Variations and cost overruns in public works: the expert report in LCSP contracts

In public works, the gap between what was designed and what was actually built produces some of the highest-value claims. Unrecognised variations, unforeseen work items, cost overruns from supervening circumstances or disputes over contract settlement: all require verifiable technical support to succeed against the public authority.

The framework: the Public Sector Contracts Act

The LCSP governs contract modifications, price review and settlement. A solid claim does not argue in the abstract: it contrasts the executed works with the project, the specifications and the contractual rules, and fits each item into the corresponding legal provision. The expert report is the instrument that makes that translation.

What the report documents

The assessment measures and values what was actually built, identifies unforeseen or modified items, analyses the causes —design errors, ground conditions, instructions from the site management— and quantifies the overrun with objective criteria. In contract settlement, it delimits the outstanding items and the disputed penalties.

Why rigour is decisive here

Against a public authority, the burden of technically justifying the claim falls on the contractor. A report documenting each item with measurements, contractual references and calculation is what sustains the claim in the administrative phase and, where applicable, before the administrative courts.

Frequently asked questions

Can you claim a variation already executed but not formalised?
This is a frequent and complex situation. The report documents the reality of the executed works, the factual basis of the claim, without prejudice to the lawyer's legal analysis.

What is the difference between a variation and complementary works?
They fit differently under the LCSP. The expert report provides the technical data to classify each action correctly.

Is it useful for contract settlement?
Yes. Settlement is one of the moments where expert support is most useful to fix the real balance between the parties.