Commerce City residents can now build Accessory Dwelling Units (ADUs) following the 2025 update to the city’s Land Development Code. ADUs are smaller, self-contained living spaces located on the same property as a single-family home. They can be attached to the main house, created inside an existing space like a basement or garage, or built as a separate structure in the backyard.
ADUs give homeowners more flexibility. They can be used to house family members, provide space for caregivers, or create a long-term rental opportunity, all while keeping the character of existing neighborhoods. Only one ADU is allowed per single-family lot, and the ADU must remain secondary to the primary home in size and design.
Building an ADU requires meeting zoning and building code standards to ensure safety, access, and compatibility with surrounding properties. This includes limits on size and height, shared utilities with the main home, required setbacks from property lines, and safety features such as proper exits and fire protection. Before applying for permits, homeowners must also contact the city’s GIS Department to obtain a unit designation, which officially identifies the ADU in city records…