Construction of a raised floor helps accommodate the scheduling of trades, and expedites construction. For example, concrete and masonry work does not have to wait on plumbing installation and inspection, which is the case with slab-on-grade.
Changes to the floorplan, such as relocation of a toilet or lavatory, are simple and economical compared to slab systems.
A raised floor can be a cost-effective solution to construction in poor soil conditions, where movement of expansive clays or the subsidence of organic soils is a concern.
Reduced Cut and Fill
For sloped lots, a raised floor on piers can be more economical and practical than building a “cut and fill” slab foundation. Less soil is disturbed, reducing erosion. The piers eliminate the need for reinforced retaining walls and other extraordinary measures to provide proper site drainage, and plumbing connections to city services may be simplified.
Flooding is always a concern. Raising a slab with fill to meet minimum flood-zone elevation can be expensive, time consuming, and difficult to properly compact. A raised floor system provides a practical and affordable solution for meeting code requirements in flood-prone areas (see Reduced Flood Risk).