On both sides of the urbanism argument, it is fashionable to worry about the details of how density is implemented. The right worries how “impacts” will be “mitigated,” as if density is an infection to be contained; the urbanist left is very interested in street interface, shadows, store widths, accompanying parking, and so on. After all, no one wants to have a simplistic view of a complicated issue, everyone wants to prove their Seattle bona fides with a complaint about what developers are doing, and the art of good design is much more interesting to write about than the science of stacking units on top of each other.
While all that stuff is important, I’m here to speak up for the utterly simplistic, spreadsheet-gazing practice of just considering how many net units a development is going to bring to the city.
Consider the overwhelming benefits of more housing in the City of Seattle:
- Fewer vehicle miles traveled, resulting in less energy usage, air pollution, and run off into the Sound.
- Less farmland and virgin forest destroyed for new housing.
- More legislative representation and better treatment of urban issues in Olympia.
- More time in congested central cities, where vehicle speeds make fatalities rare.
- Less competition for existing affordable units.
- More economic activity both in construction and in the businesses spawned by new units
- A larger tax base for large capital projects (like light rail) that benefit everybody, as well as social programs
Moreover, there is the fundamental moral issue of turning away as few potential Seattle residents as possible. While it’s a tragedy every time a low-income person can no longer afford to live in Seattle, it’s also a shame when the failure to build housing forces a newcomer out of the city.
Now obviously this logic can be taken to absurd extremes. I’m on the urbanist left and sympathetic to the aesthetic and parking concerns, even if they’re overemphasized relative to raw population counts. It’s clearly not a good thing when a 60 unit low-income building with no parking and narrow storefronts is replaced with a slightly larger building with 62 luxury units, lots of parking, and blank walls at sidewalk level. For one thing, the low-income residents will have much more trouble coping with displacement. For another, injecting all those cars into the system will create many negative externalities.
But that is a rare and extreme case. When a project eliminates old housing stock at all, it typically replaces the units at a very high ratio. Pushing for sensible accompaniments to density is worthwhile, but not to the extent of severely curtailing the number of units built.