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Zoning Guide

ADU Rules in Denver, Colorado

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ADU Rules in Denver, Colorado

Denver has been a leader in ADU-friendly policy reform. The city has removed many barriers to ADU construction to address its severe housing shortage, including eliminating owner-occupancy requirements and streamlining permitting. Denver permits ADUs by right in most residential zones.

Permitted ADU Types

  • Detached ADU: A standalone structure on the same lot
  • Attached ADU: An addition to the primary home with its own entrance
  • Carriage House: A dwelling unit above a garage, common in Denver's older neighborhoods
  • Basement ADU: Converting an existing basement to a separate dwelling unit

Size Limits

ADU Type Maximum Size
Detached ADU 1,000 sq ft or 50% of primary dwelling
Attached ADU 1,000 sq ft
Carriage House 1,000 sq ft or existing footprint
Basement Conversion 50% of primary dwelling floor area

Setbacks

Setbacks in Denver vary by zone but typical standards:

  • Front: Must meet zone requirements
  • Side: 3–5 feet minimum
  • Rear: 5 feet minimum in most zones
  • Alley: ADUs facing alleys may have reduced setbacks

Height

  • Detached ADU: Maximum 24 feet in most zones
  • Some zones allow taller structures

Owner Occupancy

Denver eliminated its owner-occupancy requirement for ADUs. You may own the property without living there and still build and rent an ADU.

Alley Lots

Denver has numerous alley lots — detached ADUs facing alleys (carriage houses) are a traditional and popular Denver building type. These are permitted in most residential zones.

Permit Process

  1. Check zoning: Verify your zone at denver.gov/community-planning
  2. Design: Prepare architectural plans
  3. Submit online: Denver has an online permitting portal
  4. Plan review: Administrative/ministerial review
  5. Building permit: Issued after approval
  6. Inspections: Required at each phase
  7. Certificate of Occupancy: Required before occupancy

Contact

Denver Community Planning and Development 201 W. Colfax Ave, Denver, CO 80202 Phone: (720) 865-2974 Website: denvergov.org/community-planning

Disclaimer: Verify current requirements with Denver Community Planning and Development. Denver's ADU regulations have evolved rapidly.

More about Denver Zoning

Building Permits — Cost & TimelineSetbacks & Height Limits

Sources

  1. Denver Zoning Code — Accessory Dwelling Units·denvergov.org·Accessed 2026-04-07·Direct link
  2. Denver ADU Design Guidelines·denvergov.org·Accessed 2026-04-07·Direct link

FAQ

Are ADUs allowed in Denver, Colorado?
Yes. Denver has made significant efforts to streamline ADU construction. The city allows ADUs by right in most residential zones without requiring a public hearing or discretionary review.
What is the maximum ADU size in Denver?
In Denver, detached ADUs are limited to 1,000 square feet or 50% of the primary dwelling's floor area, whichever is less. Attached ADUs are limited to 1,000 square feet.
Does Denver require owner occupancy for ADUs?
Denver removed its owner-occupancy requirement for ADUs. Property owners are no longer required to live on-site to build or rent an ADU.