Updated regulations
Starting February 14, 2025, the City of Fort Collins regulations have changed to come into compliance with Colorado House Bill 24-1152.
ADUs will may now be permitted in every zone district, and may be approved by city staff. Find City Council's Ordinance here.
Exploring Your Idea: Accessory Dwelling Unit#
A detached ADU to the rear of a primary dwelling unit.
The City of Fort Collins is here to support you as you explore the idea of adding an Accessory Dwelling Unit to your property.
What is an Accessory Dwelling Unit?#
An attached ADU to the rear of a house.
An Accessory Dwelling Unit (ADU) is a small house or unit that is on the same property as a larger building.
An ADU:
- Contains everything someone needs to live in a home: a kitchen, bathroom and living area.
- Is on the same property or lot as another house, duplex or triplex.
- Is typically smaller than the primary dwelling unit and is located to the rear of the primary unit.
- Can be attached to a house or detached.
- May not be used as a short-term rental.
Can I build an ADU?#
- If your property is in the Poudre River 100-year floodplain, you may not add any dwelling units.
Is my property in this floodplain? Check our floodplain map. - If your property has one existing house, duplex or triplex on it, you may build one ADU.
- If a house, duplex or triplex is permitted in your zone district (but nothing is built yet), you may build one ADU along with one house, duplex or triplex.
- Otherwise, it will depend on your space requirements, utility requirements, and costs, including fees from several City of Fort Collins departments.
Ready to take a deeper dive? Click the button below to get more details.
Interested in other options?#
Learn more about other options for adding a second dwelling unit on your property that may be available to you.
What happens next?#
In order to be permitted to build an ADU, you will need to go the Development Review Process.