Accessory dwelling units: An intergenerational tool for housing challenges

Updated May 15th.

A new building bylaw — signed by top Massachusetts officials and recently approved by towns on the Island — allows a tool that could play a significant role in addressing the Island’s housing struggles: accessory dwelling units, or as they’re more commonly referred to, ADUs. 

From a small cottage apartment to a lofted space above an existing garage, or a walkout basement below, housing experts have touted these secondary dwellings as a key to increasing housing supply. 

After reporting by the Boston Globe found thousands of ADUs could be added to the housing stock on the Island, and through several interviews by The MVTimes with Islanders who have created versions of these secondary apartments over the past few decades, the new streamlined permitting process could help ADUs become a more affordable tool for locals hoping to age in place, for families to provide housing for their children, or for Island workers. 

The prior zoning laws have forced some to build a completely new house just so they could have an accessory apartment, while others have had to gain the support of their neighbors through petitions before getting town approval. 

With a waiting list sprawling over hundreds of retired Islanders for assisted-living apartments and an overall shortage of housing, the age-in-place model may be a better option for families looking to help their older members or house a caretaker on their property. Additional units could also lower costs Island-wide by increasing supply. 

According to housing planner Laura Silber, there’s a reason advocates for retired residents have been proponents of ADUs. 

“It’s notable that AARP [American Association of Retired Persons] has been one of the strongest advocates for ADUs by right nationwide — they are an important tool to create opportunities for multigenerational families, provide downsizing opportunities, and allow an alternative solution for overhoused seniors to stay in their homes by converting use of the existing space into a small separate unit,” Silber said in a statement. 

ADUs, referred to as protected-use ADUs in the new legislature, are secondary structures attached to or nearby a primary dwelling. After Massachusetts Gov. Maura Healey signed the Affordable Homes Act into law in August 2024, allowing ADUs by right for homeowners — which means they can be built without excess interference from municipalities — new possibilities are opening up for homeowners and housing groups alike. 

And at recent town meetings, Island community members amended the bylaw as they saw fit. In Chilmark, residents voted to lift restrictions and allow ADUs on any property to be up to 900 square feet, no matter the size of the primary dwelling, instead of the original bylaw, which stated an ADU could be half the size of the primary home, or 900 square feet — whichever was greater. And in all six towns, added language that prevents ADUs from being used as short-term rentals was added, ensuring that the additional units will provide much needed housing for year-round residents rather than further bolster the rental-fueled tourism industry.

While the new law makes it easier to build ADUs, Islanders have likely already seen the former iteration, a similar yet differently zoned building structure called accessory apartments. Many locals have lived in small shacks on someone’s property at one point or another, although many of the structures that already exist are unregulated and lack official permits, making them more difficult to rent out. According to interviews conducted by The Times, the ones that are legal reportedly took years and significant effort to have approved.

The Times documented four families who have been able to live on the Island thanks to accessory apartments, as an example of diverse housing types that already exist here. 

But the new ADUs — approved by the state legislature and at local town meetings — are different. Not only will they be easier to get approved, they are specifically zoned by the state to increase housing stock where it is lacking, and provide support for year-round residents and lower- to middle-income earners. 

In counties and towns where ADUs have been allowed by right, housing stock has gone up, prices have gone down, and there are more options available for renters. California is a common example of boosting housing inventory through ADUs. The state passed a combination of regional and local zoning laws in 2016 similar to the one outlined in the Affordable Homes Act, which triggered a statewide building boom and provided housing for thousands of residents. As of 2022, six years after the zoning ordinance, nearly one in five of every dwelling in the state of California is an ADU, according to a report from a California housing group. 

As the Affordable Homes Act in Massachusetts stated, “The new law on ADUs is an example of a small policy change that will make a big difference.”

Now on the Island, if homeowners want to build an ADU on their property, they can take their plans directly to their local building inspector, and be assured that if their unit has wastewater capacity, acceptable square footage, and abides by health codes, they can start building. 

And there is evidence and prior reporting to suggest the apartments could make a sizable dent in housing needs on the Island. 

The state Executive Office of Housing and Livable Communities recently estimated that 8,000 to 10,000 ADUs could be constructed in the next five years across Massachusetts, due to the streamlining of the new zoning process. And in 2023, a Boston Globe report by its Spotlight Team found that thousands of ADUs could be built on the Island. 

