Diales - Expert Witness services

What Diales - Expert Witness services does

Diales Group plc is a London-headquartered specialist professional services firm, established in 1978 and publicly listed on the AIM market of the London Stock Exchange. The firm provides expert witness and advisory services to the global construction and engineering industry, operating across 14 countries on five continents with a stated headcount of 200+ professionals and multilingual capability in 17+ languages. Its stated mission is to deliver complete solutions throughout the project lifecycle, from dispute avoidance through formal resolution.

The firm operates two principal service lines. Expert Services supply subject-matter experts (all with a minimum of 15 years' practical industry experience) for arbitration, litigation, and alternative dispute resolution, with sub-practices in quantum (financial quantification of claims), delay analysis, project management, adjudicator/arbitrator/mediator appointments, and technical expertise across architecture, civil and structural engineering, MEP, building safety and fire engineering, and energy and environment. Advisory Services provide consultancy across commercial and contract management, planning and programming, dispute resolution, structural design, quantity surveying, BIM, and training. Underlying technical methods include Monte Carlo simulation for probabilistic quantum and risk analysis and computational fluid dynamics for fire and building-safety simulation.

Revenue is generated exclusively through professional services on a custom engagement basis, with pricing determined by project scope, expert seniority, and duration, contracted on multi-year terms through direct enterprise sales to law firms, contractors, developers, and government bodies. The firm markets through a knowledge centre, a quarterly Diales Digest publication, and an international CPD seminar programme (UK NEC-focused seminars plus Middle East FIDIC-focused seminars). Strategic ecosystem positions include wholly-owned DPS (Driver Project Services) for site-based delivery, jointly-controlled EVRA consulting for African coverage, and a January 2025 partnership with Smartsheet in Australia. The parent CEO is Mark Wheeler and Non-Executive Chairman Nicholas Stagg (appointed 1 September 2025).

Name

Diales - Expert Witness services

Legal name

Diales Group plc

Website

https://diales.com

Company type

Public

Founded year

1978

Operating status

Operating

Headcount range

101–250 employees

Ownership category

akta.pro rank

Product category

Construction Expert Witness Services

NAICS

Legal Services (5411), Other Scientific and Technical Consulting Services (54169), Professional, Scientific, and Technical Services (54)

SIC

Services-Legal Services (8111), Services-Engineering Services (8711), Services-Management Consulting Services (8742)

akta.pro primary industry

Litigation Support & Expert Witness Services (BPAHALAG)

akta.pro secondary industry

Litigation & Dispute Resolution (BPAHAAAB)

Keywords

• Construction expert witness
• Quantum expert analysis
• Delay analysis services
• Construction dispute resolution
• Engineering advisory services

Headquarters

HQ city

London

HQ country

United Kingdom

HQ region

Europe

Offices21 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Expert Witness Services: Providing expert witnesses for arbitration, litigation, and alternative dispute resolution proceedings. Experts deliver reports and cross-examination testimony.
2. Advisory Services: Commercial and contract advisory, planning and programming, dispute resolution support, quantity surveying, BIM services, and training for the construction and engineering industry.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

Diales provides expert witness and advisory services to the global construction and engineering industry. Its experts, each with a minimum of 15 years of practical experience, are appointed in arbitration, litigation, mediation, adjudication, and other alternative dispute resolution (ADR) proceedings. The firm also delivers full-lifecycle advisory services including commercial and contract management, planning and programming, dispute resolution support, quantity surveying, BIM services, and technical training to law firms, contractors, developers, and government bodies.

Product overview

Diales is an expert witness and advisory services firm serving the global construction and engineering industry. The company offers two primary service lines: Expert Services (providing subject matter experts for arbitration, litigation, and ADR proceedings) and Advisory Services (consultancy for the full project lifecycle). Expert Services include Quantum, Delay Analysis, Project Management, Technical Expertise across Architecture, Building Safety, Civil Engineering, MEP, and Energy sectors, plus dispute resolution neutrals. Advisory Services cover commercial management, planning, dispute avoidance, structural design, quantity surveying, BIM, and training. The company operates across 5 continents in 14 countries with 200+ staff, working in 17+ languages.

