Provincetown, MA

Provincetown, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 10/10 (10 is most accepting)

Last updated: 6.6.2024

Image source: Frommers

What You Need To Know

ADU bylaws were recently updated in Provincetown. They now allow between two and four dwelling units on a single lot depending on your zoning district.

Type of ADU Permit Required

ADUs in Provincetown require a building permit, not a special permit.

ADU Rules

• ADUs per lot are dependent on your residential district

• Residential 1 Zoning District 

• No more than two dwelling units total

• Residential 2 Zoning District

• No more than three total dwelling units total

• Residential 3, B, TCC, and GC Zoning Districts

• No more than four dwelling units total  

• ADUs cannot be used for short term rentals.  Must be rented for a period greater than 31 days.

• Detached ADUs cannot be greater than 600 square feet.

• 40% of gross floor area if the ADU is located in the primary dwelling

• Parking requirements do not apply to ADUs.

Resources:

Town of Provincetown Zoning By-laws- Page 29

https://www.provincetown-ma.gov/DocumentCenter/View/762/Zoning-By-Laws-PDF?bidId=

Mashpee, MA

Mashpee, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 10/10 (10 is most accepting)

Last updated: 6.18.2024

Image source: Mashpee Commons

What You Need To Know

Accessory dwelling units are referred to as ADUs in Mashpee.

Type of ADU Permit Required

A building permit is required for an ADU.  

ADU Rules

• The property owner must reside in either the primary dwelling or accessory dwelling unit.

• It is possible to rent either the primary dwelling or the ADU; however, both cannot be rented at the same time.  Rental period may not be less than 30 consecutive days.

• Conservations commission, historic, and wastewater treatment requirements must be complied with.

• ADUs can be up to 900 square feet and cannot be less than 350 square feet.  

• ADUs can be within or attached to the existing dwelling or detached.

• There cannot be greater than two bedrooms in an ADU.

• The design of the ADU must be consistent with the existing dwelling.

• One off-street parking space must be provided for the ADU.

• ADUs cannot have their own driveway as new curb cuts are not permitted. 

Resources:

Zoning Bylaws of the Town of Mashpee, MA- Article 4/§174-45.4 A/Page 80

https://www.mashpeema.gov/sites/g/files/vyhlif3426/f/uploads/2023_zoning_bylaws_0.pdf

Orleans, MA

Orleans, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 10/10 (10 is most accepting)

Last updated: 6.18.2024

Image source: Cape Cod Life

What You Need To Know

Orleans, like many other towns on Cape Cod, have made amendments to their zoning bylaws to combat the growing need in the area for affordable housing. Still, there remains a number of rules that must be complied with to build an ADU.

Type of ADU Permit Required

There are restrictions and guidelines, but ADUs are by right in Orleans and are approved by the building commissioner.

ADU Rules

• The ADU cannot be greater than 800 square feet.

• Additions cannot increase lot coverage by more than two percent of the lot area.

• The lot must be at least 30,000 square feet of contiguous buildable upland.

• One of the two units must be owner occupied year round.

• The rental term must be at least 90 days.
  
  

  Likely changes after vote in May:

1. The accessory dwelling shall contain no more 1,200 square feet of floor area. 

2. The Board of Health must have documented to the Building Commissioner that sewage disposal will be satisfactorily provided for in accordance with the provisions of Title 5 and local Board of Health regulations, including provisions for an appropriate reserve area on the site. 

3. There are no limitations on lot sizes. 

4. The dwellings if leased shall be for periods of not less than ninety (90) days.

Resources:

https://www.capecodcommission.org/resource-library/file/?url=/dept/commission/team/Website_Resources/housing/ADU_Table_Nov2021.pdf 

https://ecode360.com/14200675 

Harwich, MA

Harwich, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 10/10 (10 is most accepting)

Last Updated: 6.18.2024

Image source: Winstead Inn

What You Need To Know

In Harwich, ADUs are referred to as Accessory Apartments.  These structures can be within, attached, or detached from the primary dwelling. 

Type of ADU Permit Required

ADUs or ADUs require a special permit.

ADU Rules

• Only one ADU is permitted per primary dwelling.

• The ADU and primary dwelling must have the same owner.

• Either the primary dwelling or the ADU may be rented, but only one unit can be rented at a time.  

• The rental period is limited to at least six consecutive months.

• There is a limit of 1,000 square feet of gross floor area for ADUs.

• The ADU may not have greater than two bedrooms

• There must be one parking space available for the ADU.

• The ADU must be designed in such a way that the property retains the characteristics of a single family home.

• All applicable zoning ordinances, setbacks, and sewer/septic regulations must be met.

