Colorado law now limits how far homeowners associations can go in restricting ADUs, especially where local zoning already allows them. An HOA may still apply reasonable architectural or design standards, but it cannot use its rules to effectively eliminate an ADU that state and local law otherwise permit.
For homeowners, that means ADU HOA rules in Colorado should be reviewed alongside city or county zoning rather than treated as a separate yes-or-no decision. A project may need both local permitting and HOA architectural approval, but the HOA’s authority is not unlimited.
Key Takeaways
- Colorado law limits HOA restrictions on ADUs in qualifying jurisdictions.
- An HOA cannot simply prohibit an ADU when the restriction conflicts with current state protections.
- Reasonable restrictions may still apply.
- A restriction is not considered reasonable if it unreasonably increases construction cost, effectively prohibits the ADU, or eliminates the ability to build one.
- Architectural review can still address materials, appearance, landscaping, placement, and similar design issues when the standards remain reasonable.
- Local zoning approval and HOA approval are separate processes.
- Older HOA covenants may contain ADU restrictions that are no longer fully enforceable.
- Homeowners should review declarations, bylaws, rules, architectural guidelines, and recent amendments before finalizing plans.
Can an HOA Ban an ADU in Colorado?
In many Colorado communities, not simply because it wants to.
HB 24-1152 added protections that limit HOA restrictions on accessory dwelling units in subject jurisdictions and ADU supportive jurisdictions.
The law states that provisions in an association’s declaration, bylaws, or rules cannot restrict creation of an ADU in ways prohibited by Colorado’s statewide ADU law. A conflicting restriction can be void as a matter of public policy.
This applies to restrictions adopted both before and after the law took effect, subject to the law’s reasonable-restriction exception.
That is important because many Colorado HOA communities were created long before ADUs became a major statewide housing issue.
An old declaration may say that only one dwelling is permitted on a lot.
That language does not automatically answer whether an ADU can be built today.
Local Zoning Still Comes First
Colorado HOA protections do not create an ADU right on every parcel in the state.
The local zoning framework still matters.
HB 24-1152 requires qualifying subject jurisdictions to allow one ADU as an accessory use to a single-unit detached dwelling wherever that type of primary home is allowed, using an administrative approval process. Those local-government requirements have applied since June 30, 2025.
Another Colorado provision states that an association generally cannot prohibit or restrict ADU construction when the local jurisdiction’s zoning laws would otherwise allow the use, subject to the provision’s effective-date and governing-document rules.
The practical sequence is therefore:
| Question | Who Usually Controls It? |
|---|---|
| Is an ADU allowed on the property? | City or county zoning |
| Maximum ADU size | Local zoning and state limits |
| Setbacks and height | Local zoning |
| Building safety | Building department |
| Exterior materials | HOA may have a role |
| Landscaping or screening | HOA may have a role |
| Permit approval | Local government |
| Architectural approval | HOA, if applicable |
A homeowner should verify zoning before investing heavily in HOA design submissions.
What Is a Reasonable HOA Restriction?
Colorado law does not eliminate every HOA requirement.
HB 24-1152 specifically preserves reasonable restrictions.
The signed law defines a reasonable restriction as a substantive condition or requirement that does not unreasonably increase the cost of construction, effectively prohibit the ADU, or extinguish the ability to construct one in compliance with state law.
That distinction gives HOAs room to regulate legitimate community design concerns while limiting rules that function as indirect bans.
For example, an architectural standard requiring compatible exterior materials may be easier to justify than a rule requiring an ADU to use unusually expensive custom stone on every elevation.
Whether a particular restriction is reasonable can depend on the actual effect it has on the project.
Architectural Review Can Still Apply
Many Colorado HOAs require Architectural Review Committee approval before exterior construction begins.
An ADU can fall within that process because it may change the appearance, massing, roof form, landscaping, fencing, or other visible features of the property.
Reasonable review topics can include:
- Exterior materials
- Paint colors
- Roof design
- Window placement
- Landscaping
- Fencing
- Screening
- Driveway changes
- Exterior lighting
An HOA should not use architectural review as a way to accomplish indirectly what it cannot lawfully prohibit directly.
A requirement that continually changes or makes the project financially impractical may deserve closer review.
