Accessory Dwelling Units

Subject jurisdictions must allow one accessory dwelling unit (ADU) where single family detached units are allowed. Subject jurisdictions must use an administrative approval process for ADUs, cannot require parking or owner occupancy (with limited exceptions), must allow certain ADU sizes and setbacks, and generally cannot otherwise restrict ADUs through design and dimensional standards that are more stringent than those that apply to single family homes in the same district. Requirements in the law also apply to planned unit developments (PUDs) and homeowners associations (HOAs) within subject jurisdictions. Please reference C.R.S. 29-35-402 through 405 and the below tools and documents for specifics and details.

Subject jurisdictions are required to report compliance with HB24-1152 (C.R.S. 29-35-402 through 403) by June 30, 2025. Instructions for reporting compliance are forthcoming. 

The ADU Fee Reduction and Encouragement grant program is created to provide grants to accessory dwelling unit supportive jurisdictions for activities that promote the construction of accessory dwelling units, including but not limited to, offsetting costs incurred in connection with developing pre-approved accessory dwelling unit plans, providing technical assistance to persons converting or constructing accessory dwelling units, or waiving, reducing, or providing financial assistance for accessory dwelling unit associated fees and other required costs.

DOLA anticipates launching the ADU grant program shortly after subject jurisdictions are able to become certified (June 30, 2025). Funding will also be available for ADU financing programs via CHFA. 

To be certified as an ADU-supportive jurisdiction, subject jurisdictions are required by the law to submit a report showing compliance and implementation of one or more strategies from a menu of strategies encouraging ADU construction or conversion. Local governments that are not subject jurisdictions can opt in to be eligible for the ADU grant program and for their residents to be eligible for the CHFA financing programs. Instructions on how to submit this report are forthcoming.

Under this law, nothing prevents a local government from applying the following policies and regulations for ADU construction or conversion: 

• Requiring a parking space be designated so long as there is an existing space available for designation, including a driveway, garage, or tandem parking, or other off-street space 
• Requiring one new parking space if an off-street space is not available, on-street parking is prohibited, and parking is required as of January 1, 2024 for the primary dwelling unit
• Requiring owner occupancy at the time of application either to construct/convert an ADU (except for new construction) or for a short-term rental license
• Allowing ADUs smaller than 500 square feet and/or larger than 750 square feet so long as the ADU is not larger than the principal dwelling unit
• Allowing multiple ADUs
• Assessing impact fees
• Regulating short term rentals 
• Applying historic district standards / procedures
• Applying life safety code (e.g., utilities, fire, stormwater)
• Defining ADUs to include motor homes, recreational vehicles (or not)
• Requiring a water / wastewater capacity letter 

• June 30, 2025: One-time compliance report due to DOLA for subject jurisdictions and those seeking to opt-in for certification as an ADU-supportive jurisdiction
• September 28, 2025: DOLA approves and certifies / rejects / grants extension

• Factory-built structure model code 
  (Under development by DOLA’s Division of Housing)
• Fee Reduction and Encouragement Grant Program 
  (For subject jurisdictions and those that opt in) 
  Anticipate launching grant program shortly after subject jurisdictions are able to become certified (June 30, 2025)
• ADU Toolkit (estimated timing May 2025)