Crawl spaces
Should I Build on a Slab on Grade Foundation or a Crawl Space?
...foundations to meet building code in most regions (we hope), but putting plumbing lines in conduits is also a good idea; that way, if for any reason at all you need to replace a waterline, you simply pull the PEX out of the conduit and replace it. An additional feature I once saw that made a lot of sense was a second b...