Years ago I worked for an organization in Atlanta sort of like Habitat for Humanity but a lot smaller. Our goal was to provide housing for low-income and homeless people (ironically enough, part of the job was rousting homeless squatters out of houses so we could renovate them so different homeless people could move in). For one of our projects, the boss purchased eight 1960s-era houses from near the airport and had them moved onto a plot in the neighborhood we were working in. Unfortunately, the boss was pretty clueless and it turned out these houses had been built with 2x3s instead of 2x4s and were no longer up to modern building codes. So we had to tear them all down to the floors - which it turns out were half-rotten anyway and had to be almost entirely rebuilt, so we got almost nothing out of these wrecks. The boss had bought them because they were only like $20K each (including the move) and would have represented a considerable cost savings had they been worth a shit.
For bonus point, two of the eight houses turned out to have been placed only 8 feet from the property line when the code called for a 10 foot minimum distance. So after rebuilding all eight houses, we had to tear one wall off of each house and shorten them by two feet, which made the already-small bedrooms into essentially walk-in closets.