General Contractors don’t value engineer anything unless they are part of the design team. Especially with commercial work. Even then they are the low man on the design team and are basically being asked “if we go with this more cost affordable material what’s that gonna do to the labor because it’s cheaper and more of a pain to work with?”Architects, Engineers, designers, and The Client do value engineering and design. Usually at the request of the client. The general contractor and all the subs work with the materials spec’d by the design people and assemble/install them according to manufacturers instructions and local codes. And there are even specific fastener specifications and spacing for the Sheetrock/drywall/gypsum board. GCs primarily facilitate the construction of a given project. They and the subs have latitude with very small things as long as the aren’t going against what’s on the plans. If something isn’t gonna work according to the plans there are meetings with the guys who drew the plans to work out solutions. If changes are to be made to accomplish the the overall vision Change orders are submitted on every level for approval before materials are ordered or work is done. The only “control” over costs that the General Contractor really has is choosing which vendors, suppliers, equipment rental companies, and subs to negotiate price with and to use in the first place. Sent from my iPhone using Tapatalk