Lead Cost Engineer

At Amentum, we're not just solving problems; we're engineering the future. Our team is driven by an unyielding commitment to innovation, integrity, and collaboration, tackling some of the most significant challenges in science, security, and sustainability. If you're passionate about making a real impact and want to be part of a community that values ethical excellence, this is the place where your ambition can thrive.

Here, we believe that success comes from continuously pushing boundaries and working together to deliver on our promises. We embrace challenges with confidence and are dedicated to creating a secure and vibrant future for all.

We’ll inspire and empower you to deliver your best work so you can evolve, grow and succeed – today and into tomorrow. We offer an exciting range of opportunities to develop your career within a supportive team who always strive to do the right thing for our people, clients and communities.

People are our greatest asset, and we offer a competitive package to retain and attract the best talent.

In addition to the benefits you’d expect, UK employees also receive free single medical cover and digital GP service, family-friendly benefits such as enhanced parental leave pay and free membership of employee assistance and parental programmes, plus reimbursement towards relevant professional development and memberships.

Work-life balance and flexibility is a key focus area for us. We’re happy to discuss hybrid, part-time and flexible working hours, patterns and locations to suit you and our business.

Amentum is a key Lot 1 delivery partner within the Decommissioning and Nuclear Waste Partners (DNWP) Framework, a major Sellafield programme worth up to £ billion and running for up to 15 years. The framework is focused on safely accelerating decommissioning, remediation and high‑hazard risk reduction across one of the most complex nuclear sites in the world.

Our nuclear team supports the front‑end design, engineering, technical leadership and delivery expertise required across the DNWP portfolio. We are looking for individuals with high‑value expertise from across regulated and comparable sectors to who can work collaboratively, embrace new challenges and contribute to the mission of safely and efficiently delivering Sellafield’s decommissioning and nuclear waste objectives.

About the Opportunity

As a Lead Cost Engineer you will be responsible for coordinating the project's financial and budget activities to maximize earnings and increase efficiency. Monitor projects to manage scope and deliverables.

May act as a point of contact for the client. Identifies and manages project risks.

You will be reporting to Project Controls Manager and working alongside Project Managers and Engineers, Commercial Team including QS and Commercial Managers, Estimating Team and Sales Team.

Responsibilities in this role include managing project budgets, forecasting costs, controlling expenditures, and providing financial insights through detailed analysis, reporting, and stakeholder collaboration, requiring strong technical skills in cost estimation, project management software, and leadership to mentor teams and drive cost optimization for large projects. Key duties include budget development, variance analysis, financial reporting, risk assessment, change order review, and ensuring compliance with financial standards across the project lifecycle, from conception to close-out.

Employee will be expected to contribute to the delivery of social value in line with the DNWP framework, supporting positive outcomes for local communities. Voluntary engagement is supported, with up to 16 hours per full‑time equivalent allocated.

Key Responsibilities

• Lead team of Project Controls Professionals to deliver larger projects / Frameworks.

• Expert in field of knowledge.

• Cost Estimation & Budgeting: Develop comprehensive cost estimates, budgets, and financial forecasts for complex projects, ensuring accuracy and alignment with business objectives.

• Cost Control & Monitoring: Track expenditures, analyse variances, and implement corrective actions to keep projects within budget

• Financial reviews and reporting: Prepare and present detailed financial reports (, EAC, Forecast to Go, VOWD) to project teams, management, and clients.

• Stakeholder Collaboration: Work closely with project managers, engineers, procurement, and commercial teams to provide financial insights and support decision-making.

• Risk Management: Identify cost risks and opportunities, providing recommendations for cost optimization and savings.

• Process Improvement: Contribute to the development and enhancement of cost control procedures, tools, and systems.

• Project set up, close out and reconciliations

• Revenue, GM and aged debt monitoring

• Ensuring corporate systems are up to date and an accurate reflection of the project

• Contribute to progress meetings, as required, in support of the Project Manager.

• Regular interfacing and integration with the project controls team to maintain an aligned financial position with the Project Plan.

• Monitoring key performance indicators as necessary.

• Act as Mentor and provide guidance to less experienced Cost Engineers.

• Takes a broad perspective to identify innovative solutions; identifies applications of functional knowledge and existing methodologies to complex problems.

Essential Skills & Experience

• Holds Professional qualification in Project Management, Project Controls, Quantity Surveying, Engineering or equivalent experience

• Proven significant experience in managing and delivering cost engineering services on major projects or across complex multiple-project programmes

• Previous experience of working under various Contract Types with an understanding of their complexities

• Strong background in tracking expenditures, analysing variances, and implementing corrective actions to keep projects within budget

• Proven experience preparing and presenting detailed financial reports to project teams, management, and clients.

• Demonstrable experience in risk and opportunity management relative to the cost engineering role

• Previous experience managing a team

• Ability to mentor and support team members, acting as a trusted advisor and subject matter expert when required.

• Excellent communication, stakeholder management, and relationship-building skills.

Our Culture

Our values are built on a strong foundation of safety, integrity, and respect for every individual. People are at the heart of our mission, and we believe in supporting one another through a culture of care and collaboration.

We strive to create a workplace where everyone feels they belong and can thrive. Supporting mental wellbeing and fostering a sense of connection are essential to how we work.

When we embrace different perspectives and work together, we become more innovative, more agile, and more successful.

We partner with VERCIDA, for greater online accessibility please visit to view and access our roles. As a Disability Confident employer, we will interview all disabled applicants who meet the minimum criteria for a vacancy. We welcome applications from candidates who are seeking flexible working and from those who may not meet all the listed requirements for a role.

If you require further support or reasonable adjustments with regards to the recruitment process (for example, you require the application form in a different format), please contact