On the Island, the numbers of single-family parcels with a backyard large enough to build an ADU, according to the Spotlight team, are as follows: Oak Bluffs: 1,889; Edgartown: 2,579; Tisbury: 1,246; West Tisbury: 797; Chilmark: 295; Aquinnah: 109.

Island planners have long seen ADUs as a way to boost housing efforts. And the need has been documented. According to a 2024 housing needs assessment, conducted by the Martha’s Vineyard Commission, there’s a shortfall of at least 2,775 housing units on the Island, including 657 rental units and 2,118 owner units. In a recent interview with Ewell Hopkins, former planning board member in Oak Bluffs, he said ADUs are an effective tool to address housing needs. 

“I think [ADUs are] a good component,” he said. “It’s a good step in the right direction.”

But building an accessory unit of any kind takes a lot of the one thing that many locals struggling with housing are low on: Money. The cost of building any structure on the Island is substantial. 

“[ADUs being allowed] doesn’t take away the fact that building anything here is difficult. Difficult in the way of funding. It’s expensive,” Arielle Reid Faria, co-chair of the Coalition to Create the MV Housing Bank, said. “Any structure here is expensive now.”

However, the cost to build an ADU on an existing property is far lower than a home. In interviews with residents who have built accessory apartments, the costs are in the hundreds of thousands of dollars, rather than the median home sale on the Island, about $1.5 million. 

And according to Adam Petkus, the building inspector in Chilmark, at a recent town meeting, locals in that town who are finding it difficult to fund a home build on their property — or who need somewhere to stay while their larger home is being built — can build an ADU first, zoned as a primary dwelling, and then rezone after the fact for the larger structure. 

Silber said the use of ADUs going forward is more adaptable than the previous zoning for accessory apartments.

“The new by-right law in Massachusetts provides more flexibility for long-term use than the local Island bylaws used to, which reduces barriers to creation and provides homeowners an opportunity to adapt use of their ADU as their needs change,” she said. “Combined with the STR [short-term rental] prohibitions adopted by the M.V. towns on the units, this directs the units’ use toward year-round use or seasonal workforce housing solutions, rather than as vacation units.”

According to those working toward housing solutions, there’s no easy answer — just imperfect actions that equal promising long-term results. 

In response to housing concerns or interest in multigenerational styles of living, some local families on the Island, like the Cabots, Douglases, Dewings, and Dagostinos, have gotten creative. In order to live intergenerationally, they’ve built according to legal zoning of their time. 

But if their timeline for building additional units was moved up to now, the process for building an accessory unit would be more streamlined, and the structures themselves might look different. But each family expressed the same sentiment: The style of living that accessory units allow has improved their quality of life, and that of their family. 

When the Dagostino family was discussing their accessory apartment, they said their days changed for the better when Sheryl Dagostino’s retired parents moved in, and the generational differences in the house have ultimately been an improvement. 

“It’s been a good thing for all three generations,” she said, referring to herself and her husband, her son, and her parents all living under the same roof. “It’s integrated into our routine. And it all comes down to compromise.”

 

Stories from Inside

Four families speak of the convenience, and affordability, of living in a separate but connected space.

Editor’s note: Accessory dwelling units, called ADUs, are seen as a tool — thanks to a new state law — that could address housing shortages on the Island, especially for seniors who can age in place with their families. A version of the apartments has been allowed on the Island in the past, but had more difficult permitting requirements. The Times sat down with four families who have utilized this tool — some that have lived in them for decades — to understand what the experience of living intergenerationally is like.

The Douglas family

On a flower-lined back street in downtown Vineyard Haven, retired couple Kristen, 67, and Ian Douglas, 66, live in an environmentally conscious, net-zero home with their 34-year-old daughter, Joanna Douglas. Joanna is a farmer and owner of the local business Fork to Pork, and she lives in an accessory unit just a few feet away from her parents, on the same property. 

At 596 square feet, the accessory apartment is small yet functional, with just enough space for Joanna and her boyfriend. 

The Douglas house is sustainable in more ways than one. Their home, modularly built offsite and assembled in blocklike formations on their property, is completely aligned with their values. A modular style is a more environmentally friendly way to build, and uses less energy and waste. The Douglases also use solar energy to bring their property to their own standard of living. 

But according to Ian Douglas, a retired Episcopal bishop, their awareness of the housing crisis on the Island also influenced their idea to build an accessory apartment. 

