Foundation backfills on a small lot can be a tedious and time consuming project. The biggest factor when it comes to a filled raised foundation is if the slab is a structural slab or not. If you are dealing with a structural slab you can cut your fill time down with lower compaction ratings. If it is not a structural slab then its most likely the case you will need to pull regular compaction densities in the 90 to 95 range.
Lucky for us on this project we are dealing with a structural slab that even cantilevers off the foundation 5 to 8 ft in some areas. This is not your average foundation design and what your seeing is the foundation for a very modern style home.