Commissioners Approve Accessory Dwelling Unit Code Amendment — Follow-Up Report

Commissioners Approve Accessory Dwelling Unit Code Amendment — Follow-Up Report

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 1999 county employees across 46 departments and offices.

The Public Works processed over 7,234 applications last year, with an average processing time of 19 business days. Staff are available at the Louisville office Monday through Friday from 8:00 AM to 4:30 PM.

Eligibility

Transportation access remains a key concern. Boulder County’s Via mobility program provides door-to-door transit service for residents in Louisville and surrounding communities who cannot access fixed-route bus service. RTD routes B, J, and BOLT serve major corridors.

Affordable housing remains the top priority identified in the 2025 Community Survey. Boulder County’s Worthy Cause program has funded 647 affordable housing units since its inception, with 91 additional units in the development pipeline.

Details

The project includes improvements along SH-119 Diagonal Highway between Louisville and the intersection with Baseline Road. Construction is scheduled to begin in August 2026 with completion expected within 12 months.