Mary Cross - LLB(Hons), PGDip, DipSurv, ACIArb, Barrister (n/p), MAE


Mary Cross is an Expert Witness specialising in programming and delay and she has undertaken a number of appointments on high value disputes across a range of sectors in the construction industry. She has provided her reports in a number of forums including adjudication and the Court of Session and has particular experience on NEC3/NEC4 disputes.


Clients and instructing solicitors praise her pragmatic approach to forensic delay analysis which focuses on a thorough examination of the facts and understanding of the realistic critical path rather than an undue emphasis on programming software.

Mary also regularly prepares extension of time claims for contractors and reviews claims for employers which gives her an excellent perspective from all sides of the contract.

Recent appointments include:

  • Appointment as delay expert witness by the Employer on a £30M hotel development.  Mary prepared an expert report to ascertain the causes of delay to completion and the contractor's entitlement, if any,  to an extension of time.  This also included consideration of the impact of COVID on the works (JCT DB).
  • Appointment by a contractor to provide an expert report on delay in relation to a £12m hotel refurbishment encompassing Employer delays and the impact of COVID (JCT DB).
  • Appointment by a contractor to provide an expert report on delay in relation to a £5M social housing project focussing particularly on the impact of COVID on the works (JCT).
  • Appointment as delay expert witness on behalf of a contractor in defence of a sub-contractor's claim on a £25M electricity storage project.  The matter proceeded to adjudication where the adjudicator relied heavily on Mary's report in determining the claim in the favour of the contractor (bespoke contract).
  • Appointment as delay expert witness for a Local Authority to determine the contractor's entitlement to increase the Target Price on a £16M leisure facility project (NEC3).
  • Appointment as delay expert witness in an adjudication commenced by the contractor to establish EOT entitlement on a £45M high end residential development in London. The adjudicator determined that the contractor was not liable to pay £12M liquidated damages on the basis of Mary’s report.
  • Appointed as delay expert by Referring Party in an adjudication encompassing a £6M claim on a target cost contract on a processing facility (bespoke form contract).
  • Delay expert witness on £30M delay claim concerning ground conditions and disruption in the area of power generation including support through the adjudication process (FIDIC).
  • Delay expert on a £14M production facility on behalf of the Employer to review the Main Contractor’s applications for extensions of time and the impact of delays on the Employer’s own fit out works (JCT). 
  • Appointment as independent expert by public sector body on a £150M infrastructure scheme. Mary was brought in to review the programme and advise on the contractor’s entitlement to extensions of time. This involved a comprehensive review of all project documentation and an anchor point analysis of all programmes submitted to ascertain the movement of the critical path. (NEC3)
  • Expert Advisor on programme and delay on a large scale road development in the North of England under an NEC3 sub-contract for the construction of 13 bridges encompassing complex issues concerning the Accepted Programme and assessment of the impact of compensation events (NEC3).
  • Delay Expert Witness in £5M claim concerning a Community Heating Project. Mary carried out a detailed programming exercise to ascertain whether there were valid grounds to determine the contract for failure to proceed regularly and diligently with the works (GC/Works 1).

Please contact Mary for a copy of her full CV.