ADUs are allowed in Unincorporated MesaTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Unincorporated Mesa, CO
Is your property eligible for an ADU?
# of Properties
24,869
Owner-occupied
72%
Zoning districts
39
Avg Home Value
$371,091
Median Lot Size
0.25 acres
Avg Income
$82,838
Residential Types:
24,869 housing units
Single Family
3%
Apts (4+ units)
1%
Other
96%
Zoning Districts:
34,879 parcels · 39 districts
AFT
37%(13,031)
PUD
22%(7,785)
RSF-4
18%(6,381)
RMF-8
9%(2,997)
Other
13%(4,685)
ADU Rules
What can you build in Unincorporated Mesa, CO?
Unincorporated Mesa, CO follows state and local rules for Accessory Dwelling Units. Here is a concise overview of the local rules.
Eligibility
- –Internal / Attached ADU: By Right
- –Detached ADU: By Right
Interior / Attached ADU Size Limits
- –On lots smaller than 0.5 acre, an internal accessory dwelling unit may be up to 900 sq ft.
- –On lots at least 0.5 acre and less than 1 acre, an internal accessory dwelling unit may be up to 1,200 sq ft.
- –On lots 1 acre or larger, an internal accessory dwelling unit may be up to the greater of 1,500 sq ft or 50% of the principal home’s heated living area.
Detached ADU Size Limits
- –Maximum ADU size of 900 sq ft on lots up to 1/2 acre.
- –Maximum ADU size of 1,200 sq ft on lots over 1/2 acre and under 1 acre.
- –On lots 1 acre or larger, the maximum ADU size is the greater of 1,500 sq ft or 50% of the principal dwelling’s heated living area.
Max Units
- –Single-family detached: 1 ADU/lot (attached or detached).
- –Duplex or multifamily: 0 ADUs.
Owner Occupancy
- –No owner-occupancy required; manager if owner doesn't occupy.
Parking
- –1 space per bedroom (ADU); on-site parking only on same lot; off-site parking not allowed for residential (guest parking allowed); principal dwelling must have 2 spaces; driveways may be used for principal dwelling parking.
Rental Restrictions
- –Short-term rentals must be under 30 days; vacation rentals require Site Plan Review and a local property manager available. If neither unit is owner-occupied, rentals shall not occur when the local representative is unavailable.
ADU State Law
What can you build in Colorado?
- –ADUs must be approved based on objective standards; no discretionary hearings allowed.
- –Historic properties: Local historic review may still apply in designated historic districts.
- –Exempt parcels: ADUs are not required to be allowed on parcels without adequate water/sewer, in floodways, or on certain historic properties.
- –HOAs cannot prohibit ADUs: HOA rules that conflict with the state ADU law are void.
- –Parking exceptions exist: In rare cases, one parking space may be required if there is no existing off-street parking and on-street parking is prohibited.
- –Local rules still matter: Building code, fire code, utility capacity, and life-safety standards still apply.
- –More permissive is allowed: Municipalities may allow larger ADUs, multiple ADUs, or additional housing types beyond what the state requires.
- –Local zoning controls whether ADUs are allowed at all.
- –HOA rules may still apply.
- –More permissive local rules are allowed.
What's allowed on your lot?
These are the municipality-wide rules. What's allowed on a specific property also depends on state laws, setbacks, floor area ratio, lot coverage, environmental constraints, topography, and other property-specific factors. Search your address on FutureLot to see what's allowed on your property.
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ADU rules in other Colorado municipalities
Rules change at the town line. Check the municipality your property is actually in.
Mesa County