Can I build an ADU on a single-family lot in Colorado?

In most urban jurisdictions, yes. House Bill 24-1152, effective June 30, 2025, requires local governments in urban areas to allow one accessory dwelling unit, through an administrative approval process rather than a discretionary hearing, on any lot zoned for a single-unit detached home, and bars owner-occupancy requirements and most added parking mandates. Rural and some smaller jurisdictions may fall outside the mandate, so confirm local applicability.

Does Colorado have home rule zoning?

Yes, for municipalities that have adopted a home-rule charter, including Denver, Colorado Springs, Boulder, Aurora, and Fort Collins — these cities set zoning independently of state statute. Statutory municipalities and unincorporated county land zone under state enabling law at C.R.S. Title 31, Article 23 and Title 30, Article 28, respectively.

Can a Colorado municipality limit how many unrelated people can live together?

No. House Bill 24-1007, the HOME Act, prohibits local governments from capping occupancy based on familial relationship statewide, effective July 1, 2024. Municipalities may still enforce occupancy limits based on health-and-safety code standards, such as building or fire code requirements.

How do I look up the zoning for a specific parcel in Colorado?

There is no single statewide parcel-zoning portal; zoning maps and parcel data are published separately by each municipality and county assessor. Home-rule cities like Denver publish interactive zoning map viewers directly.

Colorado · state zoning reference · Parcel data · lookup only

Colorado zoning: how it works and what you can build

Strong home-rule cities set their own zoning codes, but a sweeping 2024 state legislative package now forces ADU legalization, transit-oriented density, and a statewide ban on occupancy limits regardless of local preference.

How zoning works in Colorado

Colorado is a strong home-rule state: municipalities that have adopted a home-rule charter (Denver, Colorado Springs, Boulder, Aurora, Fort Collins, and dozens more) draw zoning authority directly from their own charters rather than state statute. Statutory (non-home-rule) municipalities zone under the state enabling framework at C.R.S. Title 31, Article 23, and counties zone unincorporated land under C.R.S. Title 30, Article 28. This split means zoning procedure and substance can vary meaningfully from one jurisdiction to the next, even between adjacent municipalities.

That local variation is now colliding with an assertive state legislature. In its 2024 session, the General Assembly passed a package of land-use bills that preempt local control on several fronts: HB24-1152 requires urban jurisdictions to allow one accessory dwelling unit through an administrative approval process, without a discretionary hearing, on any lot zoned for a single-unit detached home, and bars owner-occupancy mandates and most added parking requirements for ADUs. HB24-1313 requires municipalities that sit within a metropolitan planning organization, meet a population threshold, and contain qualifying transit-related acreage to set and demonstrate progress toward housing-density goals near transit corridors. HB24-1007 (the HOME Act) bans occupancy limits based on familial relationship statewide, leaving only health-and-safety-code-based occupancy caps in local hands.

For developers, the practical takeaway is that Colorado zoning research now requires checking two layers: the local zoning code (which still controls use, height, bulk, and most site standards) and a growing body of state law that overrides specific local restrictions on ADUs, transit-area density, and occupancy — with more state preemption bills introduced most sessions since 2023.

Who holds the zoning power

Land-use authority in Colorado is delegated by statute, not assumed — these are the acts a zoning ordinance in Colorado has to trace back to.

Municipal Planning and Zoning Law C.R.S. Title 31, Article 23: Grants statutory (non-home-rule) municipalities zoning authority, including zoning commissions and boards of adjustment.
County Planning and Building Codes C.R.S. Title 30, Article 28: Enabling authority for county planning commissions and zoning of unincorporated land.
Accessory Dwelling Units law House Bill 24-1152 (2024): Requires urban jurisdictions to permit one ADU on single-unit lots through an administrative approval process; effective June 30, 2025.
Prohibit Residential Occupancy Limits Act (HOME Act) House Bill 24-1007 (2024): Bans occupancy limits based on familial relationship statewide, effective July 1, 2024.
Housing in Transit-Oriented Communities House Bill 24-1313 (2024): Requires designated transit-corridor municipalities to set and track housing-density targets near transit.

