Legal issues of practical completion

The definition of completion arises out of an interpretation of the particular contract.

In four cases: The Lord Mayor, Aldermen And Citizens Of The City Of Westminster v J Jarvis & Sons Ltd and another [1970], H W Nevill (Sunblest) v William Press [1981], Emson Eastern Ltd v EME Developments Ltd [1991] and Walter Lilly & Co Ltd v Mackay & Anor [2012] the court gave some consideration to the definition of practical completion as used in the JCT forms of contract. It held, in essence, that works are practically complete when they are accepted as complete, and that an architect has the authority to accept works as complete where very minor, de minimis, work has not been carried out. However, an architect does not have authority to give a certificate of practical completion where there are patent defects in the works. 

It is likely that the definition of 'substantial completion' used in the ICE (Institution of Civil Engineers) forms of contract is more accommodating of incomplete works than the definition of 'practical completion' in the JCT forms. Keating on Building Contracts suggests that the relevant criterion for accepting substantial completion is whether the works have reached a state at which they are fit to be taken into use by the employer.

Use of the term 'completion' in the NEC (New Engineering Contract) form may be interpreted more strictly than 'practical completion' under the JCT form, especially where the client has listed those works which have to be complete before completion.

The Limitation Act 1980 fixes the period within which an action may be brought. In the case of a simple contract, this is 6 years from the date on which the cause of action accrued. In a construction contract, the cause of action for a defect does not normally accrue until completion, that being the date on which the contractor asserts that the works are substantially compliant with the contract requirements.