Differentiator

Problem solved

Functional benefit

Brands

• DPS (Driver Project Services): Site-based project services
• EVRA consulting

Products and services

• Expert Witness Services Core expert witness offering providing construction and engineering experts for arbitration, litigation, mediation, adjudication, and ADR proceedings. Each expert has a minimum of 15 years of practical industry experience and is appointed to act as an independent expert on disputes.
• Quantum Expert Services Specialist quantum analysis expertise for construction disputes, including assessment of loss, prolongation costs, disruption, and heads of claim. Used by law firms, contractors, and owners in formal dispute proceedings.
• Delay Analysis Forensic delay analysis services including critical path analysis, windows analysis, time-impact analysis, and as-planned vs. as-built methodologies to determine delay causation on construction projects.
• Project Management Expert Witness Expert witness services covering project management, project controls, and project execution issues on construction and engineering disputes.
• Adjudicators Provision of adjudicators for statutory and contractual adjudication proceedings in the construction industry.
• Arbitrators Provision of arbitrators to act as tribunal members in construction and engineering arbitration proceedings.
• Mediators Provision of mediators for construction and engineering dispute mediation proceedings.
• Technical Expert Witness Services Technical expert witness services for construction, engineering, building safety, fire engineering, and structural design issues on disputes.
• Valuation Services Expert valuation services provided by qualified valuers appointed in dispute proceedings to opine on asset, project, and construction valuations.
• Advisory Services Full-lifecycle advisory services for construction and engineering projects, supporting clients from project concept and tender stages through to dispute avoidance and resolution.
• Commercial and Contract Advisory Advisory services covering contract drafting, contract administration, and commercial management throughout the construction project lifecycle.
• Planning and Programming Advisory Planning and programming advisory including baseline programme reviews, schedule risk analysis, and recovery schedule support.
• Dispute Resolution Advisory Advisory support for parties to construction disputes prior to formal proceedings, including risk assessment, claim preparation, and negotiation strategy.
• Structural Design Services Advisory structural engineering services supporting building design, structural analysis, and remediation work as part of the firm's advisory offering.
• Pre-Contract Advisory Pre-contract advisory covering tender preparation, bid management, and contract strategy during the procurement phase of construction projects.
• Quantity Surveying Quantity surveying services including cost estimation, cost planning, and whole-life costing for construction projects.
• Building Information Modeling (BIM) BIM services spanning 2D-to-7D modeling, BIM management, and BIM execution planning for construction and engineering projects.
• Training Services Technical training services delivered to construction industry professionals covering topics such as delay analysis and dispute resolution.

Named customers2 records

Segments5 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

AI capability6 records

Feature6 records

Partnerships

Three partnerships are on record, tiered core and minor.

• EVRA ConsultingcoreStrategic or Co-development PartnerEVRA are strategic partners in Africa, collaborating on projects across the African continent. Diales works with EVRA to deliver expert witness and advisory services to clients operating in African markets.
• Driver Project ServicescoreStrategic or Co-development PartnerPart of the Driver Group, Driver Project Services provides site-based services complementing Diales expert witness offerings. The two entities work together to provide comprehensive project services.
• Colliers Project LeadersminorStrategic or Co-development PartnerReferenced on Arabic site as a partner organization, providing project leadership services in Middle East markets.

Scale indicators6 records

Recent moves5 records

Expansion highlights5 records

Direct peers

• HKA: HKA is a leading global expert witness and construction disputes consultancy with services spanning delay analysis, quantum, and technical expert testimony. It is the closest direct competitor to Diales in the construction and engineering expert witness niche, with comparable global delivery and similar service taxonomy.
• Berkeley Research Group (BRG): BRG's Construction practice provides expert witness, delay analysis, and quantum services for construction and engineering disputes. Its expert-heavy delivery model and academic credentials position it as a close peer in litigation-support engagements.
• Ankura: Ankura's Construction Disputes practice offers expert witness and advisory services in quantum, delay, and technical testimony for complex construction matters. Its global expert bench and project advisory scale make it a direct competitor in Diales' core service lines.
• Secretariat International: Secretariat is a global expert witness and dispute consulting firm specializing in quantum, delay, and forensic accounting for major construction and energy disputes. It competes head-to-head with Diales on mega-project arbitration and litigation mandates, particularly in energy and infrastructure.
• Driver Group plc: Driver Group is a UK-listed consultancy providing quantity surveying, expert witness, and contract advisory services to the construction industry. It is closely related to Diales (which itself sits within the Driver Group ecosystem via DPS) and overlaps directly on expert witness and quantum mandates.

Broad incumbents

• FTI Consulting: FTI's Construction, Projects & Assets practice provides expert witness, quantum, and delay analysis services alongside broader disputes and forensic offerings. As a large global advisory firm, FTI competes for cross-border mandates with deeper brand recognition but less construction-specific specialization.
• Alvarez & Marsal: A&M's Disputes & Investigations practice includes construction expert witness and quantum services as part of a broader restructuring and disputes portfolio. It competes for large cross-border mandates and brings a strong reputation in distressed and high-stakes situations.
• Kroll (Construction Services): Kroll's Construction Services practice (formerly Duff & Phelps) provides expert witness and disputes advisory for major projects. As part of a broader financial advisory platform, it competes for large cross-border mandates with greater balance-sheet flexibility.

Emerging players

• Mace Group (Consultancy arm): Mace's consultancy business provides project and program advisory for major construction projects, with adjacent dispute and claims support. While not a pure expert witness firm, it increasingly competes for advisory mandates that overlap with Diales' non-expert service lines.

Regional players

• Rider Levett Bucknall (RLB): RLB is a global construction consultancy providing quantity surveying, project management, and advisory services with expert witness capability in select markets. It is comparable on advisory services but is more regionally focused than Diales' dispute-centric model.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/driver-group---diales

Compliance2 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Subsidiaries2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Diales - Expert Witness services