We have two parks in Wisconsin with a large number of vacant lots. We are going to be bringing in homes if we close. Concrete slab cost can add up, so we are looking at Frosted Protected Foundation Design approved in WI. I understand this to be basically putting non-frost susceptible soil under mobile homes with vapor barrier. This sounds much more affordable than concrete slab. I wanted to see if anyone has experience with this. If so, I would love to hear how the experience has been.