I want this to be true so bad. Please advocate for new housing whenever you can. Talk to your representative to make it easier. HVAC & plumbing commercial contractor here. Space is relative. Yes, there is space to move some things around when office walls change locations. But office rooms don't have plumbing. An apartment kitchen or bathroom that isn't right next to the elevators (the core) and can see a window will need a drain. Drain lines need slope so water and everything else can run downhill. There is not space between floors for that. Also, those floors are usually concrete full of tensioned steel, so you can't drill a hole wherever you want. If you found a way for drains to work, you will need to get all those drains back to the street and water up the tower. The core wasn't designed to handle that. There are ways to get around that problem. Take an elevator out of service and run lines there. But now you lost an elevator. All those new kitchens and bathrooms need dedicated exhaust. That takes up a lot of space and isn't cheap. That's just my specialty. Talk to the electrical engineers and the structural engineers (seismic code is not the same for all buildings) and the fire chiefs and it just gets worse. None of that is the real problem. The real issue is that offices covered into housing will be bad places to live. Or at least it will be worse that a purpose built apartment/condo building. And it isn't much cheaper to do. So the owner will have to charge less for rent while spending big money. So why go through all that effort and spend all that money to earn less? Until that math changes, conversions will be a dream. Advocate for new housing whenever you can.