Which document allows for the Commencement of work in the project?

The Notice to Proceed is the document that directly authorizes the contractor to start work on the project. This notice is typically issued by the owner or the owner's representative after all prerequisites, such as contract execution and insurance verification, have been fulfilled. It signals that the contractor can mobilize resources and begin construction activities as defined in the project schedule.

The other choices relate to different aspects of the contracting process. The Notice of Award confirms that the contractor has been awarded the contract, but it does not permit the commencement of work. A Contract Change Order modifies the terms of the existing contract, but it does not serve as a signal to initiate work. The Certificate of Substantial Completion indicates that the project is substantially completed, but it is not a document that starts the work; rather, it recognizes that the project has reached a certain level of completion according to the contract specifications. Thus, the Notice to Proceed stands out as the specific document that allows work to commence.