Compare ADU zoning rules across 3 Colorado cities. Average ADU score: 7.7/10.
| City | Max Size | Setbacks | Permit Fees | Build Cost | 1BR Rent | Score |
|---|---|---|---|---|---|---|
| Boulder | 800 sq ft (market-rate); up to 1,000 sq ft (affordable ADU program) | Confirm with Boulder Planning (reduced rear setbacks ~3 ft apply to market-rate detached ADUs near alleys) | $1,900-$3,200 | $160,000-$320,000 | $1,600-$2,100/mo | 8/10 |
| Colorado Springs | 50% of principal dwelling or 1,250 sq ft (whichever is less); 750 sq ft max if principal < 1,500 sq ft | 12 feet | $1,800-$3,000 | $130,000-$260,000 | $1,250-$1,700/mo | 7/10 |
| Denver | Up to 1,000 sq ft on lots over 7,000 sq ft (864 sq ft on 6,000-7,000 sq ft lots; ~650 sq ft on smaller lots) — varies by zone district | Must be within rear 35% of lot; 5 ft minimum rear setback | $500-$5,000 building permit + ~$2,055 Denver Water SDC (rising to $2,170 on Jul 1, 2026); total permit/utility typically $6K-$10K | $140,000-$280,000 | $1,400-$1,900/mo | 8/10 |
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