Construction projects have been described as organized chaos. Architects and engineers, who admittedly do not know everything about the complex systems they are designing, work with both traditional and new materials to develop a design that mostly meets the requirements of the owner. Invariably, during the course of a construction project, discrepancies are discovered, preferences change, or conditions are found that are not accounted for in the initial design. Any of these may lead to change. If this change leads to a change in the scope of work for the general contractor or subcontractor, or it has a significant impact on the timeframe of construction, change orders will be required.
In all the standard contract forms from American Institute of Architects and in many of the contract forms from ConsensusDocs as endorsed by the Associated General Contractors of America, there are specific references to scope changes and change orders. And because most conditions have been experienced before, and there has been litigation on many of these, contractors and designers can anticipate the form of most of these changes.