Accessory Structures in Fort Collins, CO (2026)
5 verified accessory structures rules for Fort Collins, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Fort Collins caps every lot at one accessory dwelling unit under City Code § 5-30's adoption of 2024 IRC Appendix BC. An ADU must sit inside an existing single-family detached home or townhouse, carry its own house number, stay secondary in size and function to the main dwelling, and meet the city's Land Use Code.
Fort Collins Accessory Dwelling Unit Rules
Some RestrictionsFort Collins City Code § 5-30 (2024 International Residential Code, Appendix BC § BC101.2, item 85)
BC101.2 Conditions. ADUs shall be permitted without requiring a change of occupancy where in compliance with all of the following: 1.An ADU shall be permitted within an existing single-family detached dwelling or within an existing townhouse unit that is within the scope of the International Residential Code.2.Only one ADU shall be permitted for each lot.3.An ADU shall have a separate house num...
ADU Impact Fees
Fort Collins charges capital expansion impact fees on accessory dwelling units before a building permit issues, billed on a discounted "Multifamily/ADU" square-footage tier under City Code Chapter 7.5. The community parkland fee alone runs $1,611 to $2,494 per ADU depending on size, on top of separate police, fire, and other capital expansion fees.
Fort Collins ADU Capital Expansion Fees
Some RestrictionsFort Collins Municipal Code § 7.5-28(a)
There is hereby established a community parkland capital expansion fee which shall be imposed pursuant to the provisions of this Article for the purpose of funding capital improvements related to the provision of community parks... Such fee shall be payable prior to the issuance of any building permit for a residential structure. The amount of such fee shall be determined per dwelling unit as f...
ADU Rental Restrictions
Fort Collins allows only one extra kitchen inside a single-family dwelling, and only through a minor amendment approval under Transitional Land Use Code Section 3.5.2(H). Before a building permit issues, the owner must record a notarized affidavit with Larimer County confirming the second kitchen will never be used to create a separate rental or second dwelling unit.
Fort Collins Second Kitchen ADU Restriction
Significant RestrictionsFort Collins Transitional Land Use Code § 3.5.2(H)
(H)Second Kitchen. A maximum of one additional kitchen may be established inside a dwelling unit without creating an additional dwelling unit if approved through a minor amendment pursuant to Section 2.2.10 and the following standards are met:(1)That both kitchens are accessible to all occupants of the dwelling unit;(2)That both kitchens have non-separated, continuous, and open access with no l...
Shed & Carport Rules
Fort Collins exempts small storage sheds from a building permit only if the shed is one story, 120 square feet or less, no taller than 8 feet, holds no more than 10 gallons of flammable liquid, and sits at least 3 feet from the property line.
Fort Collins Storage Shed Permit Exemption
Some RestrictionsFort Collins Municipal Code § 5-27 (2024 IBC Sec. 105.2, item 1)
1. One-story, detached, accessory structures used for lawn and garden equipment storage, tool storage and similar uses, including arbors, pergolas, and similar structures, provided that the floor area is not greater than 120 square feet (11 m2) nor greater than 8 feet (2.438 m) in height measured from grade, the structures do not house flammable liquids in quantities exceeding 10 gallons (38 L)...
Tiny Homes
Fort Collins has formally adopted Appendix BB Tiny Houses of the International Residential Code in full, giving tiny homes on foundations their own building-code path rather than forcing them to meet standard single-family dwelling rules.
Fort Collins Tiny House Building Standard
Some RestrictionsFort Collins City Code Sec. 5-30 (adopting 2024 IRC Appendix BB)
83.APPENDIX BA MANUFACTURED HOUSING USED AS DWELLINGS is adopted in its entirety.84.APPENDIX BB TINY HOUSES is adopted in its entirety.85.APPENDIX BC ACCESSORY DWELLING UNITS (ADU) is adopted in its entirety, and is amended to read as follows
Looking for Larimer County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Fort Collins city rules.
Accessory Structures in Larimer County →