Accessory Dwelling Units (ADUs) in Milton: Frequently Asked Questions

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Accessory Dwelling Units (ADUs) in Milton: Frequently Asked Questions

Contributed by Rachel Pozzar, Town Meeting Member, Precinct 8.

Q: Why do we need accessory dwelling units (ADUs)?

A: The population is aging, and many seniors are finding it difficult to afford to age in place. At the same time, recent college graduates cannot afford to live independently in their hometown. The median sale price of a single-family home in Milton is $905,000 (source:

ADUs provide additional housing options without straining infrastructure or changing the appearance of a neighborhood.

The following information underscores the need for Milton to diversify its housing stock (source: Town of Milton 2020 Housing Production Plan):

  • The proportion of Milton residents 65 years of age or older is estimated to increase from 15.4% in 2010 to a range of 25% to 26% by 2030, representing a gain of between about 3,000 and 4,000 residents. This is very high in comparison to the total projected population growth of about 3% to 6%.
  • Milton’s housing units are getting larger, from a median of 6.9 rooms in 2011 to 7.1 by 2017. This is likely reflective of some teardown activity, with larger more expensive homes replacing more modest and affordable ones.
  • Housing vacancy rates are about zero for both ownership and rentals, indicating extremely tight market conditions that drive up housing prices.

Q: Won’t allowing ADUs lead to the appearance of more multi-families being built throughout the town?

A: A principal requirement of the ADU bylaw is that any home or lot containing an ADU must maintain the appearance of a single-family dwelling. This is accomplished in several ways:

  • Any ADU allowed “by right” is required to be contained within an existing single-family dwelling with no modifications to the home’s exterior.
  • Any construction that involves changing the exterior of a single-family dwelling or creating/modifying an accessory building would require a special permit. The special permit would not be approved if the home did not maintain the appearance of a single-family dwelling. Neighbors and other stakeholders would have the right to attend the special permit hearing to review the building plans and voice any concerns they may have.
  • The zoning regulations that apply to each residential district will apply to ADUs as well. For example, the current bylaws state “no building of accessory use shall be erected or maintained within 10 feet of a rear lot line in a Residence AA or A district, or within 8 feet of a rear lot line in a Residence B or a Residence C district, or within 15 feet of a rear lot line in a Residence D district.” ADUs are not exempt from these regulations.

Q: Are “by right” ADUs free from oversight or regulation?

A: No. “By right” means a homeowner does not need to obtain a special permit to create an ADU that (a) is completely contained within their existing home, and (b) does not involve any changes to the home’s exterior.

ADUs that are constructed “by right” still require a building permit and certificate of occupancy. They are also subject to the existing zoning bylaws that govern residential districts.

Q: Does the proposed “cap” of ten units per year apply to all ADUs, or only those issued by special permit?

A: All ADUs will require a building permit and certificate of occupancy, regardless of whether they are created “by right” or by special permit. Since the 10-unit cap applies to building permits (not special permits), the ten-unit cap applies to all ADUs, including those created “by right.”

Q: Are there plans to eliminate the ten-unit cap?

A: Any removal of the ten-unit cap would have to be approved by Town Meeting. No individual or committee could remove the cap without a revised bylaw coming before Town Meeting for a vote.

Q: I heard ADUs will count against our subsidized housing inventory. Won’t this exacerbate our affordable housing shortage?

A: It’s true that ADUs will count against our subsidized housing inventory. However, temporary apartments– which are allowed in our current bylaws without an annual cap– also count against our subsidized housing inventory.

In any case, it’s important to remember that the need for affordable housing is not limited to the need for subsidized housing. A healthy community offers a variety of housing options to its residents, and currently, our town lacks options for people who can’t or don’t need to invest in a single-family home.

Q: Why don’t we just require ADUs to be affordable?

A: There are specific requirements for a unit to be included on the town’s subsidized housing inventory. According to the state, the unit must be subsidized by an eligible state or federal program; subject to a long-term use restriction limiting occupancy to income-eligible households for a specified period of time (at least thirty years or longer for newly created affordable units); and subject to an Affirmative Fair Housing Marketing Plan (source: State of MA). Homeowners would need to relinquish substantial control over the ADU for it to be included on the subsidized housing inventory.

Q: Why don’t we just restrict ADU residents to family members and domestic workers?

A: The family requirement restricts the homeowner’s right to decide for themselves who they will welcome to live on their property. Many people have close relationships with extended family members and friends who do not meet the definition of “family” under the current bylaw. Restricting eligibility to homeowners’ immediate family members may also have unintended consequences. For example, this type of restriction could limit racial and socioeconomic diversity in town.

Q: What impact will ADUs have on schools, traffic, and infrastructure?

A: Given their small size (no more than 900 square feet), ADUs are more likely to appeal to elders and young adults than to families with children. Towns that have implemented ADUs have not reported any discernible impact on school enrollment or traffic patterns (source: survey conducted by Needham, MA). Since ADUs are integrated into an existing lot, they do not require new infrastructure.

Q: Will homeowners be allowed to run an AirBnB or other short-term rental out of their ADU?

A: No. Short-term rentals are not allowed. Lease periods must be for six months or more, and the homeowner must occupy either the main house or the ADU.

Q: What happens when the home is sold? Can an ADU be sold as a separate unit?

A: The ADU must be sold as part of the primary dwelling. It cannot be sold as a separate unit.

Q: Where can I find more information?

A. The State of Massachusetts has published an overview of ADUs and case studies of towns that have existing provisions for ADUs, available here:

The AARP has provided a helpful information sheet on the benefits of ADUs to seniors, available here:

There is also a 2018 report on the status of ADUs in Massachusetts, available here:

See also:

All about Accessory Dwelling Units (ADUs) in Milton


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