Dispute on construction contracts

I have found that it is when there are contradictions between contract documents. While often there is a hierarchy established for interpretation of the documents (i.e. which document holds precedence over others) that is often challenged by the contractor for good reason. I find that 'Notes' and 'Equipment Lists' found on drawings are often the cause of disputes as they conflict what is in the technical specifications. Often 'Notes' are added and Equipment Lists updated by the Engineer at the last minute to include project-specific requirements and to avoid rewriting 'outdated overused Technical Specifications. . As the Technical Specifications usually take precedence over the Drawings, the dispute arises when the contractor finds the requirements of the Technical Specifications to his/her advantage and provides 'as specified' whereas the Engineer/Client desires what is called out on the Drawings. A short-cut taken by the Engineer causes this conflict. The rule of thumb should be never place performance criteria on drawings; they belong in the specifications and that is usually where they are. Equipment lists belong in one document only. Having said criteria in both places will often cause conflict and lead to a dispute.