Local Zoning & Regulations
What should a city/town do if its zoning is not consistent with the ADU Law?
As of February 2, 2025, any zoning provisions that are inconsistent with the ADU Law and ADU Regulations are unenforceable. A Protected Use ADU, as defined in the ADU Regulations, cannot be subjected to local regulations that are disallowed by state law. Therefore, local permitting decisions should not take into account any local zoning rules that conflict with the ADU Law or ADU Regulations in general or when applied to a particular Protected Use ADU permit application.
Is there a requirement for EOHLC to review and approve ADU zoning?
No, the statute does not require EOHLC to review or approve ADU zoning. Whenever a town amends its zoning or other by-laws, the Office of the Attorney General is required to review the changes and approve them or disapprove them if they are inconsistent with state law, including the ADU Law. The Attorney General’s Office does not review amendments to zoning ordinances of cities. For more information on the Attorney General's Office review of by-law changes, you can visit the website of the Office's Municipal Law Unit at Municipal Law Review | Mass.gov.
When a city/town is amending zoning to add the revised definition and process to allow ADUs as of right in single-family zoning districts, does it qualify for a simple majority to approve zoning at our legislative body or 2/3 super majority?
The Zoning Act, (MGL c40A) requires a simple majority vote to amend zoning to allow for ADUs (as defined in the Zoning Act) as of right. If a city/town wishes to establish rules that are more permissible than those allowed by the law and statute there may be instances where the vote would have to be by super-majority (ex. Allow Protected Use ADUs larger than 900 square feet as of right), or they may wish to cast two votes, one on the minimum standards and one of the expanded standards. Please consult with your town counsel or city/town solicitor for their legal advice. You can find Guidance on voting thresholds for zoning here: Voting Threshold Guidance | Mass.gov.
Can a city/town prohibit a Protected Use ADU from being permitted in property that has more than one unit such as a duplex, triple decker, or other multi-family home?
No. A municipality cannot limit Protected Use ADUs to lots with only single-family homes on them. The Attorney General’s Office has recently issued a decision that relates to this question, and we recommend cities and towns looking for answers to this question to carefully review this decision: East Bridgewater Accessory Dwelling Unit AGO Decision - April 14, 2025.
Can a city/town choose to permit Protected Use ADUs by right in some zoning districts but not other business or non-residential only districts that permit single-family homes?
No. Protected Use ADUs are allowed by right in all zoning districts in a city/town that permit single-family homes to be built by right or special permit, subject to reasonable regulations.
Can a city/town restrict the size of a Protected Use ADU to less than 900sqft by zoning or other local by-law?
A city/town cannot restrict the size of a Protected Use ADU below 900sqft but may allow for larger Protected Use ADUs.
Can a city/town set its own rules regarding Short-Term Rentals?
Yes. Adding Short-term Rental restrictions for Protected Use ADUs is a local municipal choice. Carefully consider the community context and if allowing Short-Term Rentals for Protected Use ADUs meets local goals and priorities. The ADU Law provides that municipalities may restrict or prohibit the use of a Protected Use ADU as a Short-Term Rental, as defined in M.G.L. c. 64G, §1 (Room Occupancy Excise). Prior to the ADU provisions in the Zoning Act, it authorized municipalities to restrict or prohibit short-term rentals except there was no definition for the term “short-term rental.” The ADU provisions citation to the Room Occupancy Excise means that a Short-term Rental is the rental of a Protected Use ADU that is subject to the Room Occupancy Excise, which applies only to stays of not more than 31 consecutive calendar days. The Room Occupancy Excise provides other key exemptions such as (i) lodging accommodations provided to seasonal employees by employers and (ii) tenancies at will or month-to-month leases, among other exemptions provided under M.G.L. c. 64G, § 2.
Can a city/town restrict who lives in a Protected Use ADU such as prohibiting college students?
No. The ADU law and regulations do not allow a municipality to regulate who can live in a Protected Use ADU.
Can a city/town require additional septic capacity or new septic systems to build a Protected Use ADU?
