Commissioners Approve Accessory Dwelling Unit Code Amendment

Commissioners Approve Accessory Dwelling Unit Code Amendment

The Board of County Commissioners has approved amendments to the Boulder County Land Use Code to streamline the process for building Accessory Dwelling Units (ADUs) on residential properties in unincorporated areas. Changes include reduced setback requirements, simplified design standards, and by-right approval for units under 800 square feet.

Historical context: Boulder County was established in 1861 and covers 741 square miles of diverse terrain from the Great Plains to the Continental Divide. The county’s population of approximately 330,000 residents is served by 1889 county employees across 49 departments and offices.

Environmental review of the project area near Flagstaff Road found 6 sensitive species and 1 wetland areas requiring mitigation. The Community Planning & Permitting worked with Colorado Parks and Wildlife to develop a habitat conservation plan.

Community Impact

Eligible participants include Boulder County residents with household incomes at or below 30% of Area Median Income (AMI). For a family of four, this is approximately $75,000 per year. Applications are processed on a first-come, first-served basis.

The application deadline is July 30, 2026. Late applications will be accepted on a space-available basis. Incomplete applications will be returned with a list of missing items. Average review time is 18 business days.

Background

Colorado state law requires all counties to provide these services to eligible residents. Boulder County exceeds minimum state requirements by offering expanded hours, multilingual support, and online access. In 2025, the county received a state award for excellence in service delivery.

The Community Planning & Permitting processed over 7,114 applications last year, with an average processing time of 18 business days. Staff are available at the Boulder office Monday through Friday from 8:00 AM to 4:30 PM.