What document does the Architect issue to confirm Substantial Completion?

The document that the Architect issues to confirm Substantial Completion is the Certificate of Substantial Completion. This certificate is significant within the construction process as it serves as an official recognition that a project has reached a stage where it can be occupied or used for its intended purpose, even though some minor work may still remain.

Issuing this certificate signifies that the work has been completed in accordance with the contract documents, allowing for the owner's occupancy while also delineating responsibilities regarding pending items. It can also trigger various important processes, such as the commencement of warranty periods and adjusting the liability for insurance and maintenance responsibilities between the architect, the owner, and the contractor.

In contrast, the other documents listed have different functions: a Final Payment Application pertains to the request for the final payment from the contractor, a Construction Change Directive is used to authorize changes in the work without prior agreement on the amount of adjustment in the contract sum or time, and an Architect's Supplemental Instruction provides the contractor with additional information or clarification on the project without changing its scope. These do not serve to confirm Substantial Completion specifically, underscoring the unique role that the Certificate of Substantial Completion plays in the construction process.