Yes, there's this "inversion" thing, where the structure's value is less than the land's market value. This leads to "teardowns", i. e., buying a perfectly OK house, tearing it down and replacing it with a much more elaborate house, even in downscale locations like Dearborn Heights and Inkster, MI.
The thing is that mortgage interest rates are at historical lows (I never heard of sub-5% rates until 3 or 4 years ago in 50 years of following them), and when the rates go up, people will have to sell their houses for less, because buyers won't be able to afford the huge monthly payments. And at the same time, new construction will have to be a lot cheaper to sell at all.