Resources:

https://ecode360.com/44158044?highlight=accessory,accessory%20apartment&searchId=27717518857194543#12263178

Eastham, MA

Eastham, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating:
10/10 (10 is most accepting)

What you need to know 

Eastham loves ADUs and thinks they can help them ease their housing crisis. As with many towns in the Cape they allow all kinds of ADUs by right!

Type of permit is required?

ADUs are only allowed in the following districts:

By Right:

District A (Residential), E (Residential/limited commercial), G (Water Resource Protection), Core Commercial, Transition Commercial, Office Residential, Limited Commercial

By Special Permit:

District F (seashore)

Not Allowed:

District B (Marina), H (Wellhead Protection), and Trade Park

ADU rules in Eastham:

• Only one ADU is permitted on a single family lot.

• The unit must be a fully separate living area with its own kitchen, bathroom and egress.

• The ADU shall be clearly subordinate to the primary home.

• An ADU shall be designed so that the property continues to look like a single family lot and the privacy of abutting properties is maintained.

• The lot does not require a minimum acreage of buildable upland.

• The Accessory Dwelling Unit (ADU) shall contain no more than two bedrooms.

• The maximum size for an ADU is 1200 square feet or fifty percent of the site coverage of the principal dwelling, whichever is smaller. However, a Special Permit for an Accessory Dwelling Unit exceeding fifty percent site coverage rule can be issued.

• At least one 1 off-street parking space is required for each Accessory Dwelling Unit (ADU).

• The ADU and primary residence cannot be sold separately or divided into separate entities.

• Either the primary dwelling or the ADU must be occupied on a year-round basis. Short term rentals cannot occur in both units.

See the full text here: Zoning Ordinance Section VII C. Accessory Dwelling Units

Brewster, MA

Brewster, MA Accessory Dwelling Unit (ADU) Rules

As of 12.08/2025

What you need to know:

Brewster, like all of Massachusetts since the passage of the 2024 Affordable Homes Act, allows ADUs by right. Each town has slightly different rules surrounding ADUs, but they all must adhere to the framework outlined by the state. The rules for Brewster are outlined below. 

Type of ADU permit required:

ADUs in Brewster do not require special permits, and can be built using a traditional building permit. Residents are allowed to build one ADU per lot.

ADU Rules

• An ADU can be a maximum of 1,000 square feet.

• ADUs can be attached, detached, or built within the main house.

• Properties within ½ mile of a transit station do not require additional parking. Properties outside of that area require one additional off-street parking spot. 

• ADUs must have a separate entrance from the main house. 

• Attached ADUs can share an entry hall with the main house, but need a separate entry within the entry hall. 

• Short-term rentals are not allowed. The minimum rental period for an ADU in Brewster is ten months.

• The ADU must have a similar architectural style to the main house.

• The main house and the ADU must be owned by the same person(s).

Resources:

https://www.brewster-ma.gov/sites/g/files/vyhlif16031/f/uploads/100925_proposed_zoning_amendments.pdf

Wilbraham, MA

Wilbraham, MA Accessory Dwelling Units (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

Wilbraham does not allow detached accessory dwelling units (ADUs). Granny flats must be constructed within existing space or as an addition.

See the full text here: Zoning Ordinance Section 4.1 Accessory Apartments

Whately, MA

Whately, MA Accessory Dwelling Units (ADU) Rules

City Acceptance Rating: 5/10

What you need to know: 

Whately does not explicitly allow detached accessory dwelling units (ADUs).

HOWEVER, Backyard ADUs did receive approval to build one. We believe backyard tiny homes will be approved using the strategy we developed.

Call us for more info!

See the full text here: Zoning Ordinance Page 100, Section Accessory Apartments

Warwick, MA

Warwick, MA Accessory Dwelling Units (ADU) Rules

Updated: 11/17/2025 - Rules still being finalized

What you need to know:

Warwick, like all of Massachusetts since the passage of the 2024 Affordable Homes Act, allows ADUs by right. Each town has slightly different rules surrounding ADUs, but they all must adhere to the framework outlined by the state. The rules for Warwick are outlined below. 

Type of Permit Required:

ADUs in Warwick do not require special permits, and can be built using a traditional building permit. Residents are allowed to build one ADU per lot. 

ADU rules in Warwick:

• An ADU can be up to 900 square feet in Warwick. 

• ADUs may be attached, detached, or built within the main house.

• Short-term rentals are allowed in either the main house or the ADU, but not both simultaneously.

• Properties with an ADU may require additional off-street parking (driveway or garage).

Resources:

https://warwickma.org/wp-content/uploads/2024/12/2024-12-09-STM-Minutes-Complete.pdf

https://warwickma.org/town-clerk/2024-12-09-special-town-meeting-minutes/?highlight=%5C%22accessory%20dwelling%20unit%5C%22

Sunderland, MA

Sunderland, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

Sunderland does not have a section in its bylaw covering accessory dwelling units (ADUs).

