Henry Boot Construction Ltd v Alstom Combined Cycles
The case of ‘Henry Boot Construction Ltd. v Alstom Combined Cycles’ [1999] set a precedent that contractor’s rates do not become reasonable or unreasonable by the execution of variations.
The extent to which bill of quantities (BoQ) rates are applicable for valuing variations in the works, is a common cause of conflict on projects, particularly when there are substantial changes in quantities. This can be a particular issue if the rate in question is abnormally high or low due to the fact that an error has been incurred. Contractors argue that abnormally low rates compound losses, while clients point out that abnormally high rates exaggerate contractor profits.
In the case of Henry Boot Construction Ltd. v Alstom Combined Cycles, Henry Boot Construction Ltd. was employed by Alstom to undertake civil engineering works at a power station. Boot quoted a price for temporary sheet piling and this figure was included in the contract. As the works proceeded however, variation instructions affecting the sheet piling were issued.
Boot’s price was found to have been calculated incorrectly, meaning that the additional quantity required by the variation would have given them a large profit. Boot argued that the contract rates must be adhered to whereas Alstom argued that a fair valuation should be made.
At the trial, the judge emphasised the importance of the contract rates, ruling that they were ‘sacrosanct, immutable, and not subject to correction’ on the basis of one party’s dissatisfaction with them. He referred to Clause 55(2) in the relevant ICE Standard Form (6th ed.) contract which stipulated that there should be no rectification of errors, omissions or estimates, and that a mistake in a rate or price bound both parties equally.
The Court of Appeal endorsed the judge’s ruling in 2000, confirming that pricing errors do not allow the parties to adjust the rates.
The rates may however be adjusted where they are used to value variations:
- Where the works are not executed under similar conditions.
- Where the rate is rendered inapplicable by a substantial change in the quantities.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Professional practical experience for Architects in training
The long process to transform the nature of education and professional practical experience in the Architecture profession following recent reports.
A people-first approach to retrofit
Moving away from the destructive paradigm of fabric-first.
International Electrician Day, 10 June 2025
Celebrating the role of electrical engineers from André-Marie Amperè, today and for the future.
New guide for clients launched at Houses of Parliament
'There has never been a more important time for clients to step up and ...ask the right questions'
The impact of recycled slate tiles
Innovation across the decades.
EPC changes for existing buildings
Changes and their context as the new RdSAP methodology comes into use from 15 June.
Skills England publishes Sector skills needs assessments
Priority areas relating to the built environment highlighted and described in brief.
BSRIA HVAC Market Watch - May 2025 Edition
Heat Pump Market Outlook: Policy, Performance & Refrigerant Trends for 2025–2028.
Committing to EDI in construction with CIOB
Built Environment professional bodies deepen commitment to EDI with two new signatories: CIAT and CICES.
Government Grenfell progress report at a glance
Line by line recomendation overview, with links to more details.
An engaging and lively review of his professional life.
Sustainable heating for listed buildings
A problem that needs to be approached intelligently.
50th Golden anniversary ECA Edmundson apprentice award
Deadline for entries has been extended to Friday 27 June, so don't miss out!
CIAT at the London Festival of Architecture
Designing for Everyone: Breaking Barriers in Inclusive Architecture.
Mixed reactions to apprenticeship and skills reform 2025
A 'welcome shift' for some and a 'backwards step' for others.