Beneath each of the foundations, we have some little lintels to form a tunnel at each end of the foundations for drain pipes to pass through.

You can see one in this photo above – this one under the dining room extension.

This one I think is for the new soil pipe at the south west corner to traverse down to the main drain function.

This tunnel though at the south end of the family room has no pipe running through it.  I thought though that the main north-south main drain would run through here. It’s not visible here so I must learn from Nick how this works.