So my wife and I had a home inspection on a lake house we're looking at purchasing. During the inspection we realized that a 12' x 15' room they added is only sitting on a 4" slab. No foundation. I know in MI we need a foundation four feet down. My question is has anyone ever dealt with a situation like this? The soonest we can get someone out to look at it is in 4 days. Anyone have an idea how much it might cost to get a foundation under this room? Talk about an unhappy day.