Generally in a negotiated situation, the door is wide open when they look good to their superiors by recommending your company. Select and negotiated projects take more work on your part to locate, but the reward comes job after job, year after year. On plans, wallcovering details are often not clearly marked. It is a rare architect who provides a wallcovering finish schedule, elevation drawings, and floor plan. All three are essential for an accurate takeoff.
Most plans specify confirming all dimensions onsite.
However, a site visit may not be possible if the project is just coming out of the ground. Unless you like providing this kind of blanket coverage for their errors and omissions, never sign any document committing you to per plans and specs. In fact, standard paperwork from general contractors would require a lawyer to decipher and is often heavily weighted toward their benefit. To adequately protect yourself, use your own contract specifying a detailed scope of work, listing all operations and any materials supplied. Lynn Fife's outstanding book Guaranteed Profits in the Painting Business illustrates how to write your proposal to avoid the per plans and specs trap.