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ADU Zoning in Quincy, MA

Yes, you can build an ADU in Quincy — ADUs are approved by right under the Affordable Homes Act.

Complete ADU zoning guide for Quincy, Massachusetts. Learn about allowed ADU types, approval process, size limits, and local zoning regulations.

Data verified as of March 2, 2026
Researched — Some Fields Pending Verification

ADU Regulations in Quincy

Quincy follows the Massachusetts state baseline under the Affordable Homes Act. This means all Massachusetts state-level ADU rights apply — including by-right approval, no owner occupancy requirement, and standardized size limits. Quincy may also have additional local regulations that supplement the state baseline.

By-Right Approval: No Hearing Required

ADUs in Quincy are approved by right. This means you submit your building plans to the building department and receive a building permit without going through a public hearing or special permit process. By-right approval significantly reduces both the timeline and cost of your ADU project.

Allowed ADU Types

Quincy allows the following ADU types: detached, attached, conversion.

  • Detached — standalone structure in your yard, offering maximum privacy and design flexibility
  • Attached — shares a wall with your existing home, reducing construction costs and utility connections
  • Conversion — transforms existing space (basement, attic, or garage) into a separate dwelling unit

No Owner Occupancy Required

Quincy does not require owner occupancy for ADUs, a right guaranteed by the Affordable Homes Act. This means you can rent both your main home and the ADU, making it a viable pure investment property. You're also free to live in the ADU and rent the main house.

Historic District Considerations

Quincy has historically significant areas including Adams National Historical Park, Downtown Quincy Historic District, Faneuil Hall Marketplace, Quincy Historical Society & Museum, Quincy Quarries Reservation. If your property is located within or adjacent to a historic district, your ADU design may need to go through additional design review to ensure compatibility with the neighborhood's architectural character. This can affect exterior materials, rooflines, and window styles. Consult with the local historical commission early in your planning process.

Quincy ADU Rules at a Glance

Max Size

900 sq ft

% of Home

50%

Max Height

35 ft

Max Stories

2

Front Setback

25 ft

Side Setback

10 ft

Rear Setback

13 ft

Parking

1 space(s)

Approval

BY RIGHT

Owner Occupancy

Not required

Rental Allowed

Yes

Short-Term Rental

Not allowed

Quincy Building Department

Quincy Building & Zoning Department

55 Sea St, Quincy, MA 02169, USA

Phone: (617) 376-1450

Visit Website →

Frequently Asked Questions

Are ADUs allowed by right in Quincy, MA?

Yes. ADUs in Quincy are approved by right — you submit your plans to the building department and receive a building permit without a public hearing or special permit process. This is guaranteed by the Affordable Homes Act.

What types of ADUs can I build in Quincy?

Quincy allows detached, attached, conversion ADUs. With up to 900 sq ft allowed, a detached ADU gives you the most flexibility for a full living space.

Do I need to live on the property to build an ADU in Quincy?

No. Quincy does not require owner occupancy — this is a right guaranteed by the Affordable Homes Act. You can rent both your main home and the ADU, making this a pure investment property if you choose.

How big can I build an ADU in Quincy, MA?

In Quincy, you can build an ADU up to 900 square feet or 50% of your home's living area, whichever is larger. With 900 sq ft, you have enough room for a full 2-bedroom cottage with a kitchen, bathroom, and living area. This is guaranteed by the Affordable Homes Act.

Does Quincy have historic district rules for ADUs?

Yes. Quincy has historically significant areas including Adams National Historical Park, Downtown Quincy Historic District, Faneuil Hall Marketplace, Quincy Historical Society & Museum, Quincy Quarries Reservation. If your property is in or near a historic district, your ADU design may require review by the local historical commission for architectural compatibility. This can affect timelines and design choices.

Can I rent out my ADU in Quincy?

Yes, long-term rentals are allowed for ADUs in Quincy. However, short-term rentals (like Airbnb) are not currently allowed for ADUs. With a population of 101,636, Quincy has strong rental demand.

Check Your Address

See exactly what ADU rules apply to your specific property in Quincy.