>Office buildings simply aren't built to allow plumbing access to each office, for example, so communal bathrooms will be needed. Can you also imagine the mess that a communal kitchen would create? Upkeep and cleaning costs would go up. Many landlords may likely have clauses in their mortgages that their prop

What are you talking about, I know of at least a dozen buildings that underwent conversions. They usually convert them in to large luxury condos, and quite successfully. They have less than ideal floorplans, but overall its very good.

Here is a recent example:

https://onewallstreet.com/the-availability/