text scan of the codified ordinance finds no owner-occupancy condition on ADUs (the only "primary residence" language governs home occupations in § 27.20.060). Before Kalispell's 5-4-2026 transition to the Montana Land Use Planning Act, MCA 76-2-345(2)(c) affirmatively barred requiring owner occupancy of either the house or the ADU. Under that Act the ADU housing strategy at MCA 76-25-302(1)(e) would let the city limit ADUs to a lot with a single-unit dwelling "occupied as a primary residence", but Kalispell imposed no such condition.

The residential row of the § 27.24.050(7) parking table, rewritten by Ord. 1950 (5-4-2026), reads: "Single Family Residence, Accessory Single Family, Duplex, and Multifamily Units Under 1200 square feet: No parking required", while units over 1,200 square feet need 1 space per unit and deed-restricted affordable housing needs none. Because ADU living space is capped at 1,000 square feet, a Kalispell ADU never triggers a parking requirement. State law now backs this up: Kalispell zones under the Montana Land Use Planning Act, and since 10-1-2026 MCA 76-25-303(1)(j), as amended by HB 492 (Laws of Montana 2025, ch. 682), bars a local government from requiring "more than one parking space for each residential dwelling unit" or "any minimum parking requirement for ... residential units under 1,200 square feet", so the city could not reimpose ADU parking. One wrinkle: for parking calculations, gross floor area counts a basement with 7 ft clearance, code-compliant access, and a hard floor (§ 27.24.050(6)).

Since Ord. 1950 (5-4-2026), § 27.20.082(1) makes the second dwelling unit "a permitted use" wherever a single-family dwelling is permitted: no conditional use permit and no public hearing. Process is ministerial: minor site plan review under § 27.20.120(2) (two sets of working drawings submitted to the planning and building department to show zoning compliance, the same track as any single-family dwelling or duplex) plus a building permit through the city's permit portal. Before 5-4-2026 the printed code required an administrative conditional use permit for a separate ADU in the R-4, R-5, RA-1, RA-2, and H-1 zones; that requirement was void from 1-1-2024 under MCA 76-2-345(5) because the statute's "by right" definition (76-2-345(9)(b)) excludes conditional use permits, and Ord. 1950 removed it from the text.

§ 27.20.082(2)(c) states flatly that rental periods of less than 30 days are not permitted for the accessory dwelling unit, so an ADU can be a long-term rental but never a short-term one. Other dwellings can seek short-term rental approval under § 27.20.095, which requires an administrative conditional use permit with annual renewal, a life-safety inspection, a State of Montana public accommodation license through the Flathead City-County Health Department, and caps short-term rentals at 2% of residences across all R and RA zones citywide; the categorical ADU bar means an ADU cannot use that path. Montana does not preempt local short-term rental rules: the zoning limits Kalispell now operates under (MCA 76-25-303) say nothing about short-term rentals, and the former ADU mandate MCA 76-2-345(3) expressly preserved municipal STR regulation. The ordinance says nothing about selling an ADU separately from the main house.