Substantial completion is reached when:

• A. The Contractor completes all punch list items.
• B. The Owner issues a final occupancy permit.
• C. The Architect signs off on a certificate of occupancy.
• D. The work is ready for occupancy as determined by the Architect; it signals warranty start and closeout milestones, and final payment is due after remaining items are completed.

Answer: (D)

Substantial completion means the project is sufficiently complete so the Owner can occupy or use it for its intended purpose. This is typically determined by the Architect, who certifies that the work is ready for occupancy, even though minor items may remain on a punch list. Once this milestone is reached, warranty periods begin and closeout milestones are activated, with final payment typically due after those remaining items are completed and accepted.

Why the other ideas don’t fit: requiring all punch list items to be finished would set an unrealistically high bar for occupancy and contradict the idea of “sufficiently complete.” The final occupancy permit is a separate regulatory step issued by the building department, not the trigger for substantial completion. The certificate of occupancy is not the same thing as substantial completion and is typically issued by the building department, not solely by the Architect.