Does the calculator account for soil testing and foundation type?

The calculator applies a soil factor that directionally reflects whether ground conditions are likely to be good bearing soil or weaker filled ground, but it cannot replace an actual soil investigation report for your plot. Weak or filled ground can push a project toward raft foundations, deeper excavation and additional waterproofing, all of which raise cost beyond what a generic estimate captures. Always commission a proper soil test before finalising foundation design, especially on plots near old tank beds or drainage channels.