The Prevention Principle and Time at Large: When the Employer Causes the Delay

The prevention principle is the rule that an employer cannot hold a contractor to a completion date that the employer's own conduct has made impossible to meet. If the employer causes delay and the contract gives no extension for it, the completion date falls away and time is at large.

Liquidated damages fall with the completion date, and the employer must then prove its actual loss.

That sounds like a powerful defence. In practice it rarely decides a modern dispute, because extension of time clauses, notice provisions and concurrency amendments are drafted to keep the completion date alive.

What Is the Prevention Principle?

The doctrine is old. In Holme v Guppy (1838), the employer failed to give possession of a Liverpool brewery site for four weeks, and the court allowed no deduction for late completion.

Jackson J stated its essence in Multiplex v Honeywell (No 2) [2007] EWHC 447 (TCC): the promisee cannot insist on performance of an obligation he has prevented the promisor from performing.

The leading construction authority is Peak Construction (Liverpool) v McKinney Foundations (1970) 1 BLR 111. A defective pile halted the work. The remedial piling itself took about six weeks, but the works were held up for some 58 weeks, largely because Liverpool Corporation was slow to approve a solution.

The extension clause covered variations and other 'unavoidable circumstances', which did not include the employer's own delay. Salmon LJ held that where both parties caused the late completion, the liquidated damages clause 'does not bite'. Time was at large.

Salmon LJ also gave employers the cure: an extension clause covering delay caused by the employer's own fault or breach. Legitimate conduct counts too. Jackson J held that an instruction the contract permits, such as a variation, can still be prevention if it delays completion beyond the contract date. Like other legal maxims in construction contracts, it rests on fairness.

What Does Time at Large Mean for Liquidated Damages?

Time at large means the contract no longer fixes an enforceable completion date. In Jackson J's words, later adopted by the Court of Appeal, the obligation to complete by the specified date is replaced by an implied obligation to complete within a reasonable time.

The liquidated damages clause stops operating because there is no date to count from. The employer keeps a claim for general damages, but only for delay beyond a reasonable time and only for loss it proves.

On a QAR 60 million contract with delay damages capped at 10 percent, up to QAR 6 million of agreed exposure is at stake. It becomes an argument about what was reasonable and what the employer actually lost.

Time at large is not a waiver of delay - it is a change in who must prove what. Before relying on it, estimate your liquidated damages exposure under the date the employer says still applies.

How Extension of Time Clauses Preserve the Completion Date

Extension of time clauses exist to stop the prevention principle operating. In North Midland v Cyden, Coulson LJ explained that they were not designed to give contractors excuses.

They protect employers by preserving a fixed, if extended, completion date and the right to liquidated damages after it. Hence Jackson J's second proposition: acts of prevention do not set time at large if the contract provides an extension for them.

FIDIC follows that model. Sub-Clause 8.4 of the 1999 Red Book, now 8.5 in the 2017 edition, allows an extension for 'any delay, impediment or prevention caused by or attributable to the Employer'. Variations and other listed causes also qualify.

Delay Damages under Sub-Clause 8.7 (1999) or 8.8 (2017) then run from the extended Time for Completion. On an unamended FIDIC contract, almost every employer delay has a home.

The argument revives when employers delete that ground or replace it with a closed list, recreating the gap that cost the employer its liquidated damages in Peak. Jackson J's third proposition then helps the contractor: an ambiguous extension clause is read in its favour.

Does the Prevention Principle Survive a Missed EOT Notice?

The argument runs that the employer caused the delay, the missed notice cost the extension, and the employer now charges liquidated damages for its own delay. A Northern Territory court in Australia accepted a version of it in Gaymark in 1999.

In Multiplex, a Wembley sub-contract dispute, Jackson J had considerable doubt that Gaymark represents English law. Notice clauses, he said, let delays be investigated while they are still current.

In his words: 'If Gaymark is good law, then a contractor could disregard with impunity any provision making proper notice a condition precedent. At his option the contractor could set time at large.'

He held that a contractor who could have complied, and simply failed to, does not set time at large.

Hamblen J reached the same result in Adyard, where the contract provided an extension for the events relied on and the claim failed for want of notice. A missed notice does not free you from the completion date.

It usually leaves you with the original date and the liquidated damages. Under FIDIC that is the 28-day notice rule at work, and late notice is a leading reason EOT claims get rejected. A claim can be valid and unrecoverable.

Can a Contract Allocate Concurrent Delay to the Contractor?

Under English law it can, if the words are clear. In North Midland Building v Cyden Homes [2018] EWCA Civ 1744, an amended JCT design and build clause dealt with concurrency. Delay from a Relevant Event concurrent with contractor-caused delay 'shall not be taken into account'.

Coulson LJ held that the prevention principle 'is not an overriding rule of public or legal policy' and that parties can contract out of some or all of its effects. The employer could levy liquidated damages for the concurrent period.

Without such a clause, English first-instance decisions under standard JCT wording have given the contractor a full extension for concurrent delay, as in Walter Lilly v Mackay (2012). The SCL Delay and Disruption Protocol takes the same view.

Where no extension ground applies at all, the answer changes. In Jerram Falkus v Fenice [2011] EWHC 1935 (TCC), Coulson J held that the principle does not help a contractor whose own concurrent delay would have prevented earlier completion anyway.

FIDIC 2017 leaves the point to the parties: the final paragraph of Sub-Clause 8.5 refers concurrency to the rules in the Special Provisions. Read them at tender.

A clause like Cyden's turns every concurrent window into liquidated damages exposure, which makes it a price item. Our explainer on concurrent delay shows how time and money split when no such clause exists.

Why the Employer's Act Must Cause Actual Delay

Adyard Abu Dhabi v SD Marine Services [2011] EWHC 848 (Comm) concerned two support vessels built at a shipyard on the Abu Dhabi shoreline. The yard missed its sea trials dates, the buyer rescinded, and the yard argued that design changes imposed or instructed in mid-2009 had prevented completion.

Hamblen J held that the principle 'necessarily means prevention in fact', not prevention on a notional or hypothetical basis. The act relied on must cause actual delay to the progress of the works. The yard's own expert accepted there was none, and the project was already in irretrievable critical delay. The rescission stood.

The problem is rarely proving that the employer did something late. It is proving that it mattered. That is a programme question, which is why a contemporaneous method such as windows analysis carries weight that a theoretical impact does not.

Does Time at Large Apply Under GCC Civil Codes?

Most GCC states apply civil codes that do not use the terms prevention principle or time at large. They reach related results through rules on fault and causation and a duty of good faith.

The civil codes of Qatar and the UAE also let a court reduce agreed delay compensation shown to be excessive, and the UAE's 1985 code went further, letting a court match it to the actual loss.

The outcomes differ too. An English-law tribunal asks whether the completion date survives at all. A civil-code tribunal is more likely to ask how much of the delay each party caused. Under local governing law, English cases only persuade, so rebuild the argument in the code's own terms.

When Time Goes at Large and When It Does Not

Under English law, the scenarios resolve like this.

In a live dispute, treat time at large as the fallback, not the plan:

• Notify every employer delay event within the contract period
• Prove its effect on the critical path
• Plead time at large only where the clause has a genuine gap

We review hundreds of extension of time claims across the GCC every year. The contractors who argue time at large hardest are usually the ones who missed a notice.

At CALIM, we test every delay event against the contract's extension grounds before anyone argues prevention. Our EOT claims consultants build the notice record and critical path evidence that make a time claim stand.

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