The crew put foam board on the foundation walls to protect the wall and waterproofing from being damaged by the gravel and dirt back fill. Here you can see the foundation drain pipe in place. It's the kind with holes on the bottom. (How does pipe with holes on the bottom drain water from the house? This kind-of explains it.) This is 4" pipe. You can also see the landscape fabric which will help keep soil from clogging the pipe.