I believe the houses are not setup as placeables on the map so the only way to delete them is via Giants Editor. Sorry about that.
No problem! Easy enough to spend 20 minutes going through and deleting them. Great map none the less.
Question for you, while removing the houses I am unable to find where to remove the cars in the driveway, I wasn't able to find them in an .xml or in GE, I think I am above my skill grade on that portion, any insight?
Try deleting these objects in Giants Editor..I think these might be what you are looking for