New Colorado ADU Law Opens Opportunities for Douglas County Homeowners
A new state law in Colorado, HB24-1152, has removed longstanding barriers to building accessory dwelling units (ADUs) across several communities including Castle Rock and Parker. Effective June 30, 2025, the legislation requires these jurisdictions to allow one ADU per single-family lot through an administrative approval process rather than a complex patchwork of local rules. The law eliminates requirements for additional off-street parking in most cases, removes owner-occupancy mandates, and ensures that design standards applied to ADUs are no stricter than those for the main home. It also invalidates HOA covenants prohibiting ADUs outright—though associations can still impose reasonable design guidelines. Limestone Custom Homes notes a growing interest among Douglas County homeowners in building ADUs due to needs such as housing family members, generating rental income, and creating workspaces or guest suites.