Adding a basement to an existing house?

There is alot to consider I dug out my basement. First get bids to see what the pros think, talk to the permit dept. A few things, what is your water table, just because the neighbor has one does not mean there isnt a spring down below, you dont want a swimming pool. You need to jack, support and monitor house level almost daily to be sure you dont ruin it. You need to figure out how to put in a foundation while removing the old one and keep it jacked up. You need a permit or you can have your home deemed un live able. Its going to be 3x more work than you think.

I bought an extended family home. It was built in the 1800's. I bought it in the 1960's. My uncle had the neighborhood boys dig out the basement by hand during the depression. He was a retired submariner and had a little money. He was something of a nut. After I moved in, many of those kids, now my age or older, would stop by and tell me how much my uncle had done for them when they were growing up. That house had many challenges but I loved it.

Yes it can be done, but it is an amazing about of work. It would almost certainly cost more than moving to a home with what you want.

That would depend entirely on what you wanted the basement for. Additional space that does not need to be underground can be built much more cheaply on the surface. Cheaper still may be a second floor addition. But if what you need is a larger comfortable space for the family to sleep out a tornado warning or other physical threat then that is a different issue.

HAVING it done would likely cost more than moving. Doing it yourself, (where permitted) is just hard, tedious work.

Another option is just to jack the sucker up about 9 feet, and build another floor underneath, but that depends on whether the floor-plan works.