Littleton, CO Accessory Structures: ADU Rules (2026)

3, Land Use Matrix, and those qualifying ADUs can be approved administratively by the Director rather than through a public hearing. Before a building permit for the ADU is issued, the property owner must record a declaration of restrictions against the deed in the office of the County Clerk and Recorder; failing to comply with those restrictions is itself unlawful. The deed restriction has to state that the ADU cannot be sold separately from the principal dwelling, and the restriction runs with the land, binding any future owner.

Only one ADU of any type is allowed per lot, it must be a permanent, habitable structure, and manufactured homes, recreational vehicles and multipurpose trailers are barred from serving as an ADU. A lot carrying both a principal dwelling and an ADU cannot later be subdivided so that the ADU sits on a different platted lot than the primary home. ADUs in a historic district, or where the primary dwelling is a designated historic landmark, need additional Historic Preservation Commission review under Title 10, Chapter 8.

Once built, an ADU can be used the same way as a single-family dwelling, and the code specifically cross-references Title 3, Chapter 23, Short-Term Rentals, for any ADU an owner wants to rent out short-term.