The short answer: Colorado ADU law (HB24-1152) requires larger communities in metropolitan planning areas to allow ADUs on lots with a single-unit home, using an administrative approval process with objective standards only. Covered jurisdictions cannot require owner occupancy, cannot require extra parking in most cases, and must allow ADUs of at least 500 to 750 sq ft. Subject jurisdictions had to comply and file a compliance report with DOLA by June 30, 2025 (extensions were available, to December 30, 2025), so by now the rules should be in local codes, though not every code is fully updated.
Last verified: October 5, 2026 ยท Written by the ADU Scope editorial team
Key fact: The Colorado Department of Local Affairs (DOLA) publishes a list of the Colorado communities the law applies to, including Denver, Boulder, Colorado Springs, Fort Collins and Pueblo. If your town is not on that list, the state mandate does not apply and local zoning decides.
Who Must Follow the Colorado ADU Law
HB24-1152 applies to what the law calls “subject jurisdictions.” According to DOLA, these are statutory and home-rule cities and towns with a population of 1,000 or more located within a Metropolitan Planning Organization (MPO) area. It also covers the portions of counties inside an MPO that are within a Census Designated Place of 40,000 or more people.
The practical consequence is that the mandate follows the Front Range and other metro areas rather than the whole state. Mountain towns and small rural communities outside an MPO are generally not covered, even if they are popular for second homes. Many of them have their own ADU programs, so absence from the mandate does not mean ADUs are banned.
Tip: Ask your planning department directly: “Is this jurisdiction a subject jurisdiction under HB24-1152?” It is a yes-or-no question, and the answer decides which section of this article applies to you.
What the Colorado ADU Law Requires Covered Jurisdictions to Allow
Under DOLA’s summary, subject jurisdictions must allow ADUs that are internal, attached or detached, provide complete independent living facilities, and sit on the same lot as a proposed or existing primary residence. The unit must include facilities for living, sleeping, eating, cooking and sanitation.
Size and setbacks
- Size: jurisdictions must allow ADUs between 500 and 750 sq ft. They may allow smaller units, or larger units up to the size of the primary dwelling.
- Side setbacks: cannot exceed those for the primary dwelling.
- Rear setbacks: cannot exceed five feet or the accessory building standard, whichever is greater.
- Lot size: cannot require a larger minimum lot area for an ADU than for a single-unit dwelling in the same zone.
The size language works as a floor, not a ceiling. A city that wants to allow 1,000 sq ft ADUs can do so, but one that caps at 750 sq ft is still compliant. That is why two compliant cities can produce different maximum sizes, and why you should look up the local cap before choosing a floor plan.
What the Colorado ADU Law Does Not Let Them Require
The law lists several common obstacles that covered jurisdictions can no longer impose on ADUs.
| Topic | Rule for subject jurisdictions |
|---|---|
| Owner occupancy | Cannot require owner residence in the main house or ADU, with limited exceptions (residency at the time of application, or for short-term rental licenses) |
| Parking | No additional parking required, unless all three apply: the zone required parking before January 1, 2024; no existing lot parking is available; and on-street parking is prohibited on that block |
| Architecture and landscaping | Cannot be more restrictive than for single-unit dwellings on the same lot |
| Public hearings | Not allowed, except in historic districts with Certified Local Government status |
| Subjective review | Review must rely on objective standards |
The parking exception is narrow because it requires all three conditions at once. Most lots will not meet it, so in practice parking is not a hurdle for ADUs in covered cities.
Attention: The owner-occupancy exceptions matter if you plan to rent short term. A city may require owner occupancy specifically to obtain a short-term rental license, even though it cannot require it for ordinary housing.
How Approval Works Under the Colorado ADU Law
ADU applications in covered jurisdictions must go through an administrative approval process that uses only objective standards. DOLA defines objective standards as benchmarks that allow decisions to be made consistently regardless of who makes them, without subjective judgments about plan consistency or area compatibility.
What this means in practice
- Staff reviews your application against written standards (height, setbacks, size, codes).
- If it meets them, it is approved without a public hearing.
- Neighbors do not get a vote, and the city cannot deny because the ADU is “out of character.”
The ADU must still meet adopted fire, building, utility and stormwater codes. Utility capacity is often the real obstacle on older lots, so confirm service early.
Fees, Short-Term Rentals and Grants
Fees. Jurisdictions may require payment of generally applicable development impact fees; DOLA does not describe any ADU-specific fee exemption, so budget for them. Do not expect a blanket exemption: Colorado’s law limits discrimination in fees but does not eliminate them.
Short-term rentals. Covered jurisdictions may regulate short-term rental use of ADUs and may require owner occupancy to obtain an STR license.
