Colorado ADU Laws, Costs & Permit Guide (2026)
Colorado passed statewide ADU legislation in 2024, requiring most municipalities to allow ADUs. Denver has an established ADU program with dedicated permitting resources.
Colorado ADU At a Glance
Permit Timeline
90–150 days
Average Build Cost
$130,000 – $280,000
Maximum Size
Varies by city (Denver: up to 1,000 sq ft detached)
Owner-Occupancy Required
Not required under HB 1152 (2024)
Impact Fees
Varies by city
Setbacks
Varies; Denver requires 5 ft rear setback
Recent Law Changes in Colorado
Required most Colorado municipalities to allow at least one ADU on single-family lots and prohibited owner-occupancy requirements.
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Browse Colorado Contractors →Frequently Asked Questions — ADUs in Colorado
Does Colorado require cities to allow ADUs?
Yes. HB 1152 (2024) requires most Colorado municipalities to allow ADUs on single-family lots and prohibits local owner-occupancy requirements.
How much does it cost to build an ADU in Colorado?
Colorado ADU costs typically range from $130,000 to $280,000 for a detached unit. Denver tends to run on the higher end. The state's ADU Finance Program offers low-interest loans for income-eligible homeowners.
Sources
Disclaimer: The information on this page is provided for general informational purposes only and does not constitute legal, financial, or construction advice. ADU regulations change frequently — always verify current rules with your local planning department and consult a licensed professional before making decisions. ADUHomeResource.com is not liable for any errors, omissions, or outcomes resulting from use of this information.