The article goes into this:

> The city of Seattle estimates that, with aggressive incentives, conversions could generate up to 6,000 housing units over the next seven years. At a rough approximation, that would use around a fifth of the city’s present office surplus.

> But “potential” is doing a lot of work here.

> Newer, larger office buildings, like the U.S. Bank Center, are hugely impractical for conversion, thanks to massive floor plates, centralized plumbing and other utilities and a host of other constraints.

> The preferred candidates are typically smaller, older buildings, especially those with C- or E-shaped floor layouts, which make it easier to create smaller units with adequate windows.

> But these buildings can be prohibitively costly to bring up to seismic and energy building codes, said Jen Pasquier, a Seattle developer who wants to convert the 10-story Liggett Building, at Fourth and Pike, into 93 apartments.

There have been some attempts to convert office buildings with large rectangular floors into long, narrow apartments so every apartment has a window. It's possible, but difficult.[1]

Plumbing and sewerage turns out to be a huge headache. Large office buildings often have all the plumbing and sewerage in a small vertical core. The rest of the building is just flat slabs on columns. Adding a sewer line means punching through the floor and hanging pipe in the space above the apartments below. If you're in SF and want to see what that looks like, park in the 4th and Mission garage on the lower level, where you can see the plumbing from the restaurants above hanging from the ceiling. Also, sewer lines are gravity fed, with a 2% slope typical. Long pipe runs get lower along the run, so you probably have to put them along a wall. Then you have to hide and soundproof that stuff, although you might be able to get away with leaving it exposed if you market to hipsters or sell it as low-income housing. If the original building has enough ceiling height, it's easier.

Then there's HVAC, exhaust ductwork for kitchens and bathrooms without windows, partitioning the electrical distribution for the individual units, fire breaks between units, etc. Overall, it's maybe 30% cheaper than a new building, and all custom work requiring experienced people. If botched, it can be more expensive than a new building.

One company that does such conversions admits they're building tomorrow's slums.

And then there's the fundamental problem that if jobs are leaving the downtown core, why have more housing units there?

[1] https://www.pbs.org/newshour/economy/analysis-heres-what-it-...

The regulatory process in Seattle is fairly painful, which raises the bar for even some of those smaller, older buildings. It'd help to change that, even though it wouldn't consume the majority of the surplus.

So convert those buildings to giant dorms. Lots of younger people would be more than happy with such an option (as long as it's priced accordingly of course)

Can also combine with capsule hotels.