ADU Regulations in Grand Junction, Colorado
In Mesa County on Colorado's Western Slope, Grand Junction allows ADUs in lower-density single-family zones. Without a Colorado state ADU mandate, the city's 25% lot coverage limit and owner occupancy requirement are locally determined.
Below is a summary of the key zoning rules applicable to Accessory Dwelling Units in Grand Junction as of 2026. Regulations are governed by local zoning ordinances, as Colorado has no statewide ADU mandate (HB 24-1152 addresses transit density).
| Regulation | Requirement |
|---|---|
| Maximum Size | 1,000 sq ft |
| Property Setbacks | 5 ft rear, 5 ft side |
| Extra Parking Required | Required (1 space) |
| Owner Occupancy | Required |
Additional Local Requirements for Grand Junction
- ADU in lower-density single-family zones
- Minimum 200 sq ft
- Maximum 25% lot coverage
- Building permit required
- ⚠️ CO has NO statewide ADU mandate — verify with city
📥 Download the Complete Grand Junction ADU Cheat Sheet
Get the step-by-step permit checklist, official government forms, direct planning department contacts, and estimated fees — all in one printable PDF for Grand Junction, Colorado.
Download the Complete Grand Junction ADU Cheat Sheet — $12Frequently Asked Questions About ADUs in Grand Junction
Can I build an ADU in Grand Junction?
Grand Junction allows ADUs in single-family zones. Owner occupancy and off-street parking must be provided.
How big can my ADU be in Grand Junction?
What is the maximum ADU size allowed in Grand Junction? ADUs in Grand Junction can be up to 1,000 square feet, subject to the property's zoning and lot coverage limits. Always confirm the exact allowed size with the Grand Junction planning department before designing your project.
What about setbacks and other requirements in Grand Junction?
What are the setback requirements for an ADU in Grand Junction? ADUs in Grand Junction generally require setbacks of 5 ft rear, 5 ft side. California state law (AB 68) limits local setback requirements to 4 feet for existing structures, but always verify with local zoning.
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