However, the town does allow two-family homes in all zoning districts except C-2. If your property has enough space you may be able to add backyard tiny home as a formal 2nd unit.

See the full text here: Zoning Ordinance

South Hadley, MA

South Hadley, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

South Hadley does not have a bylaw for detached accessory dwelling units (ADUs). However, they do provide a path to convert single-family homes into duplexes following the rules in the town’s zoning ordinance.

In order to convert a property, owners must get written permission from 3 of their neighbors and their property must meet meet minimum dimensional requirements.

The zoning bylaw does not specifically state whether a detached structure (backyard home) could act as the second unit.

If you are interested in building in South Hadley and would like more concrete information, contact our team. The rules in South Hadley will be specific to your property and situation and we will need to confer with the building department.

See the full text here: Zoning Ordinance

Southampton, MA

Southampton, MA Accessory Dwelling Units (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

Southampton does not allow detached accessory dwelling units (ADUs). Granny flats must be constructed within existing space or as an addition.

See the full text here: Zoning Ordinance Section XI-K Accessory Apartments

Shutesbury, MA

Shutesbury, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 7/10 (10 is most accepting)

What you need to know:

Shutesbury revised its rules for Accessory Dwelling Units in 2008 to make it easier for homeowners to add an additional dwelling unit to their properties. The city sees ADUs as a great to way help increase density and create high quality housing without sacrificing the character of the town. Since the bylaw was approved, there have been many ADUs added to homes including at least one backyard home (detached ADU)!

Type of Permit Required:

Shutesbury allows both attached and detached ADUs by right with a site plan review by the Zoning Board of Appeals.

ADU rules in Shutebury:

• The property must have slightly more than 1 acre (45,000 SF, 1.03 acres).

• The primary home and proposed ADU must follow the district’s setback requirements.

• One of the two dwelling units must be owner occupied.

• An ADU can only be added to a single family property.

• No additional curb cuts can be created. Access to the ADU must be provided from an existing driveway or access road to the property.

See the full text here: Zoning Ordinance, Section: 4.4-2 Accessory Apartments

Plainfield, MA

Plainfield, MA Accessory Dwelling Units (ADU) Rules

City Acceptance Rating: 9/10 (10 is most accepting)

What you need to know: 

Plainfield loves ADUs and has a favorable permitting process. However, it is important to note that the town’s rules are very clear that the design and site plan must conform with the single family and rural characteristics of the town.

Plainfield also provides guidelines to convert a single family property to a multi-family property. If homeowners use this approach to add an additional apartment getting financing will be easier and they will maximize their home’s value. Multi-family conversions can only use existing space in the single family home (no additions or construction).

Type of Permit Required:

Plainfield allows both attached and detached accessory dwelling units (ADUs) to be built by right.

If a lot is nonconforming, an ADU requires a special permit.

ADU rules in Plainfield:

• An ADU can be added to either a single or two-family dwelling.

• It must be a fully separate living space including its own kitchen, bath, and egress.

• Only one Accessory Apartment can be added to a residential lot.

• The lot in question must conform to its zoning district’s rules (e.g size and street frontage).

• The ADU and site plan must maintain the residential and rural character of the neighborhood. Exterior modification, including new detached structures must match the existing architectural elements of the home.

• New entrances shall be located facing the side or front yard of the lot.

• Adding an ADU to an original building or a backyard ADU is permissible as long as it is subordinate to the dwelling.

• ADUs can not be larger than one third (33%) of the existing residential living space or nine hundred (900) square feet, whichever is less.

• Off-street parking spaces must conform to the schedule in Section 5.3.

• A sanitarian or professional engineer, registered in the Commonwealth of Massachusetts, must certify that the sewage disposal system can accommodate the additional apartment.

Read the full bylaw here: Zoning Ordinance, Section 8.2 Accessory Apartments and Multi-family Conversions

Pelham, MA

Pelham, MA Accessory Dwelling Units (ADU) Rules

City Acceptance Rating: 5/10 (10 is most accepting)

What you need to know:

Pelham’s ADU rules differ per zoning district, so it is important to know which district your property is located in.

Type of permit required:

Detached ADUs are only allowed by Special Permit in its Village Center Districts.

Conversion of existing space or additions are only allowed by right in its Village Center Districts.

See the Village Center Zoning Districts

ADU rules in Pelham:

• Act as a fully separate living unit with a kitchen, bathroom, and its own means of egress.

• Only one accessory apartment is allowed per lot.

• No more than three persons shall occupy the accessory apartment.

• One of the two units must be owner occupied. When the owner(s) is not living on the property the ADU must remain vacant.

• The ADU must be designed to match the character of the existing house and neighborhood. New entrances shall be located on the side or rear of the building.

