Accessory Structures in Billings, MT (2026)
3 verified accessory structures rules for Billings, Montana, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Billings allows one accessory dwelling unit per residential lot by right in N1/N2 zones, by special review in N3, with owner-occupancy and size caps.
Billings ADU Permit Rules
Some RestrictionsSec. 27-1008(G)
G.Accessory dwelling units.1.Applicability.(a)Accessory dwelling units (ADUs) are permitted by right in the N1 and N2 zone districts and are allowed by special review in the N3 zone district.(b)Accessory dwelling units in applicable zones are permitted on any parcel where a single dwelling unit is permitted or currently exists.(c)The minimum lot size for a lot that has both a primary dwelling u...
ADU Owner Occupancy
Billings requires the property owner to live in either the main house or the ADU at least six months a year, with a recorded deed restriction.
Billings ADU Owner-Occupancy Rule
Some RestrictionsSec. 27-1008(G)(2), Billings Municipal Code
2.Ownership and occupancy.(a)The property owner shall live in either the primary or accessory dwelling unit, with one of the units serving as their principal residency for at least six months in a year. No third-party rentals shall occur in the owner-occupied unit.(b)The property owner shall record a deed restriction with the Yellowstone County Recorder requiring owner-occupancy of the property.
Shed & Carport Rules
Billings zoning caps detached accessory buildings like sheds and shops at 1,500 square feet once they pass 200 square feet, and bars building in a required setback or within 5 feet of another structure.
Billings Shed and Accessory Building Size Rules
Some RestrictionsSec. 27-1008
No accessory building shall be erected in any required setback nor within five (5) feet of any other building except as specified in this section. ... Detached buildings for accessory residential uses ... greater than two hundred (200) square feet in size shall not exceed the principal building first story gross floor area on the lot or one thousand five hundred (1,500) square feet, whichever i...
Looking for Yellowstone County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Billings city rules.
Accessory Structures in Yellowstone County →