Explaining Massachusetts’ New TOD Law

Writing in Commonwealth Magazine, Amy Dain explains Massachusetts’ new MBTA Communities law, which requires “cities and towns served by the MBTA (outside of Boston) to zone a district “of reasonable size” for multi-family housing near MBTA stations, where practical.”

Dain describes the measure used by the state to calculate ‘reasonable size,’ what the state calls “minimum multi-family unit capacity” or zoning capacity. “If you draw a zoning district for multi-family housing (defined as buildings with three or more dwelling units) on a municipal zoning map, you can add up how many housing units in multi-family buildings could theoretically and maximally be built on every existing parcel in the district, based on what the zoning allows, regardless of what exists on each parcel or what the market might favor for each parcel. This count yields the zoning capacity of the district for multi-family housing,” Dain writes.

Notably, “Zoning capacity is not a home production goal,” but “a legal envelope of allowed buildings; an estimated count of technically allowed dwelling units.” Requirements for each community will vary based on the type of transit present, existing density, and other factors. “A district that is reasonable in one city or town may not be reasonable in another city or town, the guidelines explain.”