The building code rule that lets Seattle turn forgotten lots into housing

Fire officials and pro-density urbanists are often at loggerheads. This is especially evident in notoriously car-centric Los Angeles, where a firefighters’ union spent six figures opposing active mobility measures. The two camps can have different ideas of acceptable risks and priorities.

But Matthew Flaherty, a firefighter who has lived in L.A. his whole life, bridges the two worlds. He’s an advocate for affordable, transit-friendly housing. His struggle to find an apartment in a walkable...