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Make room for Granny, and other zoning fixes

A key change in draft legislation on Beacon Hill would allow owners of all single-family homes to build small accessory dwelling units — also known as granny or in-law apartments. Shutterstock / Air Images

As the population ages in Massachusetts, cities and towns across the state should make room for Grandma and Grandpa even in residential areas dominated by single-family homes.

Draft legislation now being circulated among state senators would make a slew of little changes in the state’s zoning law, which forms the basis of land-use regulation in virtually every municipality. (The City of Boston operates under different rules.) One key change would allow owners of all single-family homes to build small accessory dwelling units — also known as granny or in-law apartments — subject to the safety protections embedded in local building codes.

It’s a modest step back toward the kind of intergenerational housing that once allowed members of extended families to take care of one another. In today’s context, accessory units have new relevance for seniors who don’t want to live entirely on their own, or for millennial children who are living with their parents but would like a modicum of independence.


While it’s encouraging that individual cities and towns are beginning to liberalize rules for these units on their own, it’s clear that the state zoning law as a whole needs a tune-up. Allowing granny apartments is just one of the necessary correctives included in the draft Senate bill.

In the four decades since the last substantial update of the zoning law, some towns have used its provisions to fight all significant housing development, instead of trying to gently accommodate a modest amount of growth. Not coincidentally, much of the state is now in the grip of a housing shortage — evident in spiraling home prices — that hampers economic growth and discourages younger families from putting down roots in Massachusetts.

The zoning reform bill would take on both the symptoms and the deeper causes of the problem. Some towns want the option of enacting inclusionary zoning rules, which require developers of large real estate projects to sell or rent some units at below-market rates, and the zoning reform bill would give them explicit authority to do so. To promote more housing production, the bill would also extend the duration of building permits, nudge towns to designate at least some areas where multifamily housing would be allowed by right, and promote better master planning. And it would defang a common argument against development by allowing towns to charge builders for the impact of new homes on public infrastructure. Meanwhile, the new rule about granny apartments could free up a lot of larger single-family houses, by giving elderly homeowners more options about where to go should they decide to downsize.


The existing system of zoning laws in Massachusetts reflects certain mid-20th-century assumptions about housing policy: that it should promote individual homes for nuclear families, to the extent that it allows new home production at all; and that it’s better to err on the side of producing far too few homes than to allow development that could prove inconvenient later. Those assumptions warrant some reexamination now.

The reform bill takes into account the input of smart-growth advocates, real estate interests, and municipal governments — none of whom will get the entirety of what they might want if the measure passes. Builders of housing support more accommodating planning and zoning rules but are wary of inclusionary zoning programs and impact fees. Town officials like being able to lean on developers for impact fees and below-market housing but want to maximize their own authority to block construction when they deem appropriate.


But as housing prices continue to spiral in Massachusetts, some compromise is clearly in order. The Senate bill would promote growth at a steadier pace — and give the grandparents a place to live to boot.