ADUs are allowed in MattoonTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Mattoon, IL
Is your property eligible for an ADU?
# of Properties
200
Owner-occupied
70%
Zoning districts
12
Avg Home Value
$47,167
Median Lot Size
0.25 acres
Avg Income
$72,779
Residential Types:
200 housing units
Apts (4+ units)
1%
Other
100%
Zoning Districts:
8,409 parcels · 12 districts
R1
66%(5,558)
C3
12%(1,045)
R3
7%(579)
R2
6%(522)
Other
8%(705)
ADU Rules
What can you build in Mattoon, IL?
Mattoon, IL 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
- –Maximum size must be smaller than the floor area of the largest primary dwelling unit (proxied by the home’s gross floor area for single-family).
Detached ADU Size Limits
- –Maximum size of 900 sq ft
- –Must be smaller than the floor area of the largest primary or principal dwelling unit (applied when the site has a single dwelling unit)
Owner Occupancy
- –Owner must reside in either the principal dwelling or the ADU
Rental Restrictions
- –Special-use ADUs: occupancy limited to owner's blood or marital relatives; non-family rental prohibited; caregiver occupancy allowed only if not paying.
- –Short-term rentals (<30 days) require a special-use permit and STR standards; not permitted in industrial districts.
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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Learn the key rules and size limits for ADUs