• The ADU shall be clearly subordinate to the primary dwelling.

• The ADU cannot have more than two bedrooms and the maximum living area is 800 square feet or 1/3 of existing living space, whichever is less.

• The lot must have at least three, permanent off-street parking spaces. These parking spaces shall be screened from road ways and adjacent or abutting properties with dense, hardy, evergreen plantings, earthen berms, walls or tight fence, complemented by evergreen plantings or other decorative elements.

• The well and existing sewage disposal system must be reviewed by the board of health before a special construction permit is issued.

• The Zoning Board of Appeals reserves the right to grant variance from these rules to encourage the development of housing units for disabled and handicapped individuals and persons with limited mobility.

See the full text here: Zoning Ordinance Section 5, 125-9.1 Accessory Apartments

Palmer, MA

Palmer, MA Accessory Dwelling Units (ADU) Rules

City Acceptance Rating:

5/10 (10 is most accepting)

What you need to know: 

Palmer allows both attached and detached accessory dwelling units (ADUs) to be built by special permit. However, it is important to note that the town’s rules are very clear that the design and site plan must conform with the single family and rural characteristics of the town.

Type of Permit Required:

• Both attached and detached ADUs require a special permit.

• ADUs used as rentals to non family members are not permitted in the Rural Residential District.

ADU rules in Palmer:

Requirements for all accessory dwelling units

• If a home is being used as an ADU and as space to conduct business, the ADU must be occupied by family. The bylaw refers to this as “Home Occupation.”

• Only one entrance door can be added to the new unit that faces the street.

• Parking:

  • In the Village Center District, the zoning board of appeals may waive parking requirements if there is adequate public parking near the proposed unit.

  • One additional space is required if an ADU is being included in the construction of a new home.

• The ADU living area may be no more than thirty-three percent (33%) of the living area of the house or 800SF whichever is less.

Rules for Detached & Additions

• The exterior finish material must be the same or visually match that of the existing home.

• The roof pitch must match that the existing home.

• Trim must match that the existing home.

• Windows must match that the existing home in proportion and orientation.

• Eaves must project from the building walls the same distance as the eaves on the existing home.

Read the full bylaw here: Zoning Ordinance, Section 171-89 Accessory Dwelling Units

Montague, MA

Montague, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 8/10 (10 is most accepting)

Evaluate your property:

What you need to know:

Montague has very favorable rules related to backyard homes (ADUs). There are limited restrictions and their zoning bylaw overall does not place excessive regulations on what can be built on a someone’s land. Setback requirements are also some of the most accommodating in Western Mass. However, homeowners still need to apply for a special permit to build a detached ADU so it will be important to plan a project that considers neighbors and the public if your ADU will be visible from the street.

Type of Permit Required:

Living Space Conversion:

Conversion of space within an existing home can be done with only a building permit.

Additions and Detached:

Both new additions, conversion of existing detached structures and newly constructed detached structures require a Special Permit.

ADU Rules in Montague:

• Only one Accessory Apartment may be created on a single-family lot.

• Utilities, water & sewer must be integrated with the single-family dwelling.

• The owner must occupy either the ADU of primary home.

• The ADU must maintain the single-family character of the home

• The ADU’s design must match the character of the home

• New entrances shall be located on the side or rear of the building.

• New stairways to provide access or egress to the ADU shall be enclosed, screened, or located so they are not visible to the public.

• A ADU cannot be larger that 900 SF

• A minimum of two (2) off street parking space must be provided and the entire lot can not have more than 4.

• Minimum lot size requirements are waved in districts AF-1, RS-2 and RB

• The Building Inspector or the Zoning Board of Appeals may allow reasonable deviation from the stated conditions to accommodate features that facilitate access and mobility for disabled persons

See Dimensional Requirements (extracted12/14/2019)

See the full Zoning Ordinance here: Zoning Ordinance Section 8.5.2 Accessory Apartments

Monson, MA

Monson, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

Monson does not allow detached accessory dwelling units (ADUs). Granny flats must be constructed within existing space or as an addition.

See the full text here: Zoning Ordinance SECTION XXVI Accessory Apartments

Leverett, MA

Leverett, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

Leverett does not allow detached accessory dwelling units (ADUs). The town allows attached accessory dwelling units under extremely strict circumstances. The town also requires the special permit to be renewed every 2 years. We do not recommend building an ADU of any kind in Leverett.

See the full text here: Zoning Ordinance

Ludlow, MA

Ludlow, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: N/A

What you need to know: 

Ludlow does not allow detached accessory dwelling units (ADUs). Granny flats must be constructed within existing space or as an addition.

The accessory apartment must be occupied by a family member.

See the full text here: Zoning Ordinance Section 6.6 Accessory Apartments