Derek Pye

Practice Summary

Derek is a practising Barrister, Chartered Arbitrator, Adjudicator Mediator and Expert Determiner as well as a Chartered Quantity Surveyor.

His career in the construction industry has spanned over thirty years working for contracting and consultancy organisations in the UK and overseas including the USA, Canada, Germany, Switzerland, Belgium, Italy and in Saudi Arabia with French, Italian and Korean contractors.

Derek’s early experience in the architectural field included eight years spent in the planning, design and on and off-site supervision of major housing schemes.  This was followed by a career move into quantity surveying, firstly in housing, but later and more predominantly into the industrial and commercial sectors.

His contracting experience with major UK and French international building and civil engineering companies was broad and he advised UK design and build contractors and specialist structural steelwork companies, on contracts with values in excess of £1,500 million.

Derek’s consultancy experience included the management and resolution of construction and civil and mechanical engineering disputes by negotiation, mediation, conciliation, adjudication, litigation and arbitration, with disputed amounts in excess of £40 million.

Derek has prepared Expert Reports on behalf of clients in contemplation of litigation and arbitration.  He has acted as an expert witness in construction disputes on multi-million pound quantum matters and planning inquiries and been subject to cross-examination by Counsel in arbitration and the TCC.

Derek’s broad based construction experience adds value for Solicitor and lay clients in that he is able to quickly assess the quality of the evidence of both factual and expert witnesses at an early stage of the dispute.  His experience means that he is an accomplished strategist in all aspects of construction disputes.


Derek has been practising as an arbitrator for 25 years and has published approximately 100 Awards.  Recent appointments include:-

  • SGL Carbon Fibers Ltd v RBG Ltd [2012] CSOH 19.
  • £7m claim on a hotel at Heathrow
  • Extension of time and £3m loss and expense and variations claim and £1m counterclaim on a commercial development in London.


Derek has been appointed as Adjudicator and published Decisions on over 150 adjudications with values extending to several million pounds.  Derek also chairs RICS panels assessing adjudicators to become members of the RICS President’s panel of adjudicators.  Recent adjudicator Appointments include:-

  • University loss and expense claim for £1.25m in Cambridge
  • Demolition contract at a university campus in London
  • £4m dispute on a commercial building contract
  • Mechanical services dispute on the O2 Arena
  • Electrical contract dispute on the Channel Tunnel Rail Link


Derek is an accredited mediator of the CIArb and accepts appointment as mediator in construction, engineering and general commercial disputes. Derek is a member of the Association of Northern Mediators. Recent mediation appointments include:-

  • Institution appointed mediator in three sports centre disputes
  • Party appointed mediator in a multi-storey car park dispute
  • Court appointed mediator in a residential construction dispute


Derek has appeared as advocate in:-

  • An $8m breach of covenant/warranty and fraud claim in arbitration in the USA involving international trade country of origin issues
  • A dispute in the UK over the interpretation of the overage provisions of a £5m development agreement.
  • An aviation related criminal trial.

Derek was also involved with Counsel in the successful appeal against an arbitrator’s award in the case of:- Newfield Construction Ltd v Tomlinson & Ano [2004] All ER (D) 280 Nov

Expert Determiner

Derek’s practice includes an increasing number of Expert Determinations particularly in the land/property development field. Recent disputes have included the awarding of a £14m construction contract and a multi-million pound overage provision.

Expert Witness

Derek has acted as witness of opinion in various cases in litigation and arbitration on matters of quantum and project planning. Reported Cases include:-

  • Motherwell Bridge Construction Limited (Trading as Motherwell Storage Tanks v Micafil Vakuumtechnik, Micafil; 81 Con. L.R. 44; [2002] All ER (D) 159 (Mar)
  • Ruttle Plant Hire Ltd v Secretary of State for the Environment, Food and Rural Affairs [2004] EWHC 2152 (TCC), 104 ConLR 110, [2005] All ER (D) 182 (Dec)


Derek is a multi-engine, instrument rated, commercial pilot.

He was the consultant construction expert in the BBC third series of Rogue Traders and made personal television appearances in two of the programmes in the series.

Areas of Expertise

  • Construction
  • Professional Negligence
  • Aviation Law

Reported Cases

  • Adjudicator in Allied P&L Ltd v Paradigm Housing Group Ltd [2009] EWHC 2890 (TCC) (17 November 2009); [2009] 47 EG 132, [2010] BLR 59
  • Adjudicator in OSC Building Services Ltd v Interior Dimensions Contracts Ltd [2009] EWHC 248 (TCC) (08 January 2009); [2009] CILL 2688, [2009]
  • Expert on behalf of Motherwell Bridge Ltd in Motherwell Bridge Construction Limited (Trading as Motherwell Storage Tanks v Micafil Vakuumtechnik, Micafil; 81 Con. L.R. 44; [2002] All ER (D) 159 (Mar)

Notable Cases

  • [Aviation Law] CAA v Pemberton (unreported)
    Acted as defence counsel in unsuccessful criminal prosecution of a commercial pilot under the Air Navigation Order 2005 in an alleged low flying incident over Manchester City Football Club’s Eastlands Stadium.


  • “Abatement, Set-off and Counterclaim- the art of how not to pay somebody” – University of Central Lancashire; MSc in Construction Law and Dispute Resolution.
  • “What is Evidence?” - University of Central Lancashire; MSc in Construction Law and Dispute Resolution.
  • “Managing Payment to Avoid Disputes” – RICS Avoiding and Resolving Disputes in Engineering and Construction Contracts Conference, London.
  • “Resolving Disputes in Construction; a Review of Recent Developments and a Perspective on Effective Dispute Resolution” – SCL/RICS/University of Manchester Conference.

Download CV

  • Call: 2008


  • Chartered Arbitrator (since 1998)

Professional Associations

  • Fellow of the Royal Institution of Chartered SurveyorsFellow of the Chartered Institute of ArbitratorsMember of the Academy of ExpertsCommercial Pilot (CPL/IR)


  • LLB(Hons), FRICS, FCIArb, MAE, Barrister at Law.

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Derek Pye
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T: 0113 245 5438 (DDI)
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Office address:
10 Park Square

T: 0113 245 5438
F: 0113 242 3515