The building codes are likely very different. Think about a shopping mall and the idea of converting it to cheap housing. All of the plumbing and electrical i

The building codes are likely very different. Think about a shopping mall and the idea of converting it to cheap housing. All of the plumbing and electrical is for stores - maybe 1 sink per small store and department/anchor stores have 8 bathroom stalls all in one area. Then you have the fact that these buildings were likely constructed using asbestos in various ways. Gutting the interiors entirely is necessary, maybe they even need to gut major areas of the building to support more utilities as well. It’s probably not cheap so affordable housing may not be in the equation afterwards because of the renovation costs.