ADU Laws in Colorado (2026)
Colorado state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.
Law Name
Colorado House Bill 24-1152 — Accessory Dwelling Units · Verified June 25, 2026 · Source
Effective Date
2024-05-13
Preempts Local Ordinances
Yes — state law overrides local restrictions
Has State Law
Yes
Statewide ADU Preemption Applies
State law establishes statewide preemption standards that supersede local regulations. The citation and source below confirm the verified legal basis.
Key Provisions
Requires all Colorado municipalities with population over 1,000 to allow at least one ADU per single-family residential lot by-right · Source
Prohibits minimum lot size requirements specifically targeting ADU prohibition — local minimum lot size cannot exceed the zone's standard minimum · Source
Limits off-street parking requirements for ADUs — no additional parking required for ADUs within 0.25 miles of a high-frequency transit stop · Source
Requires ministerial (administrative) ADU approval — no discretionary design review for ADUs meeting objective standards · Source
Municipalities may not require owner-occupancy as a condition of ADU approval · Source
Creates a state enforcement mechanism through the Colorado Department of Local Affairs (DOLA) · Source
Municipalities had until July 1, 2025 to update their development codes to comply · Source
Applies to all counties with unincorporated areas with population over 1,000 as well · Source
Legislative History
2024 — Colorado HB 24-1152 · Verified June 25, 2026 · Source
Comprehensive ADU reform legislation signed into law May 13, 2024. Requires all Colorado municipalities over 1,000 population to allow ADUs by-right on single-family lots, removes minimum lot size barriers, limits parking mandates near transit, prohibits owner-occupancy requirements, and establishes state enforcement through DOLA. Local compliance required by July 1, 2025. · Source
2024 —
Companion middle housing legislation considered in the 2024 Colorado session. Alongside HB 24-1152, the legislature pursued broader efforts to expand missing middle housing options. No specific companion bill number is confidently identified here — see official source. · Source
Official Sources
What Does Preemption Mean for Local Cities?
Because Colorado law preempts local ordinances, individual cities cannot impose restrictions stricter than the state standard. A city may still have additional administrative requirements, but cannot deny ADU applications that comply with state minimums.
Learn about Coloradozoning preemption →Source: Colorado House Bill 24-1152 — Accessory Dwelling Units. Last verified April 5, 2026. View source