AMHERST — In a town like Amherst, where numerous rental apartments are offered to local students, it has long been a legal right to allow granny flats with kitchens, bathrooms and bedrooms, as long as one of the two units on a property remains occupied by the owner.

With the Affordable Home Ownership Act recently signed by Governor Maura Healey to stimulate housing construction in Massachusetts, such accessory dwellings are now permitted in all municipalities in the state. And with language that states that “no municipality shall unreasonably restrict the creation or rental of accessory dwellings that are not for short-term rentals,” some of the regulations appear to be repealed, including the owner requirement in Amherst and other municipalities that prohibit freestanding or detached accessory dwellings.

Cities and towns across the state have 180 days, or until February, to bring their zoning plans and ordinances regulating granny flats or accessory dwellings into line.

Local attorney Michael Pill, who advises Amherst town officials, landlords and property managers on the change in the law, believes the new law may cause some discomfort.

“I believe this will end the long-standing debate in Amherst and other towns about increasing density in single-family home neighborhoods,” Pill wrote in a memo to officials.

Since every single-family home in a single-family residential neighborhood is legally entitled to an “ADU,” many restrictions fall by the wayside.

“I can already hear the cries of protest from the property owners of Amherst who have blocked special permits for ADUs in the past,” Pill said. “That era is over.”

While accessory dwellings are of limited interest in Amherst, Ira Bryck, who analyzes the town’s housing situation, recently wrote on the Amherst Indy website that the new rules show that state authorities do not understand the impact this would have on a college town.

“If it becomes popular now that there is no longer an owner-occupancy requirement, it will obviously be just another way to create overcrowded/overpriced student housing in Amherst neighborhoods,” Bryck wrote.

Oversight in Amherst is largely handled by the building commissioner. Senior planner Nate Malloy said that regulatory approval is only granted if the accessory dwelling is more than 1,000 square feet, in which case a special permit is issued.

Malloy told the Planning Board last week that the city charter may need some changes due to state legislation. “We require owner-occupancy, which is currently the only thing that violates the proposed changes that go into effect in February,” Malloy said.

However, the city can add designs and standards, architectural features and other criteria within reasonable limits, Malloy said.

This is essentially the way Northampton has handled them since 2021, when the city changed its ordinances to eliminate single-family-only zoning and no longer use the term “accessory dwelling unit.”

“We allow two-family homes in every neighborhood,” said Carolyn Misch, director of the Office of Planning & Sustainability.

Misch explained that second homes of any size are already permitted in Northampton’s residential areas as long as they meet minimum criteria regarding design, building distances, open spaces, heights and other dimensional criteria.

Before the change three years ago, however, Northampton had size restrictions of up to 84 square metres and a requirement for owner-occupancy. Every year a few additional apartments were built under these rules, Misch said.

It is still unclear what impact the state law will have, Misch said, but if more developers pursue such housing options as a result of the state loosening regulations, granny flats could be built in more of the city’s buildings.

“I would imagine there could be an increase in small second homes just because there are now builders that are focused on marketing these to people, and I would guess that the construction market could focus more on this niche to appeal to communities that never had this opportunity,” Misch said. “So the more builders that offer these types of projects, the more competitive the landscape could become and therefore more financially feasible for the customer/owner in Northampton.”

Municipalities that have enacted accessory dwelling unit regulations have often justified their actions by saying they want to provide people with the opportunity to move to a smaller apartment and remain in the same property so that they can age there rather than having to move elsewhere.

Like Northampton, many other towns have adjusted their statutes and ordinances over the years. For example, Deerfield amended its statute in 2023 to allow accessory dwellings to be occupied by any tenant, not just caregivers or people assisted by the owner of the primary residence. It also eliminated the requirement for a special permit from the Zoning Board of Appeals.

South Hadley Town Meeting members expressed concerns about increasing population density, noise pollution and privacy invasions in 2023 before voting to allow both attached and detached ADUs. Those who supported the ordinance called for more affordable and accessible housing options.

Most of these need to be amended and readjusted to clarify that an additional dwelling unit can be accommodated in residential areas, while possibly maintaining reasonable size requirements.

Smaller towns without a septic system or communities where most homes are not connected to the public sewer system probably won’t feel much of the change because the state’s housing law does not change the Sanitation Ordinance (Title 5), which limits the number of bedrooms in a home based on the size of the septic tank.

Pill pointed out that septic tanks must be designed for a specific number of bedrooms and most of them are then built for the actual number of bedrooms in the original house.

“Generally, no one wants to pay for an oversized septic tank built for extra bedrooms,” Pill said. “So an ADU requires either extending the existing septic tank or installing a new one if there is room on the property.”

Like Amherst, Hadley has an ongoing problem of existing single-family homes being converted for the rental market. Whether there will be a surge in additional housing units here is uncertain, as many residential lots are relatively small and Hadley’s zoning regulations require a building lot to have 10,000 square feet for each bedroom.

“We don’t have sewer everywhere, and if we add another bedroom, that changes the Title 5 requirements,” said William Dwyer, clerk of the Planning Board. “That will be difficult for a lot of properties in Hadley.”

Dwyer said Hadley has never denied a request for a special permit for a residential development, and the proposed changes would be in an administrative review process to assist the building commissioner. He expects the changes already drafted will likely impose reasonable limits, such as maintaining the setback and side setback requirements, requiring the dwelling to sit on a foundation, and requiring water and sewer connections to be connected to the main house. The ban on detached dwellings, which only allows use as accessory buildings adjacent to or within the main building, will no longer apply.

“In some ways I think it will have an impact, but I don’t think we’ll be inundated with detached apartments overall,” Dwyer said.

It is unlikely that the concerns would be comparable to those in 2015, when a Mount Holyoke College graduate sought a zoning change so she could continue living in her tiny home with a kitchen, bedroom, bathroom and living room in a 180-square-foot trailer on wheels.

During a discussion of proposed changes at Tuesday’s Planning Board meeting, Planning Board Chairman James Maksimoski said that while it would be easy to convert a garage into a granny flat, it would also be expensive due to building codes – an irony of the demands placed on cities and towns.

“One part of the state is pushing to make everything affordable, and the other part of the state wants all these changes that are driving up costs,” Maksimsoki said. “But we have no control over either, we just have to comply.”

Scott Merzbach can be reached at [email protected].