In a slab-on-grade foundation, also known as monolithic slab construction, the floor slab and footings are poured simultaneously to form an integral unit. The concrete slab is placed directly on the ground, with plumbing pipes, electrical work, and ductwork running underneath. Slab-on-grade works well with the passive solar designs and radiant heat floors popular in Santa Fe, where I build custom homes. And compared with a stem wall with footings, slab-on-grade foundations can save money, especially for simple buildings with few jogs or ells. The footing excavation for a slab-on-grade is shallower, the forms are simpler, and there's no floor system to frame. If a building site is level, and the soil is easy to excavate but will hold
