Translation:He resides in the basement under the house.
Because basements are always under the house - sort of. Saying "the basement" AND "under the house" seems unnecessary and conflicting. And actually, basements are just the bottommost portion of the house itself, so saying that it's "under" implies that it's separate in a way that it is not. Some might even say that a phrase like "under the house" would imply you've got a body buried there...because no one LIVES "under the house".
You could say something like: "we live on the main floor, and my brother lives under us in the basement." Or: "the basement is under the main floor."