Foundations and Basements
Slab on grade or crawlspaces, which is better?
...in the future. And it should go without saying, but be sure to make a clear map of where those features are.
Plumbing durability and maintenance: electrical wires need to be in conduits under slab foundations to meet building code in most regions (we hope), but putting plumbing lines in conduits is also a good idea; ...