Requirements for GC Estimator or (Quantity Surveyor ) are as follows.An Estimator works for Contracting Co. He/she :Checks Bid Plans and Specs ( Tender Documents )Takes off all Quantities or Items of Work for the Project including specific Items affecting prices.Uses the Rates available or gets prices from Subcontractors.Prepares Competitive Bid as a Contractor which will have Bill of Quantities/ Rates /Any other Special Features related to Specific Contract with Exclusions if any.