Major cities and their codes

The enabling act sets the ceiling; the municipal code is what a project is actually reviewed against. The 7 largest Colorado jurisdictions and the codes they administer:

Colorado — municipal zoning codes
City	Zoning code
Denver	Denver Zoning Code Form-based code organized around six neighborhood contexts rather than traditional Euclidean districts.
Colorado Springs	Colorado Springs Zoning Code Home-rule city; large annexation history shapes a patchwork of planned-unit-development zones.
Aurora	Aurora Zoning Code Spans three counties, requiring coordination across multiple county assessor and infrastructure systems.
Fort Collins	Fort Collins Land Use Code Early adopter of form-based and context-sensitive standards ahead of the 2024 state ADU mandate.
Boulder	Boulder Zoning Ordinance Directly subject to HB24-1313 transit-density targets and long-running local growth caps.
Lakewood	Lakewood Zoning Ordinance Voter-approved growth limits (Ordinance 1780) interact with the new state density mandates.
Pueblo	Pueblo Zoning Code Lower-cost secondary market with more conventional Euclidean districting.

Recent reforms

State-level changes override or preempt what a local ordinance says — these are the Colorado reforms that move the numbers on a real site.

2024 HB24-1152 Accessory Dwelling Units Requires urban jurisdictions to allow one ADU by right on single-unit lots and bars owner-occupancy and most parking mandates.
2024 HB24-1313 Housing in Transit-Oriented Communities Requires Front Range transit-corridor municipalities to set and demonstrate progress on housing-density goals.
2024 HB24-1007 HOME Act Prohibits local occupancy limits based on familial relationship statewide, with narrow health/safety exceptions.

Parcel & GIS data

Colorado has no single unified statewide parcel viewer; parcel and zoning data are maintained at the county assessor level, with some layers aggregated through the state's Colorado Information Marketplace open-data portal.

Real parcel geometry is already loaded for Aurora and Denver — see the zoning-by-city section above for a live district-and-parcel lookup there. That is not the same as a cited feasibility report: Chicago is still the only jurisdiction with bulk standards, § citations and a generated massing scheme.

Zoning by city

The statute sets who may zone; the city's own code sets what you can build. One guide per Colorado city below, explaining the district codes that appear on its zoning map — 65 district codes across Colorado so far.

Colorado zoning — common questions

Can I build an ADU on a single-family lot in Colorado?: In most urban jurisdictions, yes. House Bill 24-1152, effective June 30, 2025, requires local governments in urban areas to allow one accessory dwelling unit, through an administrative approval process rather than a discretionary hearing, on any lot zoned for a single-unit detached home, and bars owner-occupancy requirements and most added parking mandates. Rural and some smaller jurisdictions may fall outside the mandate, so confirm local applicability.
Does Colorado have home rule zoning?: Yes, for municipalities that have adopted a home-rule charter, including Denver, Colorado Springs, Boulder, Aurora, and Fort Collins — these cities set zoning independently of state statute. Statutory municipalities and unincorporated county land zone under state enabling law at C.R.S. Title 31, Article 23 and Title 30, Article 28, respectively.
Can a Colorado municipality limit how many unrelated people can live together?: No. House Bill 24-1007, the HOME Act, prohibits local governments from capping occupancy based on familial relationship statewide, effective July 1, 2024. Municipalities may still enforce occupancy limits based on health-and-safety code standards, such as building or fire code requirements.
How do I look up the zoning for a specific parcel in Colorado?: There is no single statewide parcel-zoning portal; zoning maps and parcel data are published separately by each municipality and county assessor. Home-rule cities like Denver publish interactive zoning map viewers directly.

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The parcel layer lands in the order demand does. Illinois went first because that's where the deals were; the next state is decided by who tells us what they're trying to underwrite. Tell us where you're building and what you wanted to run — you'll hear from us when Colorado opens, and sooner if we need a test parcel.

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Want to see the finished shape of this work? Illinois is live at parcel level — Illinois zoning and the 53-district Chicago reference.

Colorado zoning summaries on this page are provided for information, not legal advice. Confirm every project against the current adopted code for the jurisdiction and the statute as amended.