Grants. DOLA’s timeline set the Accessory Dwelling Unit Grant Program (ADUG) to launch on August 1, 2025; check DOLA for current funding and award status. Jurisdictions that adopt at least one of ten supportive strategies can be certified as “ADU-supportive,” which makes them eligible for ADUG funds. Round 3 of the grant program is open from September 28 to October 23, 2026, so check DOLA for the current status of funding before counting on it.
Colorado ADU law: HOAs, PUDs and the statute’s reach
HB24-1152 was signed on May 13, 2024 (Chapter 167) with a safety clause, so it took effect on signing. The signed act creates new sections numbered 29-35-101 to 105, while DOLA cites the same article as C.R.S. 29-35-401 through 405 under the current code numbering. If you are reading statute text, expect to see both.
Private restrictions are part of the picture. In jurisdictions that are subject to the law or certified as supportive, a homeowners association covenant that conflicts with the law’s ADU provisions is void, whether it was adopted before or after the law. Reasonable restrictions that do not effectively prohibit ADUs or add significant cost can survive. Planned unit developments cannot be more restrictive than the local government’s own rules. Our guide on whether your HOA can block an ADU compares states.
Colorado ADU law: lots and situations the mandate does not reach
Even inside a covered city, some lots are outside the mandate. According to the act and DOLA, these include parcels without water and sewer service or with an inadequate well, parcels in a floodway or FEMA 100-year floodplain, and certain historic properties. Read the statute’s exact wording for the historic exemption before you rely on it.
Local governments can still apply their own rules where the law leaves room. The act allows jurisdictions to:
- allow sizes outside the 500 to 750 sq ft range, or cap an ADU at the size of the main home
- allow more than one ADU per lot
- charge impact fees and require mitigation
- regulate short-term rentals of ADUs
- apply historic-district standards, building, fire, utility and stormwater codes, and deed restrictions for affordability
Colorado ADU law: what the statute does not say
Two gaps matter. First, we found no statewide maximum ADU size in the act; the size ceiling is a local decision, as long as the city also allows a unit in the 500 to 750 sq ft range. Second, we found no deadline in the act for deciding an ADU application. The only deadlines in the text are administrative, such as DOLA’s 90 days to review a jurisdiction’s certification report. Do not assume a 30- or 60-day clock the way California has; ask your city for its published review time.
We also looked for amendments to HB24-1152 passed in 2025 and 2026 and found none as of October 2026. Absence from our search is not proof, so check the Colorado General Assembly website for the current text.
Colorado ADU law: who actually receives the grant money
Many summaries imply that homeowners can claim grants. The program does not work that way. DOLA’s ADU Grant Program makes awards to local and tribal governments certified as “ADU supportive jurisdictions”. The money funds things such as pre-approved plans, technical assistance and fee waivers. It is not a direct payment to a homeowner, so do not budget a grant into your own project unless your city announces a specific incentive.
DOLA’s figures show the scale. About $1.6 million was available for fiscal year 2025-26, with a 25 percent local match. Round 1 (November 2025) awarded $889,525 to seven communities, and Round 2 (May 2026) awarded $603,942 to eight. Round 3 opens September 28 and closes October 23, 2026. The signed act also mentions a reimbursement ceiling of $15,000 per permitted ADU, but DOLA’s current page does not repeat it, so we do not treat it as a benefit to owners.
The Colorado Housing and Finance Authority (CHFA) lists three ADU finance programs: relending, credit enhancement and an interest-rate buydown. They are aimed at low- and moderate-income owners in supportive jurisdictions. CHFA’s page shows no amounts or deadlines, so ask the agency directly.
Frequently Asked Questions
Does Colorado’s ADU law apply to my town?
Only if it is a subject jurisdiction: a city or town of 1,000 or more in an MPO, or a covered county portion. DOLA publishes the list.
Can the city make me live on the property?
Not in covered jurisdictions, apart from limited exceptions tied to the application or to short-term rental licensing.
Is parking required?
Almost never. It requires three specific conditions at the same time.
How big can my ADU be?
Cities must allow 500 to 750 sq ft; many allow more. Check your local cap.
Is there a public hearing?
No, except in certain historic districts.
Next Steps
- ADU Laws by State: Where You Can Build in 2026
- Arizona ADU Law: What Cities Must Allow Under HB 2720
- Owner-Occupancy Rules for ADUs: Key States Compared
General information, not legal advice. Local rules vary and change; confirm with your planning department.
Sources: Colorado DOLA: Accessory Dwelling Units ยท HB24-1152 text ยท HB24-1152 (signed act) ยท DOLA ADU Grant Program ยท CHFA ADU finance programs