⚠️ This information is for educational purposes. Always verify current regulations with the Boulder Planning Department before starting your project.
Boulder ADU Regulations at a Glance
Here are the key zoning rules for Accessory Dwelling Units in Boulder, Colorado. These regulations apply as of 2026.
| Regulation | Requirement |
|---|---|
| Maximum Size | 1,200 sq ft |
| Property Setbacks | 5 ft rear, 5 ft side |
| Extra Parking Required | Required (1 space) |
| Owner Occupancy | Required |
Additional Local Requirements
- ADU on lots 5,000 sq ft minimum
- Detailed design review process required
- Green building requirements apply
- Short-term rentals strictly prohibited
- Boulder has its own specific ADU ordinance
📥 Get the Complete Boulder ADU Cheat Sheet
To get the step-by-step permit checklist and the official local contacts, download the Complete Boulder ADU Cheat Sheet.
Download the Boulder PDF Guide — $12Frequently Asked Questions About ADUs in Boulder
Can I build an ADU in Boulder?
Yes, Boulder allows ADUs under Colorado state law and local zoning ordinances. [ADDITIONAL_FAQ_1]
How big can my ADU be in Boulder?
The maximum size for an ADU in Boulder is 1,200 square feet, subject to setback and lot coverage requirements.
Do I need a permit for an ADU in Boulder?
Yes, all ADUs require a building permit from the Boulder Building & Safety Department.
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