Ground conditions are a decision, not a discovery

Most cost blowouts we see start underground, and most of them were knowable. A geotech report tells you what the drilling rig found at the points it drilled. It does not tell you what is between them. On a former market garden, an old dump, or anywhere the survey shows fill, the gap between those points is where the money goes. We dig test pits ourselves before we price. It costs a day of machine time and it turns a provisional sum into a fixed one — which is the whole difference between a builder carrying the risk and a client discovering it.