The company that put in our modular home did not put our home below the frost line. Secondly, our land was not leveled properly, so the run off from the street and other neighbor's yard tend to accumulate in our back yard and under our house. We added more fill, which helped, but was advised that we could not add more, or we would have run off go into our adjoining neighbors yard, and they would face the same problem that we currently have. We thought of putting in a french drain on the low spot of our yard to take care of the run off. However, we are not sure how to handle the frost line problem. Does anyone have any suggestions. We have thought of a basement, but not sure.