CO
Change Order
A Change Order (CO) is a formal, signed amendment to a construction contract that modifies the original scope of work, contract sum, or contract time. Change orders are the primary mechanism for documenting and pricing changes that arise during construction - owner-directed scope changes, design clarifications that affect cost or schedule, unforeseen site conditions, or errors and omissions in the original construction documents. Every change order is typically initiated by a Change Order Request (COR) or Potential Change Order (PCO) from the contractor, reviewed by the architect or owner's representative, and executed only when signed by the owner, architect, and contractor. Once executed, the CO becomes part of the contract and updates the contract sum and substantial-completion date accordingly. Change orders are distinct from Construction Change Directives (CCDs), which authorize work to proceed before pricing is agreed, and from Architect's Supplemental Instructions (ASIs), which clarify documents without changing cost or schedule. The AIA contract documents (A201 General Conditions, G701 Change Order form) define the standard process used on most US commercial projects.
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