ADU Regulations:
Walpole
Regulations Snapshot
Rear and Side setbacks: Follows underlying zoning, typically 30 feet
Building Separation: 10 feet
Height: 35 feet
Separate utilities required: Yes
Stormwater management: Follows underlying zoning
Specialized Stretch Energy Code: No
Impact Fees: $3-4k fee to DPW for water/sewer hookup
Building Constraints
Number of ADU’s allowed on a single family lot
One ADU allowed per single-family lot, whether interior, detached, or attached
Maximum square footage of an ADU (detached or attached)
Up to 900 square feet or half the gross floor area of the primary dwelling, whichever is smaller
Maximum Height
35 feet
Maximum lot coverage
Follows underlying zoning. Usually 40% for structural and impervious surfaces
Exterior appearance requirements
Must appear congruent with primary dwelling
Setbacks
Rear setback
Follows dimensions of underlying zoning of principal dwelling. Usually 30 feet
Side setback
Follows dimensions of underlying zoning of principal dwelling. Can vary from 10 to 25 feet.
Front setback
Follows dimensions of underlying zoning of principal dwelling. Usually 30 feet.
Distance between buildings
10 feet
Parking
Parking requirement for an ADU
One additional parking space is required for the ADU unless with a half mile of a transit station. There are no requirements for the location of the parking space on the property.
Where can the parking be located : Parking requirement for primary dwelling
2 parking spaces
Additional Requirements
Separate utilities required
Water and sewer must go directly to the main in the street. Electric must have its own service.
Stormwater management required
Based on underlying zoning
Town impact fees
Water/sewer fee through DPW, $3,000 - $4,000 fee for hookup
Soils report required
No soils report, inspect once dug. If they have questions at this point, they will ask for a report
Civil plans required
Yes, a full plot plan and civil utility connections and topography
Short term rental allowed
No
Possible overlay districts
Floor Plain Protection or Water Resource Protection zones could affect ADU permitting. Find links to maps here: https://www.walpole-ma.gov/zoning-board-of-appeals/pages/land-use-maps
ADUs on multifamily lots
Currently not allowed on multifamily lots