Bathroom addition and plumbing

[Thoff]

I'm wanting to bumpout my master bath about 50sqft. The bumpout part will be built off of the external wall. I plan to just make a walk way/door for the water closet and shower so that I do not have to tear down much of the load bearing wall. I have a crawl space. The toilet will probably be about 4 -6 feet away from where I would like to put it in the bumpout. How would a plumber connect my new plumbing to my existing plumbing? Will they have to cut through the foundation? Or can they go through the joist/header on the crawl space? I would just need plumbing for the toilet and shower. Thanks