[anotherthrway]

Luxury conversions - 2 apts max per floor? — could address the single shared utility risers/core of the typical office building. Schematically: [ a | util | b ].

Malls are also on the table for conversions these days. That is a much simpler transformation.

[claytonjy]

Why are malls simpler to transform? All the malls I'm familiar with have relatively few bathrooms per floor, and huge interiors (low wall:floor ratio) that would seem hard to slice up into apartments.

[anotherthrway]

Was discussing the same with dad when walking through a nearly abandoned mall in MD a while ago. Think a sort of gated community - anchor stores can become things like WholeFoods. Reclaiming a ribbon of parking around the mall allows for creating a green zone around the mall and possibly even ‘backyard’ gardens. And as noted by others, it is far more trivial to add the necessary infrastructure to support housing. Natural light is another issue which can be addressed with minor alteration to the external facing walls of stores. Basically you can easily stamp out big studios, merge stores for n-bedrooms, and depending on the structure of the mall possibly even punch through floors for duplexes, etc. These will be luxury units. And the ‘food court’ etc. can form the core of the ‘village’.

[jnwatson]

It is far easier to add plumbing to the ground floor of a building. In fact everything is easier if you’re not 1000 feet in the air.