“A big part of [the process] was to — if possible — help provide housing both for Joanna, and get it licensed as an official ADU [accessory dwelling unit] so that we could add housing stock to the Island for worker housing,” Ian Douglas said. 

If Joanna ever decided to move out, Ian Douglas said, they would want that unit filled by a tenant, and it was important to them to go through the process legally and without cutting any corners. 

Kristen and Ian Douglas hadn’t planned on building a completely new home when they moved to the Island in 2020, but when they read up about zoning regulations and building restrictions related to accessory units, they were faced with the reality that the units would be too difficult to permit, especially in Tisbury, largely due to wastewater limitations and the zoning of the time. They spent hours poring over zoning rules, and decided to create exactly what they were envisioning from the ground up — and to do that, they built a new home from scratch, with the accessory apartment included in their floor plans, which was subsequently simpler to permit. 

“We worked closely with the town’s bylaws and the inspector,” Ian Douglas said. “Instead of letting our desires dictate, we let the bylaws dictate. Then we tried to design within those confines … to make sure we were doing the right thing.”

Ian Douglas said their family ended up building an accessory unit that almost completely aligns with the new Massachusetts zoning bylaws for protected-use ADUs — a possible example for other Islanders who are looking to embark on a similar journey that will be much easier, thanks to new state and local zoning changes. 

And their ultimate goal is providing an essential housing unit to the Island’s workforce if their daughter ever decides to move away. 

“If [Joanna] chooses to live elsewhere, we would rent it to either a medical worker, or a teacher, or some other person who is a year-rounder and needs to live on the Island,” Douglas said. “We felt … that if we’re fortunate enough to build something for ourselves, then we should include worker housing.”

“And you know, we’re so [lucky] that Joanna’s living in it right now, our daughter. Whether that’s forever, who knows, but right now it’s perfect.”

The Dewing family

On the small Island of Chappaquiddick, Ernie Dewing and his mother, Shirley Dewing, live in two separate structures on the same parcel of land of just under three acres. 

Shirley Dewing, 88, resides in the main house — a 1,500-square-foot, gray-shingled, colonial-style home. Ernie, 65, lives in an accessory apartment–turned–recording studio. The two are connected by meals, daily check-ins, and quality time, and separated only by a few feet, with one shared wall. 

Ernie Dewing said it’s been a life-changing arrangement. No longer does he have to shuffle around the Island — searching in vain for housing, as he was for years, like many other Islanders — and his mother, who’s lived on-Island for more than two decades, has the peace of mind that she can comfortably age in place in the home she knows and loves. 

“I was just bouncing from place to place before I built my [accessory apartment],” Ernie Dewing said. 

The 660-square foot, add-on accessory apartment aligned not only with the mother and son’s living styles, but also their income. Both Ernie Dewing and his mother are retired and on fixed incomes, and building or buying another home on Chappaquiddick wasn’t in the cards for them, with real estate prices nearing $2 million on average. 

But in order to get the structure built, they needed to get creative. Zoning for an accessory apartment was a long process, and they needed special permitting for the structure they wanted. So Ernie and Shirley Dewing went to their community for help.

The pair gathered more than 30 signatures from neighbors, who all wrote in support of the proposed build, to submit to the Edgartown building inspector. Ernie Dewing said he believes the letters turned the tide in their favor. Otherwise, he said, the process to zone and approve a structure like the one he built would be much longer and more complex. 

Making the space a recording studio was a way for Ernie Dewing to do what he loved, where he loved doing it. In addition to a bed, kitchen, and bathroom, the small apartment has multiple electric pianos, a recording station, comfortable seating, and more than 10 guitars displayed on the walls — a functional art installation, musician edition.

And in terms of their intergenerational style of living, Dewing said his ability to care for his mother feels like a natural response to her care for him growing up. It’s been important for him to be close by, providing support, safety, and comfort. 

“It’s wonderful. He comes with dinner every night,” Shirley Dewing said. “I don’t think we would have been able to do this if it wasn’t for … the [accessory apartment].” 

The Cabot family

For some locals who have an intergenerational living accommodation, the additional apartment was already built into the West Tisbury home they purchased. That was the case for Nicole Cabot, who moved her parents into their basement to age in place on the Island. For her, it was a matter of remodeling instead of building. 

