• Mr. Derek Nelson – Partner & Head of Expert Services, HKA
• Mr. Kelvin Teo - Director, Drew & Napier LLC; Council Member, Society of Construction Law (Singapore)

Derek is a globally recognised authority in construction quantum and delay analysis, and dispute resolution, with over four decades of experience in the construction and engineering industries. A Chartered Quantity Surveyor, Chartered Engineering Surveyor, and Commercial Manager, Derek combines technical expertise, contractual acumen, and strategic insight to complex construction disputes. Currently serving as Partner and Head of Expert Services at HKA, Derek leads the delivery of high-stakes commissions across international markets, coordinating multidisciplinary teams to support clients through litigation, arbitration, adjudication, and other formal dispute resolution processes. His work spans Europe, the Middle East, South America, and Asia, with a focus on delay, disruption, acceleration, prolongation, variation and claims for breach of contract. Derek is a Fellow of the Academy of Experts, the Royal Institution of Chartered Surveyors, and the Chartered Institute of Arbitrators. He is an Accredited and Certified Expert Witness, an Accredited Mediator, and an Accredited Expert Determiner. His credentials include two Master’s degrees in Construction Law and a BSc in Quantity Surveying, alongside the Advanced Professional Award in Expert Witness Evidence. He is frequently appointed as an Independent Expert Witness and Project Neutral, where he blends technical, contractual, and commercial analysis with mediation skills to facilitate fair and efficient dispute resolution.  Derek is a contributing author to the leading industry text Delay and Disruption in Construction Contracts (5th and 6th editions). Recognised annually by Lexology, Who’s Who Legal, as a Thought Leader in Construction Expert Witness services, Derek is praised for his “remarkable clarity of thought and expression,” and his ability to “deliver with clarity and explain difficult issues in understandable terms.” He is widely regarded as one of the foremost experts in quantum and delay analysis for major domestic and international construction projects.

Mr. Kelvin Teo - Director, Drew & Napier LLC; Council Member, Society of Construction Law (Singapore)

Kelvin specialises in resolving complicated infrastructure, energy and resource disputes. Kelvin’s practice focuses on renewable energy projects and sustainability. His sector expertise covers a variety of renewable projects such as solar, offshore wind, hydropower and geothermal projects. Kelvin’s experience also covers nuclear power plants, refineries, mines, railways and expressways; civil works such as buildings, factories, soil remediation and foundation works, and even giant Ferris wheels. His practice includes advising on documentation for such projects. He has advised parties and projects in Singapore, France, Korea, Greater China, Taiwan, Middle East, Mongolia, Taiwan, Italy, Laos, Philippines, Indonesia, Malaysia, Thailand, Vietnam, US, Italy, and India, amongst others.  Kelvin is a Fellow of the Singapore Institute of Arbitrators and sits as an arbitrator, and has recently been recognised as a leading arbitration practitioner in The Legal 500 Arbitration Powerlist: Southeast Asia. He enjoys carrying out advocacy across the entire spectrum of dispute resolution - arbitration, adjudication, mediation, expert determination and evaluation, and litigation, both within and out of Singapore. Kelvin has been recognised by a number of legal directories for his expertise in construction and arbitration. He is also a thought-leader on construction law and arbitration practice issues and sits on a number of professional bodies and panels.

Ashok is a seasoned construction litigator and qualified arbitrator. He has represented a wide spectrum of clients in the construction industry – from developers to main contractors and consultants. Ashok’s experience includes acting as lead counsel at all levels of the Singapore courts, and in arbitrations under the ICC and SIAC rules and adjudications conducted under the Building and Construction Industry Security of Payment Act. Ashok is a Fellow of the Singapore Institute of Arbitrators and is currently serving in the Council of the Singapore chapter of the Society of Construction Law.

Practice Area: Building & Construction 
Training Level: General
Public CPD Point: 1.5