Which Colorado cities are not complying with the ADU law?
✓ Verified against code · August 19, 2026
Colorado's Department of Local Affairs identified roughly a dozen jurisdictions as non-compliant with HB24-1152 in an October 2025 compliance review — among them three Front Range cities this ledger covers in depth: Aurora, Arvada, and Thornton. Aurora's council rejected a staff-drafted compliance ordinance in June 2025 and still requires a public hearing instead of administrative approval. Arvada's August 2025 amendment left ongoing owner-occupancy, a blanket parking mandate, and a below-750-sq-ft size cap in place. Thornton's reenacted code kept ongoing owner-occupancy enforced by a recorded deed restriction. Greeley's code shows similar apparent conflicts but was notably not included on that same October 2025 non-compliance list.
Citation: DOLA compliance announcement (Oct 2025)
How current is this?
Colorado’s ADU rules run under HB24-1152 (2024). HB24-1152 (codified at C.R.S. 29-35-401 through 29-35-405) required every Colorado city or town of 1,000+ residents inside a metropolitan planning organization to allow one ADU wherever a single-family home is allowed, through administrative approval, by June 30, 2025 — banning ongoing owner-occupancy mandates (an at-application residency check is allowed), most new-parking requirements, and design standards that would block an ADU in the 500–750 sq ft range. Note the contrast with Washington: one ADU per lot, not two. We verified this answer against primary sources on August 19, 2026, and every change we catch is logged in the changelog.
More Colorado ADU questions
- What is HB24-1152?
- Does Colorado allow two ADUs per lot?
- What happened to Lakewood's zoning code?
- How big can an ADU be in Colorado?
- What is the 500 to 750 square foot size protection in Colorado's ADU law?
- Do Colorado cities require ADU owners to live on the property?
- Can Colorado cities require parking for an ADU?
- What does home rule mean for Colorado's ADU law?
- What do Colorado ADU permits cost?
- How long does it take to get an ADU permit approved in Colorado?
- Can I rent out my Colorado ADU short-term on Airbnb?
Not legal advice — local ordinances can go further than the state floor. The citation above points at the governing statute; check your city’s code for the specifics.