With many other locals citing struggles with permits, zoning, and approvals related to their accessory apartments, Cabot was able to bypass these factors and get right to usage. 

When she and her husband bought their home, their basement had a separate kitchen, bathroom, and bedroom already. Cabot fixed up the area, and made it into an at-home daycare first, providing much-needed childcare services to the local community. 

Then, as her parents got older and she moved on from daycare, she and her husband decided to alter the space again, into an 800-square-foot basement apartment for them. And she said the style of living makes sense for their needs.

“It’s great for my children to have grown up with their grandparents right at the house,” Cabot said. “I think it added to their childhood a lot.”

Cabot is an only child, and when her parents needed some extra support, she knew that accommodation was up to her to provide. Moving them to the Island was essential. But financially, buying another home was too costly, and elderly housing at Havenside had a years-long waiting list.

“I had to figure out how to get them to live close to me in an affordable way, and this seemed like the only option at the time,” she said. “It’s really important to us to have our own space.”

After her father’s passing last year, Cabot’s mother, Linda Vadász, still resides in the accessory apartment downstairs, and has for about 11 years.

Due to the success of the downstairs unit, Cabot said she’s now looking into building an accessory dwelling unit (ADU) on her property for her daughter to live in, with ADUs now allowed by right. 

“My heart breaks for all the people who can’t put down roots on the Island, you know, the whole next generation,” Cabot said. “I mean, how are they ever going to put a down payment on a house that’s almost $2 million? There’s just no opportunity.”

But with the new ADU zoning bylaw, Cabot said, she sees a hopeful future for locals who are housing-insecure. 

“I think that the ADU piece is going to make a dent in that,” she said. “I would hope that people would not build them and then use them as a [short-term] rental. I hope that people can actually figure out how to get our community to have the next generation feel like they can put down roots.”

The Dagostino family

Ron and Sheryl Dagostino’s home in West Tisbury is inviting and warm, without unnecessary clutter, but with plenty of character. Their space is curated down to each shelf, white-walled and bright, with colorful paintings and photographs lining the walls. 

But the creativity in their space doesn’t end with their decor. It’s exemplified by the structure itself. The family built an accessory apartment in order for Sheryl Dagostino’s parents to age in place with them. 

The process started in 2021. It took over a year to build, months to get approved, and even longer to plan, but by 2023, the grandparents were settled into their own space, which is attached to the main home, yet comfortably separate. 

Their apartment is a hallway, sitting room, and door away from their daughter and son-in-law. The space between is lined with windows, plants, and shoe racks on shelves along the walls, a door to the shared living room that usually swings open, and a few doors to the outside deck. According to the three generations who live in the home, the arrangement took a lot of work, but has turned out to be a blessing. 

“It doesn’t have to be huge to be livable and functional,” Sheryl Dagostino, a personal trainer, said as she pointed to all the ways the accessory apartment had to be thoughtfully designed in order to be fully functional, such as tucking an office space into a closet. 

Sheryl Dagostino’s parents were living in New York, but retirement during the COVID shutdown was taxing and isolating, and influenced their decision to move to the Island. 

They funded and helped design their accessory apartment, abiding by the zoning ordinance of the time that the square footage they were looking to build would be attached to the primary dwelling, lived in by family members, and up to code. While the cost was substantial, a few hundred thousand dollars later, they had a space of their own for much less than the local median home price of $1.55 million. 

The affordability of buying a home here was much less accessible for the retired couple, who are now on a fixed income, than building onto the existing structure. And Sheryl and Ron Dagostino said the process was worth it for the peace of mind they have knowing the next generation is so close by. It’s not just because of the safety that their housing situation automatically supplies them with, but also the influence of the grandparents’ wisdom on the youngest generation, Sheryl and Ron Dagostino’s son. 

Some of the grandparents’ furniture has made its way to Sheryl and Ron’s side of the home due to space restrictions. The things that have stayed have been important enough, and the furniture that has swapped over is simply moving to a different side of the house. Changed, but still theirs, much like their housing situation in general. 

“There’s compromises — not only in space, but in the objects you love that don’t move with you,” Barbara, Sheryl’s mother, said. 

“There’s something to be gained, but it takes work to get there,” Sheryl Dagostino added. “[But] it was an honor to have them move so close.”

Updated to reflect that all towns, not just Oak Bluffs, adopted language on the ADU bylaw preventing any future units from being used as short-term rentals.