Principal Consultant – UK

Reporting to: Managing Director, UK

Location: UK (Remote / Hybrid working offered)

We are looking for an experienced and commercially minded Principal Consultant to join our UK team and play a leading role in delivering and growing our consulting business.

This is a senior consulting role for someone who ideally combines deep UK water-sector expertise, exceptional problem-solving capability and strong client leadership. You will be expected not only to deliver excellent analysis and advice, but to shape engagements, challenge clients constructively, develop trusted senior relationships and help Isle identify and win new opportunities.

We are particularly interested in candidates who have developed their expertise within a water or wastewater company, water-related technology provider or contractor, regulator, investor, or leading consultancy/advisory organisation serving the sector.

About Isle

Isle is a UK-headquartered global consultancy. Our work spans technical, strategic, and client partnership advisory focused on navigating challenge and uncertainty across the water value chain, adjacent market sectors, and an all-assets framework.

Our client portfolios and market sectors:

• Water Utilities: Serves as Isle’s primary core market, focusing on asset performance, water resource resilience, innovation capability, trial-to-scale adoption, and delivery assurance.
• Regulation & Policy: Working with regulating bodies (such as Ofwat) and policy makers on independent evidence generation, programme design, sector learning, coordination, and policy interpretation.
• Technology Providers, Investors & Corporates: Providing market entry and validation services, technical and commercial due diligence, customer validation, and trial or deployment support for solutions.
• Industrial Water Users: Focused on water-intensive industries to advise on areas including water consumption, efficiency, and pollution management.

Our consulting Practice Areas:

• Technical Advisory: Delivers physical asset management advisory, technical due diligence, technology roadmaps, resilience diagnostics, trial-to-scale support pathways and operational optimisation.
• Strategic Advisory: Focuses on operating model design, strategic asset-management health planning, regulatory response strategies, collaborative challenge and funding programmes, market and commercial advice, and challenge framing.
• Client Partnerships: Long term Innovation assurance partnerships, retained technology intelligence, portfolio management, and ecosystem orchestration through partnership approaches and peer to peer forums .

Purpose of the Role

As a Principal Consultant, your primary mandate is to LEAD. At this level, you are expected to lead complex assignments, act as a trusted adviser to clients, coach colleagues, and directly drive business growth and technical excellence.

Principal Accountabilities Aligned to Isle’s Six Core Capabilities

All colleagues at Isle build evidence across six core capabilities. As a Principal, your responsibilities will map directly to these areas:

1. Client & Market (Trusted Adviser & Account Leadership)

• Build Strategic Relationships: Act as a trusted adviser to key clients, framing ambiguous challenges and shaping practical solutions.
• Sector Insight: Apply deep technical knowledge, understanding of regulations, and industry drivers to generate market insight and identify emerging needs.

2. Consulting & Technical Excellence (Recognised Authority & Integrity)

• Technical Direction: Provide recognised technical leadership, shape robust methodologies, and review the work of others to ensure scientific rigour and clarity.
• IP & Method Development: Turn expertise into repeatable methods, reusable assets, and external thought leadership that reinforce Isle’s technical authority.

3. Delivery Excellence (Complex Project Leadership)

• Project Ownership: Independently manage complex multidisciplinary client engagements, taking full ownership of delivery, scope, budgets, timelines, risk, and quality.
• Quality Assurance: Challenge and enhance analyses and recommendations, reinforcing high standards in data accuracy, editing, formatting, and visual communication.

4. Commercial Excellence (Proposition & Proposal Leadership)

• Winning Work: Play a leading role in proposal development, pricing, and client presentations, converting commercially strong opportunities into secured revenue.
• Commercial Governance: Scope work accurately, manage project profit margins, and ensure projects are delivered efficiently against agreed commercial parameters.

5. People &Leadership (Coaching & Team Development)

• Achieving Through Others: Coach, delegate, and support junior consultants within projects, creating stretch opportunities and facilitating apprenticeship-style learning.
• Building Capability: Foster a collaborative community of practice, mentoring emerging talent and developing specialists through constructive feedback and peer review.

6. Business Contribution (Internal Initiatives & Collaboration)

• Cross-Matrix Collaboration: Actively promote collaboration across service lines, practice areas, and geographies, drawing on One Isle global capabilities.
• Internal Initiatives: Lead internal business improvement initiatives that enhance delivery tools, methods, or cross-company knowledge sharing.