Only if required by state law. The ADU regulations prohibit local rules to be established that are more restrictive than state laws and rules, and so septic requirements that are greater than required by law cannot be enforced for ADUs by a zoning ordinance or by-law. Therefore, during the permitting process, Title 5 should be adhered to and there are instances where a city/town may be able to require upgrades, additions, or entirely new septic systems be built to meet the new capacity with a Protected Use ADU being built. Further guidance has been made available by Executive Office of Energy and Environmental Affairs and can be found both on www.mass.gov/adu and at MassDEP’s Guidance on Title 5 (310 CMR 15.000) Compliance for Accessory Dwelling Units.
Can a city/town establish rules that include definitions that are more permissive than the ADU law and regulations that allow for bigger Protected Use ADUs or other greater flexibilities?
Yes. The ADU regulations clearly state that a city/town can be more permissive than the rules established by the ADU law and regulations. Local rules may be more permissive on rules such as but not limited to: 1) maximum size, 2) greater or no percentage of Gross Floor Area, 3) reduced parking minimums for locations not considered within the law, 4) allowing Protected Use ADUs in properties that are not located within an eligible zoning district, 5) any and all of the standards that cities/towns can regulate where the local rules would be more permissive than the state law or regulations allow.
Can a city/town require two entrances for a Protected Use ADU to be permitted by zoning or local by-law?
A city or town cannot impose zoning rules for egress beyond what is required by state health and safety laws, including building codes. There may be instances where 1 entrance and 1 window will suffice to meet building code for egress, and other instances where building or safety codes require more than one egress, this should not be a zoning requirement for all Protected Use ADUs but addressed on a case-by-case basis by the building permit issuing authority.
Does the rule prohibiting parking minimums near "bus stations" include all flag stops or the entirety of a flag-stop bus route?
To establish minimum parking requirements for a Protected Use ADU, a "bus station" is a regular and specific location for pick-up and drop-off. Flag stops in between regular and specific pick-up/drop-off spots or flag stops along routes that lack regular and specific pick-up/drop-off spots are not considered "bus stations" for purposes of calculating parking requirements.
Permitting & Development Process
Can EOHLC answer questions from property owners about whether they can build a Protected Use ADU on their property?
EOHLC is not able to answer property specific questions about whether a Protected Use ADU is feasible to be built on a specific property. Please consult with your city or town to better understand your local rules, review the ADU regulations, and speak to a trusted legal, real estate, or building adviser to understand what options might be available to you.
How can a property owner get a permit to build a Protected Use ADU on a property they own?
The law permitting Protected Use ADUs as of right took effect February 2, 2025. As local zoning and procedures for review will vary from municipality to municipality, contact your municipality’s building department. They can share the status of local zoning rules, processes, and building standards that are specific to your city or town and to your property. As they work to implement this new law, please bear in mind that your municipality may not yet have all the answers as they work to implement this new law.
What should a property owner do if their permit to build a Protected Use ADU was denied, but their credible advisers are informing them it should have been granted?
EOHLC cannot answer questions on the specific circumstance surrounding a permit denial as there may be very specific, valid, or invalid reasons for a permit to be denied that we cannot determine. There are local appeal processes established by cities/towns. We encourage you to speak to a trusted legal, real estate, or building adviser and your city/town to discover what options might be available to you.
What should a property owner do if they think that a municipality improperly denied a Protected Use ADU permit? Are there alternatives to bringing a challenge in Land Court?
EOHLC cannot provide legal advice to property owners and if you were denied a permit for your Protected Use ADU you should contact an attorney. There may be avenues for appeal under MGL c. 40A.
Can a Protected Use ADU be turned into a condo and sold separately from the Principal Dwelling?
The ADU law and regulations do not directly regulate condominium conversions and towns have some authority to regulate condominium conversions, but whether a particular dwelling unit can be converted into a condominium under state and local law depends on the context. We therefore recommend that cities/towns speak with their legal counsel and that property owners speak to a trusted legal, real estate, or building adviser and your city/town to discover what options might be available to you.
If a principal dwelling was not built by-right, or through the underlying zoning, but through a zoning overlay district, but the lot is in a district that allows single-family by-right or special permit, should a Protected Use ADU be permitted by-right?
