When Cambridge passed its first zoning laws in the 1920s, proponents framed zoning as a scientifically motivated policy to protect the living conditions of all Cambridge residents. They dismissed concerns that zoning would bring about segregation on the basis of race or income or that it would contribute to a housing shortage. Within a couple of decades, though, the justification for tighter zoning restrictions shifted from protecting access to open spaces and preventing fires to ensuring that some neighborhoods would remain exclusive and wealthy. Courts have long held that explicit segregation by race through zoning is unconstitutional, but do not apply the same standard to zoning rules that made housing more expensive in certain neighborhoods. Over the decades, Cambridge residents enacted increasingly restrictive zoning rules in the city, and particularly in neighborhoods where most residents were white and wealthy.
Importantly, many homes in Cambridge were built before this first zoning ordinance, and it has been amended several times since to add additional restrictions on new homes in residential neighborhoods. The result is a zoning ordinance that does not reflect our city’s values or its built environment; it would be illegal to build a large majority of Cambridge’s homes today.
We're now reaping the consequences of those restrictions: more traffic, higher rents, and widespread housing instability. Many car trips on Cambridge streets stem from non-Cambridge residents driving to or from their jobs in or beyond the city because they cannot afford any of our limited supply of housing. Combined with high demand for housing of all kinds and at all price levels, tight zoning restrictions have created housing instability not just for low-income families, but even for workers with much education and well-paying jobs.