The cost of building a foundation varies greatly depending not only on the type of foundation in question, but also on the location where the foundation is built. Like most building costs, the cost of a foundation fluctuates from region to region, and the overall cost of a particular foundation will be influenced by both the complexity of the job and the local building market.
Factors that cause the cost of building a foundation to vary from location to location include local variations in material and labor costs, as well as common practices in a particular location. When one specific type of foundation is more commonly built in a particular location than other types, local contractors are typically better equipped to build that type of foundation than they may be elsewhere, resulting in relatively lower costs. On the other hand, when a particular foundation type is rarely built in an area, contractors may be less well equipped to build it, and the cost of building that type of foundation will be relatively high.
A slab foundation consists of a flat, cast-concrete slab that rests on a perimeter stem wall, which in turn rests on a below-grade footing. The cost of building this type of foundation includes excavation of the site, grading of the site and the addition of a gravel base layer beneath the slab. The budget will also include material and labor costs associated with building forms for the concrete, casting the footers and stem wall, and pouring and finishing the slab. At the time of publication, the cost of a typical slab foundation for a home between 1,600 and 1,800 square feet ranges between $7,000 and $16,000.
A perimeter foundation consists of a perimeter stem wall resting on below-grade footings; the walls and floor of the structure rest on the stem wall. Costs associated with a perimeter foundation include excavation and grading, along with the construction of forms for casting the footers and stem wall. In some cases, the stem wall may be built with precast concrete blocks, which will lower the cost of forms. At the time of publication, the cost of a typical perimeter foundation ranges between $18,000 and $21,000.
A full basement foundation consists of footers, a slab basement floor and stem walls that extend the full height from the basement floor to the level above grade where the building’s main floor rests. As with other foundation types, the cost of a full basement foundation includes the cost of excavation, grading and forms, but because deeper excavation is required, excavation costs will be significantly higher. Additional cost considerations for basement foundations include the cost of drainage systems, waterproofing and concrete reinforcements in the cast basement walls.At the time of publication, the cost of a typical full-basement foundation ranges between $13,000 and $30,000.