Who's Responsible for Job Surprises? by Reina A. Calderon, Esq. Contractor A contracts with Owner B to erect a building on a certain lot and finds that he must excavate through more rock than he anticipated, substantially increasing his costs and the time he needs to complete the foundation. Can Contractor A shift his increased costs to Owner B without amending the construction contract? Contractor C engages to demolish a building built after the date that certain asbestos materials were prohibited, and finds that the building contains asbestos, requiring him to comply with certain federal and state standards regarding worker protection that increase Contractor C's costs substantially. Can Contractor C recover for the increase in his costs from Owner D? The answer given to