Saving time on a building project often means saving money, too. North Carolina builder Tim Robinson saves both when he can by starting a project with insulated, precast concrete foundation walls. The panelized system Robinson uses is insulated with R-12.5 foam and has steel studs with holes punched for wiring and plumbing. Once a gravel footing has been compacted and leveled, the foundation walls can be dropped in place. This type of foundation system often can be set up in only two days: one day for prep work and one day for setting the walls.