The issue for today is tear down or reuse buildings.

I think it depends on how solid the structure is and if it's worth rehabing and keeping the building in place. The dewlling would have to be inspected in order to make the final decision. I would also think some of the decision would be made by the insurance company who carries the insurance on the building, providing it's insured. Last month there was a pretty nasty house fire on our street. By looking at the house it looked totally destroyed. Now I see there are several trucks fixing the house. The structure itself was still standing but everything inside was lost. The roof was gone and the carport completely destroyed. Guess it was cheaper for the owner to fix up the house vs. moving. Hopefully the stench from the fire won't be overwhelming when complete.

I think that cost should be a consideration unless the building has something historical about it.. Other then that, if it costs more to repair than to tear and build again, then tearing down would be the best thing to do..