Job Description

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Commercial Manager
Sizewell C

Contract Type: Permanent - Office-based with hybrid flexibility (typically 3 days p/w in the office)
Working Pattern: Full time
Closing Date: Sunday 16th August 2026
Location: London
Salary: Circa £66,000 depending on experience
Bonus: 5% annual incentive
Pension: Up to 7.5% employee contribution / 15% employer contribution
Holiday: 28 days plus bank holidays
Benefits: Flexible benefits

Impact:

We're looking for an experienced commercial professional with a strong track record in major infrastructure, engineering, or construction projects. Ideally, you'll have experience within heavy civils and knowledge of NEC3/NEC4 contracts. You'll be confident managing commercial activities across allocated contracts or work packages, supporting project teams, assessing change, managing risk, and helping to deliver successful commercial outcomes.

Your role will be to:

Manage the commercial administration of allocated contracts and work packages within major infrastructure projects.
Administer NEC3 and NEC4 contracts, ensuring compliance with contractual obligations and project procedures.
Prepare and manage commercial documentation, including early warning notices, compensation events, payment assessments, and programme submissions.
Review and evaluate quotations, subcontractor submissions, and change proposals.
Support the preparation of position papers, commercial reports, forecasts, and cost analysis.
Work collaboratively with project, engineering, procurement, and supply chain teams to ensure effective commercial delivery.
Identify, manage, and mitigate commercial risks and opportunities.
Build strong relationships with internal and external stakeholders, providing clear commercial advice and support.
Contribute to cost control, change management, and commercial governance processes.
Support senior commercial leadership in achieving project and business objectives.

What You'll Bring

Proven experience working within commercial management on major construction, infrastructure, engineering, or heavy civils projects.
Good working knowledge of NEC3 and/or NEC4 contracts.
Strong commercial awareness, contract management, and negotiation skills.
Experience preparing and administering compensation events, early warnings, and payment applications.
Ability to analyse commercial data and provide clear recommendations.
Strong stakeholder management and communication skills.
Knowledge of UK contract law and procurement practices.
Degree-qualified or equivalent industry experience.
Professional membership (RICS, ICES, CIOB, CIPS) desirable or working towards chartership

Why Join Us

A major infrastructure project with national impact 
Hybrid working with flexibility built in 
Competitive salary, bonus and benefits 
Clear progression and development opportunities 
Supportive, collaborative team environment  

Behavioural Competences

Humility

Recognise the value brought from different cultures and experiences
Be open to other’s points of view and ideas, be willing to debate and to compromise

Positivity

Positively challenge poor quality and performance
Identify solutions at the lowest possible level
Encourage tier 1s and others to bring new ideas forward

Respect

Value the rules and environment in which we operate
Give and receive feedback with respect
Embrace and engage with new people and ideas

Solidarity

One team, working closely together and helping each other
Empowered teams always looking forward.
Shared responsibility for delivery the project outcomes

Clarity

Communicate clearly and consistently
Promote collaboration and team alignment
Clearer and faster decision making
Drive simplification at all levels

If this sounds like the next step in your career, we’d love to hear from you. Apply today.

For this role you must have evidence of right to work in the UK. As a project, we do not discriminate on the grounds of age, gender, race, colour, religion, disability or sexual orientation, and we welcome applications from all sections of the community.