Susan Gittelman

Massachusetts’ housing crunch continues to worsen, with the number of available units lagging more than 100,000 behind demand. There’s rarely a silver bullet solution to such a crisis, but state action to allow accessory dwelling units by right would clearly narrow the gap between supply and demand, and reduce housing costs. 

ADUs, also known as in-law apartments, are dwellings that are either attached to or detached but on the same lot as a single-family home. They must have their own entrance, include a bathroom and kitchen and meet all local safety standards. 

ADUs are usually small and affordable. They use existing land to create more housing, layering in density without changing the fabric of single-family neighborhoods.  

In Massachusetts, each municipality currently determines whether to allow ADUs and what restrictions to place on them, and the result is a confusing regulatory patchwork. Some communities don’t allow them at all. Others allow them to be occupied by caretakers or relatives of the homeowner but prohibit their use as rental property and require that the unit be removed when the relatives or caretakers move out.  

Still other Massachusetts communities allow ADUs, but restrictions like exorbitant lot size requirements and parking space thresholds mean that only a fraction of single-family homes are eligible. In Manchester-by-the Sea, they can only be on lots that are at least twice the size allowed for single-family homes and only where houses were built before 1984. Weston requires any single-family home that is altered to include an ADU have at least 3,000 square feet of living space. The ADU must have at least 600 square feet of floor area, but if it’s attached to the home it can’t exceed a quarter of the dwelling’s habitable area. 

California Shows ADUs’ Potential 

Though long dismissed as not being impactful, the development of ADUs would indeed generate significant additional housing that can meaningfully ease the housing shortage in a low-impact way. Seattle adopted ADU reforms in 2019 and by last year permitted just under 1,000 units, volumes which were more than triple the typical pre-reform level. California legislation allowing ADUs by right took effect in 2017. By 2022, roughly 1 in 7 homes permitted in the state was an ADU, and in Los Angeles it was 1 in every 4 homes.  

Massachusetts legislation to allow ADUs would help ease the crunch by facilitating the growth of an industry that could deliver units at scale. It would eliminate the need for homeowners to go through a lengthy permitting process that may include contentious public meetings and can cost upward of $10,000. Builders could achieve economies of scale that would allow them to deliver housing units less expensively.  

Bequall is a company that manufactures ADUs, which are then delivered to a lot and hooked into municipal utility services. The 380-square-foot units include high-quality finishes and modern appliances. They are designed for individuals and couples, who make up about half the rental market. The company’s co-founder, Scott Bailey, used to live in the Boston area. He’s looked at the local market but found that just two Massachusetts communities would currently permit his product. He’s now working in California. 

Social Benefits for Seniors, Families 

Allowing ADUs by right statewide would also bring social benefits. It would, for example, help accommodate the nearly 20 percent of U.S. residents who live in multi-generational households, which can include grandparents who want to be around their grandchildren or children in a first job trying to achieve financial independence. 

ADUs are especially helpful for seniors wanting to age in place. In addition to providing extra income for those who rent out an ADU, it gives seniors wanting to downsize the option of moving into the accessory units and renting out the main home. 

The time has come for Massachusetts to act. Last summer, an economic development bill that would have cleared the way for more ADUs failed to pass in the waning days of the legislative session. This year, state legislation known as the YIMBY (Yes in My Backyard) Bill (H.1379) would allow ADUs by right in all communities across the state.  

Accessory dwelling units would increase the housing supply and help moderate prices without changing the character of neighborhoods dominated by single-family homes. Perhaps Amy Dain, a consultant and public policy researcher who studies zoning, put it best when she told the Boston Globe that “ADUs are the… low-hanging fruit. All we’re really talking about is letting people use their existing properties to create more housing.”  

It is hard to find cause for argument in that.   

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