Most T2/T3 delay claims in the UK use the same method. Compare the baseline programme to what actually happened, calculate the gap, assert the Main Contractor caused it. Done.

Simple. Logical. And often torn apart in adjudication. Not because the method is wrong, but because Subcontractors apply it badly and the work behind it is missing.

That method is As-Planned vs As-Built. It is the most common form of delay analysis on UK construction projects. It is also the most commonly challenged.

 

The crude version, and why it fails:

Compare the baseline programme to the completion date. Calculate the gap. Call it delay. Assert entitlement.

This is a global time claim. The burden of proof is brutal. You must show:

• The as-planned programme was reasonable
• You did not contribute to critical delay in any way
• Every delay event along the as-built critical path entitles you to time and money
• There is no other way to demonstrate cause and effect
• You complied with all relevant contractual obligations - notices given, information provided, mitigation attempted, works prosecuted with diligence

 

Miss any one of those, and the Main Contractor's delay expert will take the claim apart.

 

The proper version, and why it works:

• Reconstruct the as-built critical path from contemporaneous records.
• Identify every delay event along that path.
• Use activity level variance to isolate where time was lost - and where it was recovered.
• Attribute delay to each party, including the Main Contractor, other subcontractors, and your own trade.
• Account for concurrency.

Done properly, APvAB can identify culpable and excusable delay side by side. It can show mitigation and acceleration. It can demonstrate causation without modelled programme analysis.

One important caveat: where a Subcontractor has worked significantly out of sequence, re-sequenced, or accelerated in response to Main Contractor-caused delay, the as-built critical path may not reflect what would have been critical absent those interventions. On complex sub-contract packages, that is a vulnerability the Main Contractor's experts will pursue. The analysis must address it.

Keane and Caletka put it plainly: "If applied correctly, the as-planned versus as-built approach can be one of the most convincing and reliable methods of delay analysis, without the need for any modelled methods of calculating delay."

 

The problem:

Most Subcontractors do not do the work.

They have no properly reconstructed as-built programme. They have no contemporaneous records to validate the critical path. They have a bar chart comparison and an assertion.

That is not APvAB. That is hope. And the Main Contractor knows it.

 

The questions to ask your planning team:

"Have we derived the as-built critical path, or just compared two programmes? How have we done that?"

If they cannot answer that clearly, your claim is exposed.

 

 

Best, Radek Makar Director | ViViAD radek@viviad.co.uk

ViViAD is an independent consultancy specialising in Planning, Project Controls, Power BI Reporting, and Construction Claims Support. We work across the UK - typically on NEC contracts in defence, nuclear, renewables, and infrastructure - embedding with project teams to bring structure, clarity, and commercial control. Interim or longer-term, we fit around what you need.