Older Buildings, New Housing?

I live in a rather lovely suburb of Rochester, New York, but I travel into the inner city every week to work on a couple of my retirement "jobs". There's a lot that's not pretty in the inner city, including many vacant larger buildings that were once offices or used in light industry.

Housing is a real issue in the inner city, and energy costs are high in New York. So it seems to me that these older buildings might have promise as housing for lower income people. With efficient layouts, soundproofed interior walls, and a low percentage of exterior wall exposure to interior space, these buildings might provide decent apartments with reasonable utility costs. I wonder why they're not being gutted and converted?

The primary alternative for people with lesser means is much older housing with poor insulation, lead paint exposure, and inefficient utilities. Is this a decent alternative?

I think of younger people in Manhattan, living in relatively small spaces that have breathtaking rents. In the larger cities of Europe you see much the same, except that rents fall as the train rides get longer. Why are we so focused on single family housing? Habitat for Humanity houses are nice, but they are really expensive when all the costs are figured in.

Maybe we should renovate the solid older buildings into lower income apartments and tear down the blocks of decrepit older homes. The open space could be used for parks, transportation hubs, and schools.

My guess is that building codes, zoning requirements, and the interests of slumlords are taking precedence over common sense utilization of structures that were built to last a long, long time. Why is it that these buildings just sit, unused, year after year?