The new Colorado state laws for Accessory Dwelling Units (ADUs) are primarily defined by HB24-1152, which significantly changes how these units are regulated across the state.

Key highlights of the new regulations include:

• Mandatory Allowance: The law requires most municipalities to allow attached, detached, and internal ADUs "by right" in residential zones. This ensures that local governments cannot outright prohibit the construction of ADUs.
• Implementation Timeline: Historically larger cities must comply by 2025, while all remaining jurisdictions must meet these mandates by 2026.
• Local Authority: While cities cannot ban ADUs, they still maintain control over local development codes. This includes regulations regarding setbacks, height limits, lot coverage, and parking requirements.
• Relaxed Restrictions: The new state mandates generally aim to relax previous barriers, such as reducing minimum lot size requirements and easing owner-occupancy restrictions in many areas.
• Building Requirements: Even with state-level changes, all ADUs must meet safety and habitability standards. For example, legal ADUs typically require a minimum ceiling height of 7.5 feet for habitable rooms and must meet ICC code for egress windows (minimum 5.7 sq. ft. opening) to ensure life safety.