History of Cambridge’s Housing Construction

Christopher Schmidt
3 min readSep 28, 2020

I made a new graph today, and I was honestly kind of surprised by it. It’s “number of today’s existing units in various housing types, by decade built.”

Prior to the 1930s, we were creating lots of housing in 2-fam, 3-fam, and small apartment buildings. In the 1930s, that ended.

Units built by year; blue = single family, orange = 2-fam, green = 3-fam, red = 4–8 unit buildings, purple = >8 units

Over the course of the 1850s until the 1920s, Cambridge evolved from single family homes to modest sized apartments — 4–8 units — being the bulk of newly constructed units… And then it stopped.

Why? Well, there’s lots of potential reasons, but zoning was introduced in 1926.

It is really hard to take a look at the overall history of “when buildings that exist today in Cambridge were built” and not see a direct line from the introduction of zoning to almost a complete stop of new building construction.

Now, in the 1960s, we did start seeing more *units* created , after a lull of several decades…but the average number of units per building increased from 3 units in 1920 to 10 units in 1960, to *47* units in the 2010s: we’ve focused *all* of our development into a tiny number of new buildings, almost all in larger apartment or condo buildings containing more than 8 units.

You can see this in maps: in 1870, Cambridge built about the same number of *homes* as in 2010–2017, but comparing the maps of where they *are* shows that we drastically changed how we build in the city. crschmidt.net/housing/cambri…

On the left: where homes were built in the 1870s; on the right, where homes were built in 2010–2017.

It is really hard to not see this as a direct outcome of zoning rules designed very much to restrict new development of homes. While the depression and WWII had an influence on the city, overall, what we see is that this slowdown in construction meant *the city ran out of room*.

If we look at population growth, we see significant growth through the 1920s, but then it… stops. We bounce around a bit at about the same population as we are now, but that’s it; later, white flight takes over and we lose 25,000 residents.

Now, we’ve regained that population as Cambridge has recovered from a tough time in its post-industrial history… but we’re bouncing again.

From the 1870s — when Cambridge was just *39000 people* — to the 1920s, we built more homes every single decade than we did in the 2000s.

But it’s not just *number* of homes: it’s also *distribution and variety of homes*.
Many in the community oppose large developments like Market Central, or 400' housing towers near Kendall. These buildings are outside of our historical norms; they exist due to restrictive zoning!

Anyway, none of this is surprising at its core: I’ve seen these things before in pieces. But putting it all together, it tells a far more clear tale than I thought it would, supporting the concept that we banned the thing that many want to see: Creation of modest scale new homes.

To explore the history of development of housing in Cambridge, check out the new tools:

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