There was a window a few years ago when Portland allowed developers to construct large apartment buildings without any parking. But even in Portland there’s pressure to subsidize cars at the expense of housing affordability.

In 2013, city leaders decided to require at least one space per five units in buildings with 30 or more apartments. Larger buildings required at least one space per three units.

Now the city is considering expanding parking requirements in northwest Portland. Michael Andersen at Bike Portland is sharing an informal analysis from a local affordable housing advocate who found that it was cheaper to build homes in Portland when parking wasn’t required:

Portland affordability advocate Brian Cefola got in touch with us last month to share the numbers he’d crunched using local building permit data published by the U.S. Census.

It turned out, Cefola discovered, that the average cost of building a home in a Portland multi-family building dropped 24 percent between 2011, when Portland’s first wave of no-parking apartments began to open, and 2013, when the new city rule took effect.

At that point, the average price returned to its previous levels.

Cefola’s analysis comes with some big caveats. City Observatory’s Joe Cortright told Andersen the data is too “noisy” to draw any firm conclusions. If housing construction was concentrated in a more expensive part of town some years, that could explain the higher costs during that time, for instance.

But the data suggests that, at the very least, Portland should take a closer look at how parking requirements are affecting housing prices. Expanding minimum parking requirements to new parts of the city could have big implications for housing affordability.

Elsewhere on the Network today: Whether you recognize it or not, zoning controls your life, writes David Walters at Plan Charlotte. The Transportationist explains how a bike lane with as much traffic as a car lane may appear to be “underutilized.” And Transit Center compares attempts to regulate Uber, Lyft, and similar services in Chicago and New York (spoiler: Uber’s sky-is-falling objections to stricter licensing don’t seem to be valid).