ADU Rules in Aurora, Colorado
Last updated: Verified:
Aurora is the third-largest city in Colorado and part of the Denver-Aurora metropolitan area. The city permits ADUs in residential zones under its Unified Development Code.
Permitted ADU Types
- Detached ADU: Standalone structure on the lot
- Attached ADU: Addition with own entrance and kitchen
- Garage Conversion: Converting existing garage
Size Limits
| ADU Type | Maximum Size |
|---|---|
| Detached ADU | 1,000 sq ft or 50% of primary dwelling |
| Attached ADU | 50% of primary dwelling floor area |
| Garage Conversion | Existing footprint |
Setbacks
- Front: Base zone standard
- Side: 5 feet minimum
- Rear: 5 feet minimum
Height
- Detached ADU: Maximum 20–24 feet
- Cannot exceed primary dwelling height
Parking
One additional off-street parking space required per ADU.
Permit Process
- Verify zoning: Contact Aurora Planning Division
- Submit plans: Architectural and site plans
- Plan review: Zoning and building compliance
- Building permit: Issued after approval
- Inspections and CO: Required before occupancy
Contact
Aurora Planning Division 15151 E. Alameda Pkwy, Aurora, CO 80012 Phone: (303) 739-7250 Website: auroragov.org/planning
Disclaimer: Verify current requirements with the Aurora Planning Division before starting any project.
More about Aurora Zoning
Sources
- City of Aurora — Unified Development Ordinance·auroragov.org·Accessed 2026-09-20·Direct link
- City of Aurora — 2024 Legislative Information: Accessory Dwelling Units·auroragov.org·Accessed 2026-09-20·Direct link
FAQ
Are ADUs allowed in Aurora, Colorado?
Yes. Colorado HB 24-1152 requires subject jurisdictions including Aurora to allow one ADU through an administrative process on lots where single-family detached dwellings are allowed. Check Aurora's current Unified Development Ordinance for the local implementation.
What is the current maximum ADU size in Aurora?
Do not rely on older Aurora summaries that stated a single 900- or 1,000-square-foot citywide cap. State law and Aurora's implementing UDO amendments govern the current standard, so verify the latest City code for the specific lot and ADU type.
Disclaimer: The information on this website is provided for general informational purposes only and does not constitute legal, financial, or professional advice. Always verify current requirements with your local planning department.