More regarding office to apartment conversions

 So, unless there was room outside of these buildings to add extra supports and often there is not because office buildings in places like New York and Chicago are often right next to each other what they are doing is downright dangerous to anyone in those buildings or nearby.

So, without the extra engineering supports which might not be possible in these situations what they are doing is likely very dangerous because these buildings were never built with this much weight in mind and so supports will tend to collapse under the extra weight they were never engineered for in the first place as office buildings.