Watertown has a decision to make about what kinds of accessory dwelling units the City will allow to exist. A discussion about ADUs (also known as in-law units or granny units) will be held on Monday, March 24, where residents can learn more about what they are and give input about what kinds they would like to see.
The State’s Affordable Homes Act, passed into law in 2024, requires cities and towns to allow certain kinds of ADUs, said Cliff Cook, a member of the Watertown Affordable Housing Trust, when he appeared on the Watertown Cable show “Inside Watertown.”
For the past few years, the subject of ADUs has been brought up by City Councilors and others in Watertown.
“They are a way of giving the property owner, the homeowner, some additional flexibility in how to use their property,” Cook said. “And they provide more housing units, which is something that Eastern Massachusetts is in desperate need of.”
ADUs are self-contained living units on a lot that has another, main living structure, Cook said. Typically they are rentals, but not always, and are often built for family members. They can be within the principal housing unit (such as a basement), attached to the building as an addition, or a free standing structure such as a garage.
They must have all the typical facilities found in a house, including its own kitchen, bathroom, and a sep entrance, Cook said, and ADUs have to follow all building and health code rules.
They are rented at market rate, Cook said, but because of the size and amenities, the rent is typically lower than other housing units.
With the law passed, Cook said Watertown still has a chance to tailor it to the City. The Affordable Housing Trust decided to organize the Community Dialogue on Monday with the help of Watertown Community Conversations.
“We are trying to get a sense of how ADUs could best fit into the community. There are certain ADUs we have to allow but after that there is a lot of discretion,” Cook said. “Do we want to push further into that discretion area? Do we want to pull back and just allow protected class ADUs? If we allow some discretionary ADUs, do we want them to be bigger? Have parking be required? Would there be different design standards for those — a different permitting process?”
The protected class ADUs, which are the ones that are required by state law, can be no bigger than half the size of the principal dwelling unit, or 900 sq. ft. — whichever is smaller, Cook said. They are allowed in any zoning district that allows single family homes by right, he said, adding that there are some other rules.
“For protected accessory dwelling units that are within a half mile of a bus stop, the City cannot require parking,” Cook said. “As it turns out, just because Watertown is a relatively small place, all the districts that allow single family dwellings are within a half mile of a bus stop. So, for protected ADUs there can never be a parking space required.”
The state law allows for them to be in owner occupied or renter occupied homes, and can be in single-family and two-family homes, Cook said.
The input from the ADU Community Dialogue will help the Affordable Housing Trust draft recommendations to send to the City Council, which will draft the ADU ordinance, Cook said. It will also be reviewed by the Planning Board and ultimately adopted by the City Council.
Cook provided some information about nearby communities that already allow ADUs. Newton, — which has 30,000 housing units compared to Watertown’s 17,000 — created 121 ADUs since 2017. Lexington, which has 12,000 housing units, has added 31 since 2016.
“I don’t think we are going to be seeing a land rush (to create ADUs,” Cook said. “There may be initially a little peak of people interested in doing this for a long time, but it is probably going to dwindle down to just a handful every year, over time.”
Affordable Housing Group Takes Stance on ADUs
The Housing for All Watertown group supports expanding the types of ADUs allowed in Watertown. A brief about ADUs recently sent to members of the group, says ADUs provide an opportunity for more homes, more affordable homes, and a more diverse and resilient housing pipeline. Those goals can be achieved if “we get the details right.”
“While the state has set minimum ADU standards, they have given cities and towns discretion to regulate the details, and these details are critical to ensuring ADUs are actually built,” Housing for All Watertown said in a statement. “To reap the benefits of ADU legalization, Watertown must make ADU construction as accessible as possible to homeowners by: helping homeowners understand options for financing ADU construction, simplifying and streamlining the permitting process, using dimensional standards that give the most flexibility in placing an ADU on their lot, and charging as few fees as possible.”
Housing for All Watertown said it is excited for the benefits that ADU expansion can provide including:
- More homes. Massachusetts ADU regulations are based on national best practices from California and Seattle. With similar production levels, Watertown can add 25 to 50 more homes a year, a 17-35 percent increase over the current housing production rate. Each ADU built is a home that prevents the displacement of a current resident, and creates space for new residents. The accessibility of ADU construction to homeowners also provides residents with flexible housing options, creating places for college students to return to, starter homes for couples to establish their families in, and accessible homes for older residents to retire to. The rent from ADUs can also help homeowners weather uncertain economic times while providing more affordable apartments to renters.
- More affordable homes. ADUs can be built at 12-50 percent of the cost of a multi-family unit and these cost savings are often passed on to tenants. Surveys across multiple states found that ADU rents are more affordable than the average unit, and many are affordable at 80 percent and 60 percent Area Median Income (AMI), without any deed-restrictions or incentives. There are also popular Affordable ADU programs that use bonus incentives to promote the creation of deed-restricted affordable ADUs, which Watertown could use as a model.
- A more diverse and resilient housing pipeline. Watertown currently adds housing through large, multi-family projects that are susceptible to commercial real estate market trends, as demonstrated by the recent lab boom and bust. ADUs complement multifamily projects. They are built by homeowners and are separate from commercial real estate, protecting Watertown’s housing pipeline against swings in the commercial real estate market.
Some of the recommendations of the brief is to allow pre-approved plans reduce the upfront costs of ADU construction, create a guide for homeowners interested in ADUs, simplify permitting for ADUs to be added to two-family townhouse-style condos, and allow ADUs in the Neighborhood Mixed Use zone (which was created during the Watertown Square Area Plan process).
Other opportunities would be to exempt ADUs from the floor area ratio (FAR) requirements, exempt them from triggering a sidewalk replacement, allow the internal ADUs to use the entire footprint of the building by-right, in the two-family zone allow ADUs to be the size of the principal residence as a way to preserve starter homes, and develop standardized fire code regulations for a detached ADU.
ADU Community Dialogue
The Community Dialogue on Monday, March 24 will be led by Watertown Community Conversations (WCC). After a short presentation, attendees will break up into groups for a discussion facilitated by members of WCC. At the end, everyone will gather for a large-group summary.
The March 24 ADU Community Dialog will be held at The Apartments at Coolidge School, 319 Arlington St., from 6 to 8:30 p.m.. Light food and beverages will be served at the beginning of the event.