ADU Guide for Denver Homeowners

Why Denver Is the Most ADU-Friendly Market in Colorado

Denver has established ADU access across all residential zones, alley lots, and established carriage-house patterns — giving homeowners more flexibility than almost any other Colorado city. The city’s rules are specific though, and understanding them before hiring anyone saves significant time and money.

Denver’s ADU Rules

Denver requires ADUs to be positioned in the rear 35 percent of the lot and includes specific lot coverage rules and building form standards. The city also requires owner-occupancy at the time of ADU construction completion — though not as an ongoing requirement for long-term rentals. Permits are processed through Denver Community Planning and Development.

Denver permits up to 1,000 sq ft in some zone districts — larger than the 800 sq ft minimum required by state law. Side and rear setbacks cannot be more restrictive than those applied to other accessory structures.

Best ADU Types for Denver Properties

Detached Carriage Houses ($180K–$350K): Denver’s alley system makes rear-lot detached ADUs extremely practical. Many existing garages sit on alley lots and can be converted or replaced.

Basement ADUs ($40K–$110K): Older Denver bungalows often have high-ceiling basements ideal for conversion. The most cost-effective option in established Denver neighborhoods.

Garage Conversions ($45K–$130K): Converting a detached garage preserves lot space while creating a fully independent unit. Requires separate utility connections and egress windows.

Short-Term Rental Rules

Denver requires a short-term rental license and owner-occupancy for Airbnb/VRBO use. Long-term rentals (30+ days) are generally permitted without additional licensing. Check Denver’s current STR rules before designing your ADU for short-term use.