The legal test
In Mears Ltd v Costplan Services [2019] the Court of Appeal summarised the position: practical completion is reached when the works are complete and free from patent defects, other than ones to be ignored as trifling. Whether a defect is trifling is a question of fact and degree, judged against whether the building can be used as intended. Latent defects, which nobody knows about yet, can’t prevent it. Unfinished work and defective work are treated alike.
What practical completion triggers
- Release of half the retention (see retentions).
- Liquidated damages stop accruing (see liquidated damages).
- The rectification period starts.
- Insurance and security often pass to the client.
- Final account and time limits for some claims start to run.
Practical tips
- Contractors: agree a snagging process and target date early; give notice when you consider practical completion achieved.
- Clients and administrators: certify when the test is met, not when everything is perfect; list outstanding items; don’t withhold the certificate for leverage.
- Everyone: record the building’s condition at handover with photos.
More in our contract administration guide.
General information, not legal advice. What applies to you depends on your contract, the facts and where the work is, and the law changes. Check the sources below and take advice from a qualified professional before acting on anything that matters.
Last updated: 7 October 2026
