ADU Parking Requirements in Boston, MA
ADU parking rules in Boston, Massachusetts. Required parking spaces, transit exemptions, and how to qualify for reduced parking.
Boston's Local ADU Ordinance
Unlike most Massachusetts municipalities, Boston operates under its own zoning charter with ADU-specific rules that may differ from the state baseline. This means some state-level rights may not apply in the same way. Check the specific rules below for Boston's requirements.
Transit Parking Exemption in Boston
Boston has transit stations, which means properties within 0.5 miles qualify for a complete parking exemption. This exemption applies to subway, commuter rail, bus rapid transit, light rail, and ferry terminal stations. Use our address checker to see if your property qualifies.
Meeting the Parking Requirement
To meet Boston's 1-space requirement, you can use existing driveway or garage spaces, create new on-site parking, or (if near transit) qualify for the exemption. Consider how the parking layout affects your ADU's size and placement on the lot.
How the Transit Exemption Works
The transit parking exemption in Boston is measured as a straight-line distance from your property to the nearest transit station entrance. If you're within 0.5 miles, your ADU has zero parking requirements. This can free up significant lot area for the ADU itself.
Important: State Baseline Data
The information on this page reflects Massachusetts state baseline rules. Boston may have additional local requirements. We recommend confirming with your local building department before starting your project.
Boston ADU Rules at a Glance
Max Size
1250 sq ft
% of Home
75%
Max Height
25 ft
Max Stories
2
Front Setback
25 ft
Side Setback
5 ft
Rear Setback
5 ft
Parking
1 space(s)
Approval
BY RIGHT
Owner Occupancy
Required
Rental Allowed
Yes
Short-Term Rental
Not allowed
Boston Building Department
Boston Inspectional Services Department
1010 Massachusetts Ave # 5, Boston, MA 02118, USA
Phone: (617) 635-5300
Frequently Asked Questions
Are there parking requirements for ADUs in Boston?
Boston normally requires 1 parking space(s) per ADU. However, if your property is within 0.5 miles of a transit station, you're exempt from all parking requirements. Boston has transit stations — check your specific address to see if you qualify for the exemption.
How do I know if I qualify for a parking exemption in Boston?
Use our address checker to see if your property is within 0.5 miles of a transit station in Boston. We calculate the distance from your exact address to the nearest station. If you're within the radius, you have zero parking requirements for your ADU.
Can I use existing driveway parking for my ADU in Boston?
In most cases, existing driveway or garage spaces can count toward Boston's parking requirement, as long as the spaces meet dimensional standards (typically 9 ft wide by 18 ft deep). Check with Boston's building department for specific requirements on parking dimensions and configuration.
Which transit stations qualify for parking exemptions in Boston?
All transit stations in Boston qualify for the parking exemption. Properties within 0.5 miles of any station — including subway, commuter rail, bus rapid transit, and ferry terminals — are exempt from ADU parking requirements.
Does tandem parking count for ADU requirements in Boston?
Tandem parking (cars parked one behind another in a driveway) may count toward Boston's ADU parking requirement, depending on local interpretation. This is a common question — confirm with Boston's building inspector before relying on tandem spaces.
What happens if I can't provide ADU parking in Boston?
If your property is near a transit station in Boston, you may be fully exempt from parking requirements. If you can't meet the parking requirement, options include applying for a variance, exploring shared parking arrangements, or choosing an ADU type (like a conversion) that may have different parking standards.
How accurate is the ADU data for Boston?
The information on this page reflects Massachusetts state baseline rules under the Affordable Homes Act. Boston may have additional local requirements that differ from the state baseline. We recommend confirming with your local building department before starting your project.
Where can I find all ADU regulations for Boston?
Visit our complete ADU rules page for Boston, MA for a full overview of zoning, permits, size limits, setbacks, parking, and costs. We cover all Massachusetts municipalities with data sourced from local ordinances and state law.
Check Your Address
See exactly what ADU rules apply to your specific property in Boston.