Frequently Asked Questions
Colorado ADU answers.
Does Colorado have a statewide ADU law?
Not a statewide one — HB 24-1152 (2024) only covers "subject jurisdictions": local governments over 1,000 residents inside one of Colorado's five Metropolitan Planning Organizations. Those jurisdictions had to update their ordinances by June 30, 2025, a deadline that has now passed, to allow one ADU per single-family lot through administrative review. Local zoning, building, utility, site, and private-covenant requirements may still apply; verify the current rules for the property before design or construction.
Does every Colorado city have to allow ADUs?
No. HB 24-1152 only applies to "subject jurisdictions" within a Metropolitan Planning Organization above certain population thresholds. Rural counties and small towns outside an MPO, such as Garfield County, are not covered by the mandate, though some allow ADUs voluntarily anyway.
Does Colorado require ADUs to match the main house?
Most Colorado municipalities still require ADUs to match or complement the primary residence in materials, roof pitch, and exterior finish. This is different from states like Washington, which explicitly ban this kind of design-matching requirement.
Can my HOA block my Colorado ADU even though state law allows it?
Not outright, if your property is in a subject jurisdiction. HB 24-1152 specifically bars HOAs and planned unit developments in covered MPO-area jurisdictions from prohibiting ADU construction, requiring neighbor sign-off, or charging special ADU fees. HOAs do retain authority to enforce "reasonable" design standards — matching siding, roof pitch, setbacks, height limits, and lot coverage — and what counts as reasonable is still being tested in Colorado courts. Review your HOA documents and consult a Colorado real estate attorney if the language is ambiguous before spending money on design or permits.
How long does ADU permitting take in Colorado?
There's no statewide deadline — but HB 24-1152 requires subject jurisdictions to offer administrative (staff-level) review rather than a discretionary public hearing, which tends to be faster. Actual timing still varies with the local authority, project complexity, corrections, utilities, site conditions, and application completeness; confirm the current timeline with the specific city or county.
What is the cheapest ADU to build in Colorado?
A Junior ADU — a converted interior space within the existing home footprint — is typically the cheapest option at $45,000–$95,000. Garage conversions are the next most affordable at $90,000–$200,000, and often the most HOA-compatible detached-style option since no new structure is added.
Why is Boulder more expensive than Denver for ADU construction?
Boulder consistently ranks among the most expensive rental and construction markets in the country, driven by a severely constrained housing supply relative to demand. Fort Collins similarly runs above Denver, driven by Colorado State University student housing demand. This is a genuine, sourced market condition — not every Front Range city behaves like Denver.
What is the ROI on an ADU in Colorado?
The adopted Colorado one-bedroom planning range is $900–$1,650 per month, derived from the HUD FY2026 revised FMR market basket under ROI-CM-1.4. Payback is calculated from the homeowner's budget, ADU type, size, rent range, and a 30% operating-expense reserve. Property value uses a 15% national planning input with a 10%–20% uncertainty range; it is not a valuation.
Which parts of Colorado are covered by HB 24-1152's five MPO regions?
The five Metropolitan Planning Organizations are the Denver Regional Council of Governments (Denver metro), Pikes Peak Area COG (Colorado Springs), North Front Range MPO (Fort Collins/Greeley/Loveland), Pueblo Area COG (Pueblo), and the Grand Valley MPO (Grand Junction). Any city or county over 1,000 residents inside one of these regions is a subject jurisdiction under the law; areas outside all five, including most of Colorado's rural counties, are not directly covered.
Did every Colorado city meet HB 24-1152's June 30, 2025 deadline?
Most subject jurisdictions updated their ordinances by the deadline, since the law is now in full effect and its HOA/PUD override provisions took hold even earlier. Confirm your specific city or county's current ADU ordinance directly, since local implementation details — parking, setbacks, size caps — still vary jurisdiction to jurisdiction even where the core mandate applies.
