Zoning & Size Limits
| Requirement | Boulder, CO | Colorado Springs, CO |
|---|
| Allowed Zones | All single-family and multi-family zones | Single-family residential zones |
| Max Size (Detached) | 800 sq ft (market-rate); up to 1,000 sq ft (affordable ADU program) | 50% of principal dwelling or 1,250 sq ft (whichever is less); 750 sq ft max if principal < 1,500 sq ft |
| Max Size (Attached) | Up to 50% of principal structure or 1,000 sq ft max | 50% of principal dwelling or 1,250 sq ft (whichever is less) |
| Max Height | 20-25 ft (detached, depends on roof pitch); confir | 16 ft (detached ADUs); 25 ft (converted garage ADU |
| Parking Required | Not required (no parking minimum for ADUs per Ordinance 8650 | No parking required (removed April 2025) |
| Owner Occupancy | Not required (removed by Ordinance 8650, eff. March 8, 2025; | Not required (removed April 2025, per CO HB 24-1152) |
Setback Requirements
| Setback | Boulder, CO | Colorado Springs, CO |
|---|
| Rear Setback | Confirm with Boulder Planning (reduced rear setbacks ~3 ft apply to market-rate detached ADUs near alleys) | 12 feet |
| Side Setback | 3 feet | 5 feet |
| Front Setback | 15 feet | 20 feet |
Permits & Timeline
| Detail | Boulder, CO | Colorado Springs, CO |
|---|
| Permit Timeline | 40-60 days | 45-65 days |
| Permit Fees | $1,900-$3,200 | $1,800-$3,000 |
| Impact Fees | Minimal | $600-$1,200 |
| Pre-Approved Plans | Available | Available for select types |
Construction Costs
| Cost | Boulder, CO | Colorado Springs, CO |
|---|
| Avg Build Cost | $160,000-$320,000 | $130,000-$260,000 |
| Cost Per Sq Ft | $140-$280 | $130-$260 |
| Garage Conversion | $80,000-$180,000 | $65,000-$155,000 |
| Prefab ADU | $120,000-$270,000 | $95,000-$210,000 |
Rental Income Potential
| Rental | Boulder, CO | Colorado Springs, CO |
|---|
| 1BR Avg Rent | $1,600-$2,100/mo | $1,250-$1,700/mo |
| 2BR Avg Rent | $2,000-$2,800/mo | $1,600-$2,200/mo |
| Short-Term Rentals | Limited restrictions | Not typically permitted |
| Est. ROI | 6-8% annual return | 8-10% annual return |
Which City Is Better for ADUs?
Boulder scores 8/10 while Colorado Springs scores 7/10 on our ADU-friendliness index.
Boulder edges ahead overall. Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
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