What steps or actions should the architect and contractor have taken before committing to the specifications on the window units and spacing between granite slabs that would have prevented this problem?

Star-Board Construction (SBC) was the prime contractor for a large skyscraper project in downtown Manhattan. SBC worked directly from drawings received from the architect, Santaro Associates (SA). Robert Santaro, owner and chief architect of SA, viewed this building as similar to others he had designed, although one difference he failed to notice was the building’s facing, which was to consist of large granite slabs—slabs much larger than anything with which he or SBC had prior experience.