A new concept finding it’s way into construction contracts is the so-called deductive differing site conditions (DSC) clause. This expanded version of the standard DSC clause provides for credits to the owner when the contractor encounters subsurface conditions that are better than the baseline conditions.

The standard DSC clause helps reduce the contingency allowances in contractor bid packages by relying on the geotechnical baseline report (GBR) for a definitive baseline of anticipated subsurface conditions.