ADUs are allowed in JohnstonTypes:DetachedInternal
Types:DetachedInternal
Accessory Dwelling Unit (ADU) Rules for Johnston, RI
Is your property eligible for an ADU?
# of Properties
8,955
Owner-occupied
89%
Zoning districts
21
Avg Home Value
$380,431
Median Lot Size
0.26 acres
Avg Income
$102,361
Residential Types:
8,955 housing units
Single Family
93%
Apts (4+ units)
7%
Zoning Districts:
11,791 parcels · 21 districts
R-15
42%(4,996)
R-40
29%(3,424)
R-20
13%(1,585)
B-2
7%(770)
Other
9%(1,016)
ADU Rules
What can you build in Johnston, RI?
Johnston, RI 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
Owner Occupancy
- –No owner-occupancy; ADU occupant must be family member of principal occupant
Parking
- –2 spaces per dwelling unit; reductions only for four or more units (1.75 spaces/unit >1,000 ft from transit, 1.5 spaces/unit <1,000 ft); not applicable to three or fewer units; parking on/adjacent to the site; B-1 front-yard parking prohibited; off-street parking required at construction/enlargement.
Rental Restrictions
- –Accessory family dwelling unit path restricts occupancy to family of the principal resident, barring non-family rentals.
ADU State Law
What can you build in Rhode Island?
- –On an owner-occupied property as a reasonable accommodation for family members with disabilities;
- –On a lot with a total lot area of twenty thousand square feet (20,000 sq. ft.) or more for which the primary use is residential;
- –Where the proposed ADU is located within the existing footprint of the primary structure or existing accessory attached or detached structure and does not expand the footprint of the structure.
- –Subject to applicable dimensional requirements of the municipality
- –As per §45-24-38 of the RI Zoning Enabling Act, if an existing lot is smaller than the minimum lot size required by zoning, its setback requirements are reduced in proportion to the lot's size, and its maximum lot coverage is increased by the inverse proportion.
- –One ADU per lot
- –No short term rentals
- –Studio or 1 bedroom ADU may be up to 900 sq ft or 60% of the Gross Floor Area of the principal dwelling, whichever is less
- –2 bedroom ADU may be up to 1200 sq ft or 60% of the Gross Floor Area of the principal dwelling, whichever is less
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 Rhode Island municipalities
Rules change at the town line. Check the municipality your property is actually in.
Providence County