Yes. If a lot and principal dwelling are located within an underlying or overlay zoning district that allows single-family homes by right or special permit, that lot / principal dwelling is eligible to receive a permit for a Protected Use ADU regardless of the permitting mechanism that was used to permit the principal dwelling to be built.
Does the ADU Law supersede or require the permitting of Protected Use ADUs on all lots regardless of other state or federal laws that establish what can be built on a specific lot?
No. The statement of purpose in the ADU regulations says that “Nothing in [these regulations] is intended to supersede state health and safety laws and regulations, such as, but not limited to the Building Code, Fire Code, M.G.L. c. 111, § 189A: Massachusetts Lead Law, or any federal laws.” The intention of this statement is to ensure that any other applicable state or federal laws are followed.
Can Protected Use ADUs be detached from the primary dwelling in a single-family zoning district?
Yes. Detached Protected Use ADUs must be permitted without requiring a special permit or other discretionary zoning approval as long as they meet the definition in the Zoning Act. Cities and towns may establish reasonable regulations that are applicable to detached Protected Use ADUs.
Does the fact that a Protected Use ADU is by-right mean property owners can do anything to build a Protected Use ADU in their property?
No. All construction of Protected Use ADUs need to comply with local rules and codes and need a building permit. A Protected Use ADU must also be built in a legally permitted structure. For property owners interested in building a Protected Use ADU as a DIY project, we encourage you to speak to a trusted legal, real estate, or building adviser and your city/town to discover what options might be available to you.
Other Impacts & Related Policies
Where can property owners find information about financial resources such as loans and financing to build a Protected Use ADU?
Talk to trusted advisors and experts such as local banks or other financial institutions, and/or a building contractor. EOHLC will work with partner agencies, programs, and banking industry professionals to provide an overview of various ways in which property owners can finance the construction of Protected Use ADUs.
Will Protected Use ADUs count as units in the 2030 U.S. Census Year-Round Housing Unit count?
EOHLC anticipates that Protected Use ADUs that are built between now and the 2030 census, given an address, and receive a Census form, will likely count as year-round-housing after the 2030 census.
Is a Protected Use ADU eligible to count as a unit in the Subsidized Housing Inventory (SHI)?
A Protected Use ADU may count towards the SHI if it meets all of the SHI eligibility requirements. While a city/town cannot require affordability, they can encourage it, and there may be situations where a property owner may want to take the steps to restrict their Protected Use ADU to be affordable, and if such restrictions and other SHI eligibility requirements are met, the Protected Use ADU may count on the SHI. This is not a simple process, and cities and towns should speak with their municipal legal counsel to understand SHI eligibility requirements.
The ADU law applies to 350 cities and towns, why is that not 351 since that is how many cities and towns there are in Massachusetts?
All cities and towns in Massachusetts, except for the City of Boston, are subject to the ADU law because Boston is not subject to the specific General Law (c40A) that the ADU law was written under. Boston residents can learn more about Boston’s ADU rules at Accessory Dwelling Units (ADUs) in Boston | Boston.gov.
Resources & Technical Assistance
Will there be training or technical assistance to cities/towns on how to be consistent with the new ADU law?
Yes. EOHLC has created webinars and will continue to provide additional webinars that are recorded and posted to www.mass.gov/adu. We will also provide office hours for municipalities, consultants, and planning and zoning experts to meet with our ADU team and have their questions answered as they prepare to make local zoning amendments related to ADU. Other resources may be available in the near future, including but not limited to meetings and webinars for building inspectors/permit issuing authorities, assessors, and others.
Will EOHLC develop a model ADU bylaw?
Yes, EOHLC, in partnership with the Metropolitan Area Planning Council (MAPC) and Massachusetts Housing Partnership (MHP) has created a model bylaw that will be consistent with the Zoning Act and the regulations. EOHLC has also created a checklist that will help cities and towns “audit” their own zoning to see what changes should be made for consistency with the new ADU law and regulations.
Are there grant funds available to municipalities to hire a consultant to help revise the zoning to meet the new rules?
Community Planning funding is available through the Community One Stop for Growth program. Learn more at www.mass.gov/onestop.