Size Restrictions Need Careful Review
HOA guidelines sometimes include limits on the size of accessory buildings.
That can create confusion when an ADU is classified differently under local zoning.
For example, local zoning might allow an 800-square-foot detached ADU while an older HOA rule limits all “accessory structures” to 300 square feet.
The HOA rule should not automatically be assumed enforceable against the ADU.
Colorado law specifically limits restrictive design or dimensional standards that conflict with state ADU protections in covered communities.
Homeowners should ask the association how the rule is being interpreted under current Colorado law.
If necessary, obtain professional legal advice before redesigning the project solely to satisfy an older restriction.
Can an HOA Require Matching Materials?
Potentially.
A requirement that the ADU use materials compatible with the primary residence may qualify as a reasonable architectural standard if it does not make the project excessively expensive or impossible.
The problem arises when a design requirement becomes so burdensome that it effectively prevents construction.
Consider the difference:
| HOA Standard | Potential Concern |
|---|---|
| Use a compatible roof color | Usually limited impact |
| Use similar siding style | Often manageable |
| Add landscaping screening | May be reasonable |
| Require rare custom materials | Could substantially increase cost |
| Require a footprint too small to function | Could effectively prohibit ADU |
| Require placement where zoning cannot be met | Could eliminate feasibility |
The legal question is not simply whether the HOA has an architectural rule.
Old Covenants May Not Tell the Whole Story
Some declarations contain language recorded decades ago that restricts lots to a single dwelling or prohibits secondary residences.
Homeowners often stop their research when they find one of these clauses.
That can be a mistake.
Colorado’s 2026 Common Interest Communities guidance explains that, in subject jurisdictions and ADU supportive jurisdictions, certain HOA restrictions conflicting with state ADU protections are void as a matter of public policy, including provisions adopted before the 2024 law.
The document should still be reviewed.
It may contain other enforceable standards involving exterior design, maintenance, common areas, or construction procedures.
The key is separating an outdated prohibition from legitimate current architectural requirements.
HOAs and Cities Do Not Approve the Same Things
Receiving HOA approval does not give you permission to build.
Likewise, a city building permit does not automatically satisfy a private HOA review requirement.
These processes operate separately.
A homeowner could theoretically receive zoning approval and still need to modify exterior details for the HOA.
The reverse can also happen.
An HOA may approve the appearance of a detached ADU, but the city’s setback or lot-coverage rules may prevent that design from being permitted.
Coordinate the two processes before ordering materials or signing a construction contract.
What Documents Should You Review?
Before designing the ADU, request the most current version of the association’s governing documents.
Do not rely only on the original declaration.
Pay attention to the dates.
Colorado ADU law changed significantly in 2024 and 2025, so older board decisions may not reflect what an HOA can enforce today.
Frequently Asked Questions
Can an HOA charge an architectural review fee for an ADU?
Potentially. Whether a fee is permitted depends on the association’s governing documents and applicable law. A fee should be reviewed if it becomes unusually burdensome or appears intended to discourage ADU construction.
Can an HOA restrict ADU exterior lighting?
Potentially. Reasonable lighting standards aimed at glare, safety, or neighborhood compatibility may still apply if they do not effectively prevent the ADU.
Can an HOA control who lives in the ADU?
HOA occupancy restrictions must comply with current federal, state, and local law. A rule targeting ADU occupancy should be reviewed carefully before assuming it is enforceable.
Can an HOA require landscaping around a detached ADU?
Potentially. Screening or landscaping can be a reasonable architectural condition when it does not make the project impractical or unreasonably expensive.
Review the HOA Without Assuming It Has the Final Word
Colorado homeowners in HOA communities should still take architectural review seriously, but an HOA does not necessarily have unlimited authority to prohibit an ADU.
Current state law protects ADU development in covered communities while preserving reasonable association standards.
Start with local zoning, then review the association’s current declaration, bylaws, rules, and architectural standards.
If an HOA requirement affects the project’s size, placement, or cost, determine whether it is a normal design condition or whether it effectively prevents an ADU that Colorado law otherwise protects.
Understanding both sides of the ADU HOA rules in Colorado can help homeowners avoid unnecessary redesigns while still completing the approvals required before construction.