Susan Gittelman

Housing is in short supply in our region, particularly housing that serves the needs of the fastest growing demographics in our region: young professionals and seniors. Creating more housing units – apartments or condominiums, especially located near public transit – is what is needed.

Unfortunately, given limited available land near transit and the cost and difficulties to permit and build, this housing is rarely created at scale, particularly in Greater Boston.

Collectively, “accessory dwelling units,” as they are called, could make a significant dent in our housing deficit, most housing groups agree. Supporters of ADUs include many public officials, planners and the real estate industry.

ADUs, sometimes referred to as “granny flats,” can accommodate young or old, relatives or the unrelated, students or the working or the retired. These small units inside larger single-family homes already exist in some communities, both authorized and unauthorized. The zoning rules vary widely across the state, and that’s one of the reasons ADUs haven’t caught on faster.

U.S. Census figures show that household sizes have decreased significantly in recent decades. Single-family houses are the most prominent housing type in most communities, and most Baby Boomer homeowners have some empty rooms. Add to that the fact that older people with fixed incomes and rising costs may want to stay in their homes but find it financially difficult or too physically demanding. In these cases an ADU may be a valuable option with obvious benefits for both a homeowner and tenant.

Potential Abounds

Interestingly, according to a Pioneer Institute for Public Policy research study a few years ago of the 187 communities within 50 miles of Boston, 107, or well over half, allow for some form of accessory apartment. Yet many owners are not aware of the possibility of sharing their unused space with a renter and for those that do often the bureaucratic hoops, such as obtaining a special permit, are just too cumbersome.

A comprehensive zoning reform bill that passed the state Senate but not the House included a widely supported provision to allow accessory dwelling units – in specific situations – in all communities statewide as of right. If this legislation passed, when the ADUs and the properties met the requirements the applicants could not be refused.

Basically, it said: No community could prohibit accessory dwellings in an owner-occupied single-family house on a lot of more than 5,000 square feet as long as it includes sleeping, cooking and sanitary facilities, maintains a separate entrance (from inside or outside), and the unit is under 900 square feet. That bill is expected to be taken up again early next year in the new session of the Legislature.

About 14,000 new housing units are created in Massachusetts statewide annually, and conservative estimates note that 1,000 to 2,000 additional homes could be created if rules for ADUs were standardized, special permits not required, the option made more widely known, and (even better) if incentivized in some manner by municipalities.

Newton officials have decided that expanding its number of accessory units is a low-impact way to offer relatively modestly priced housing while providing homeowners with a little extra income and possibly keep them from having to move. Many communities know that there are spaces being used unofficially as ADUs in single- and two-family homes. Making the law clearer and easier to comply with would allow ADUs to be better regulated and presumably safer.

While the city of Newton allows lodgers in a home occupied by the owner, under its proposed bylaw an ADU has to have certain features to qualify. Those include a dedicated entrance, a bathroom and a kitchen. As in other communities, different rules would apply to ADUs in detached structures, such as an apartment built over a garage or carriage house. Newton’s City Council is set to decide on the issue by February.

The Metropolitan Area Planning Council has said that more than 400,000 new housing units will be needed by 2040. According to advocates like the Massachusetts Smart Growth Alliance, accessory units benefit a municipality, local employers, homeowners, families, seniors and young professionals.

ADUs alone won’t solve our housing problems, but many see ADUs as “a tool in the toolbox.”

But their unique advantage is that they – or at least their potential – already exist in your neighborhood. Let’s ensure that statewide legislation that allows and incentivizes ADUs gets passed this year. It is simple idea that can have important effect.

Susan Gittelman is the executive director of B’nai B’rith Housing, a nonprofit, affordable housing developer currently working in Boston, Sudbury and Swampscott.