Abstract: A foundation system (1) and method of installing the foundation system. The system including plurality of modular slabs (3, 3A, 3B) mountable onto a gravel layer (2); and at least one horizontal isolating slab (5A, 5B, 5C) and a vertical edge portion (4) positioned with respect to the modular slabs (3A, 3A, 3B) for creating a receptacle wherein concrete is poured thereon.