Essential experience

• Typically 10+ years of relevant professional experience, with substantial experience in strategy, consulting, corporate development, regulation, investment, transformation, infrastructure or the water sector.
• Deep and demonstrable knowledge of the UK water and wastewater sector, with the credibility to engage confidently with senior leaders across water companies, regulators, government, investors, technology providers and the wider supply chain.
• A strong understanding of the strategic, regulatory, commercial and operational dynamics shaping the UK water industry, and the ability to interpret how changes in policy, regulation, technology, investment and customer expectations affect organisations and markets.
• A proven track record of leading complex strategy or advisory engagements from problem definition through to recommendation and, where appropriate, implementation.
• Experience developing and communicating strategic recommendations to senior stakeholders, including Executive teams, Boards, investors, regulators or equivalent audiences.
• Exceptional analytical and problem-solving capability, including the ability to structure ambiguous problems, determine the key questions, interrogate complex datasets and develop robust, evidence-based conclusions.
• Strong commercial acumen, with an ability to understand the economic drivers of a business, assess strategic options and develop commercially credible recommendations.
• Excellent research, synthesis and written communication skills, with the ability to turn large volumes of information and analysis into concise and compelling reports and executive-level presentations.
• Proven client leadership and relationship-management skills, including the ability to build trusted relationships, influence senior stakeholders and manage challenging conversations.
• Experience leading multidisciplinary consulting teams, setting direction,
  managing quality, developing colleagues and creating an environment in which people perform at their best.
• Demonstrable experience of business development, including identifying
  opportunities, developing propositions, shaping client conversations, contributing to proposals and/or winning new work.
• Strong commercial understanding of consulting delivery, including experience with project scoping, pricing, resourcing, financial management and risk management.
• The ability to operate with a high degree of independence, including successfully leading work remotely and taking accountability for outcomes rather than simply completing assigned tasks.

Personal skills

We are looking for a Principal Consultant who can operate as both an exceptional problem solver and a trusted adviser. In particular, you will demonstrate:

• Strategic thinking – able to see the bigger picture, identify the issues that really matter and translate complex market and organisational dynamics into actionable strategy.
• Client leadership – able to build relationships based on credibility and trust, understand the client’s underlying needs and influence decision-makers.
• Commercial judgement – understands what creates value for clients and for Isle Utilities and can balance analytical rigour with pragmatism.
• Influence and communication – able to make complex subjects simple, develop compelling narratives and influence senior audiences without relying on jargon.
• Senior-level facilitation and storytelling – exceptional ability to design and lead engaging workshops, strategy sessions, design sprints and other collaborative forums with senior clients and external stakeholders. Able to create the right environment for challenge and creative thinking, manage different perspectives, navigate difficult discussions and guide groups towards clear decisions and outcomes.
• External presence and communication – highly confident representing Isle Utilities with senior client audiences, industry stakeholders and at external events. Able to develop and deliver compelling, insight-led presentations and narratives that influence audiences, challenge conventional thinking and position Isle
  Utilities as a trusted expert in the sector.
• Leadership – sets a clear direction, creates high standards and brings out the best in colleagues.
• Collaboration and partnership – works effectively with clients, colleagues and external partners and recognises that the best outcomes often come from combining different perspectives and capabilities.
• Resilience and adaptability – comfortable navigating ambiguity, changing priorities and demanding client environments.
• Ownership – takes personal responsibility for client outcomes, team performance and the quality and commercial success of engagements.
• Coaching and development – actively develops more junior colleagues through constructive feedback, mentoring and role modelling.
• Entrepreneurial mindset – looks beyond the immediate project to identify opportunities to create value for clients and develop Isle Utilities’ market position.

Desirable experience

The following would strengthen an application:

• Previous experience in strategy or management consulting, ideally within utilities, infrastructure or the water sector.
• Experience advising or working with water company Executive teams, Boards, Ofwat, the Environment Agency, government departments, investors or major technology/supply-chain organisations.
• Experience of UK water regulatory and strategic processes, including price reviews, AMP cycles, business plans, performance commitments, regulatory strategy or investment planning.
• Experience in one or more of corporate strategy, growth strategy, market entry, commercial strategy, M&A/due diligence, operating model transformation, performance improvement, regulatory strategy or technology strategy.
• Strong understanding of the implications of digitalisation, AI, smart infrastructure, environmental regulation, climate resilience, net zero and emerging water technologies for the UK water sector.
• Experience with financial modelling, market sizing, benchmarking, investment cases, economic analysis or quantitative scenario modelling.
• A track record of winning consulting/advisory work and developing client accounts.
• Established relationships and networks within the UK water sector.
• Experience designing and facilitating senior stakeholder workshops, strategy sessions, design sprints or innovation programmes.
• A relevant degree, postgraduate qualification or professional accreditation. Professional qualifications are welcome but are not essential.

What Isle Commits To

• Clear performance expectations and honest, timely feedback.
• Access to meaningful stretch opportunities to support your progression toward Associate Director.
• Equal recognition for technical specialist authority and strategic business leadership.
• A flexible, supportive, and collaborative working environment.

Application Process

As an equal opportunities employer, we welcome applicants from all sections of the community regardless of age, sex, gender (or gender identity), ethnicity, disability, sexual orientation, and transgender status. If you have a disability and require reasonable adjustments during the application process, please let us know. All appointments are made on merit.

Interested?

To apply, please email [email protected] with your CV and a covering letter, stating your earliest possible starting date and confirming your right to work in the UK.

Closing Date: 21st October 2026. (We review applications on a rolling basis and reserve the right to close the advert early if a suitable candidate is identified.)

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