76-2-215. Accessory dwelling units -- regulations -- restrictions, MCA

Montana Code Annotated 2025

TITLE 76. LAND RESOURCES AND USE

CHAPTER 2. PLANNING AND ZONING

Part 2. County Zoning

Accessory Dwelling Units -- Regulations -- Restrictions

76-2-215. Accessory dwelling units -- regulations -- restrictions. (1) (a) In jurisdictional areas where the board of county commissioners has established zoning regulations under this part, the regulations must allow a minimum of one accessory dwelling unit by right on a lot or parcel that contains a single-family dwelling.

(b) An accessory dwelling unit may be attached, detached, or internal to the single-family dwelling on a lot or parcel.

(2) A county may not:

(a) require that an accessory dwelling unit match the exterior design, roof pitch, or finishing materials of the single-family dwelling;

(b) require that the single-family dwelling or the accessory dwelling unit be occupied by the owner;

(c) require a familial, marital, or employment relationship between the occupants of the single-family dwelling and the occupants of the accessory dwelling unit;

(d) assess impact fees on the construction of an accessory dwelling unit;

(e) require improvements to public streets as a condition of permitting an accessory dwelling unit, except as necessary to reconstruct or repair a public street that is disturbed as a result of the construction of the accessory dwelling unit;

(f) set maximum building heights, minimum setback requirements, minimum lot sizes, maximum lot coverages, or minimum building frontages for accessory dwelling units that are more restrictive than those for the single-family dwelling on the lot;

(g) impose more onerous development standards on an accessory dwelling unit beyond those set forth in this section; or

(h) require a restrictive covenant concerning an accessory dwelling unit on a parcel zoned for residential use by a single-family dwelling. This subsection (2)(h) may not be construed to prohibit restrictive covenants concerning accessory dwelling units entered into between private parties, but the county may not condition a permit, license, or use of an accessory dwelling unit on the adoption or implementation of a restrictive covenant entered into between private parties.

(3) Nothing in this section prohibits a county from regulating short-term rentals as defined in 15-68-101.

(4) A county may require a fee for reviewing applications to create accessory dwelling units. The one-time application fee may be up to $250 for each accessory dwelling unit. Nothing in this section prohibits a county from requiring its usual building fees in addition to the application fee.

(5) A county that has not adopted or amended regulations pursuant to this section by October 1, 2025, shall review and permit accessory dwelling units in accordance with the requirements of this section until regulations are adopted or amended. Regulations in effect on or after October 1, 2025, that apply to accessory dwelling units and do not comply with this section are void.

(6) The provisions of this section do not supersede applicable building codes, fire codes, or public health and safety regulations adopted pursuant to Title 50, chapter 2.

(7) (a) A county may require an expedited sanitation review as allowed in subsection (7)(b).

(b) The department of environmental quality shall provide for a 15-day expedited sanitation review under 76-4-130 for an accessory dwelling unit that is being added to a parcel with existing public water and wastewater service that has capacity for the accessory dwelling unit.

(8) Nothing in this section prohibits a county from adopting regulations that are more permissive than the accessory dwelling unit provisions provided in this section.

(9) For the purposes of this section:

(a) "accessory dwelling unit" means a self-contained living unit on the same parcel as a single-family dwelling of greater square footage that includes its own cooking, sleeping, and sanitation facilities and complies with or is otherwise exempt from any applicable building code, fire code, and public health and safety regulations adopted pursuant to Title 50, chapter 2;

(b) "by right" means the ability to be approved without requiring:

(i) a public hearing;

(ii) a variance, conditional use permit, special permit, or special exception; or

(iii) other discretionary zoning action other than a determination that a site plan conforms with applicable zoning regulations;

(c) "county" means a county that exercises zoning powers under this part;

(d) "gross floor area" means the interior habitable area of a single-family dwelling or an accessory dwelling unit; and

(e) "single-family dwelling" means a building with one or more rooms designed for residential living purposes by one household that is detached from any other dwelling unit. (Subsection (7) terminates September 30, 2029--sec. 4, Ch. 619, L. 2025.)

History: En. Sec. 1, Ch. 619, L. 2025.