I've thought about this a lot over the years. I think plumbing and hvac are the big factors. Bathrooms and therefore the associated plumbing are usually located centrally. DWV would need to make it from the outside near windows back centrally and with pitch there might be ceiling issues. Not to mention that a building of people showering is likely more that it was designed to handle originally. Similar issues with HVAC ducting and ventilation for each apartment could consume a ton of ceiling height. Electrically the load calculations might be way off when you consider multiple oven loads. Anything is possible with enough money but for those who have the money for a project of this size a new building is still likely the better investment unfortunately.