Boulder County is reviewing whether to allow accessory dwelling units more broadly in the unincorporated parts of the county. The review is a docket, DC-26-0002, authorized March 24, 2026, and the county's land use code update index lists it as a pending proposal. Status checked September 7, 2026: the docket appears on that index among the proposals currently in review.
Jurisdiction matters before anything else. County land use rules apply to unincorporated land, not to property inside cities and towns. If you're inside city limits, your municipality's rules govern, and this docket isn't about your parcel.
What an ADU is, and what the county allows today
An accessory dwelling unit is a second home on the same property as the main house, with its own kitchen, sleeping area and bathroom. It can be attached to the principal dwelling or freestanding, as the City of Boulder's ADU service page describes.
The county's March authorization memo identifies four categories of ADU that are currently allowed under county rules: Family Care Units, Agricultural Units, Historical Units and Disaster Recovery Units. The Disaster Recovery Unit is a pathway for properties where the principal home was destroyed in the Marshall Fire. You can read the authorization memo directly.
For the current text of the rules, use the county's Land Use Code landing page. The county notes there that the compiled code PDF is being updated and advises checking Exhibit A of Resolution 2026-011 in the meantime.
What staff put in front of commissioners on May 5
Staff presented an initial scope at a May 5, 2026 work session. The accompanying staff memo lays out options staff intend to explore. Translated into the questions a property owner would ask:
- Should whether a site has utility service, sits near transit, or sits close to a municipality factor into where new units are permitted? The memo raises all three as possible siting criteria.
- Should areas with known hazards be left out? Staff intend to explore steering additional housing away from land unsuitable for it.
- Should converting existing floor area be treated differently from building new floor area, and should attached and detached units be handled the same way? The memo raises that split in general terms.
- Is there a role for an affordable housing program that accessory dwellings could be encouraged or required to participate in? Staff say they intend to explore that possible collaboration with Boulder County Housing.
The memo also recounts earlier direction from commissioners to explore broader allowances on the plains rather than in the mountains. That direction is recorded in a dated memo as something to explore. It is not an adopted prohibition and does not settle a boundary line.
The estimated schedule
The memo says staff planned public-input events during this exploration phase to inform draft amendments. The county's estimated schedule puts code development and community engagement from May through September 2026, with an estimated Planning Commission hearing in October 2026 and an estimated commissioners' public hearing in November 2026. Those are months, not set dates, and the timeline entry lists no hearing logistics or comment deadline alongside them. The May 5 memo warns the timeline could stretch out or be split across more than one docket.
City of Boulder and state law are separate tracks
The City of Boulder made its own ADU changes, applying to any ADU proposed on or after March 8, 2025. That's a different jurisdiction and a different rule set from this county docket.
At the state level, HB24-1152 became law May 13, 2024, and its administrative-approval requirement for ADUs took effect June 30, 2025 for subject jurisdictions, defined as qualifying municipalities or qualifying census-designated portions of counties. It isn't blanket countywide permission, and whether it reaches a specific area is a question for the county, not something to assume either way.
How to follow DC-26-0002
- The docket page is the primary source for status and estimated hearing months.
- The listed docket contact is planner Cayley Byrne, [email protected], 720-564-2819.
- The county's land use code amendment news signup includes public meeting and hearing notices.
- Ask a Planner handles planning, building and zoning questions for unincorporated areas.