Substantial completion is the contract milestone where the project, or a designated portion, is finished enough that the owner can use it as intended. Some minor items can remain on a punch list. The architect typically certifies it, often on a form like AIA G704, and the certificate lists the remaining work and who is responsible for utilities, security and insurance from that date.
Why it matters
A lot changes at substantial completion. Liquidated damages usually stop. Warranties often start. Many contracts allow a reduction or partial release of retainage. Risk of loss may shift to the owner. Missing the date, or failing to document it, has real money attached.
Worked example
Illustrative: on Riverside Medical Center, retainage held at 10% stands at $3.1M when substantial completion is certified. If the contract lets the owner keep 150% of the value of remaining punch list work and the punch list is valued at $400,000, the owner holds $600,000 and releases $2.5M.
Common mistakes
- Not getting the substantial completion certificate signed and dated.
- Letting warranty start dates drift to final completion by default.
- Leaving the punch list open-ended, delaying final payment for months.
How os.construction handles it
We’re building substantial completion as a milestone that links to the punch list, retainage release and warranty dates, so the next steps are visible. It’s being shaped with founding contractors.