UK government oversight of Sizewell C enters a new phase with Mott MacDonald’s technical advisory appointment.
The Department for Energy Security and Net Zero (DESNZ) has appointed Mott MacDonald to deliver technical advisory services supporting government oversight of the Sizewell C nuclear power plant on the Suffolk coast. The appointment strengthens the UK Government’s capability to oversee one of the most significant infrastructure projects within the national clean energy programme.
Mott MacDonald will provide technical advice, guidance and assurance to enable DESNZ to fulfil its responsibilities as both Shareholder and Policy Sponsor during the construction phase. The role supports informed decision-making across engineering, delivery assurance, risk management and digital construction governance for the Sizewell C nuclear project.
Supporting digital construction and project complexity
The technical advisory services will underpin government oversight by addressing the complexity associated with large-scale nuclear construction. This includes assurance of construction methodologies, systems integration, data-led project controls and alignment with regulatory and safety requirements.
Through digital construction processes, structured information management and technical assurance, the services are intended to support predictable delivery outcomes while maintaining transparency across cost, schedule and performance. This approach reflects the growing importance of digital construction oversight in complex energy infrastructure programmes.
Sizewell C and the UK’s clean energy strategy
The government announced the Final Investment Decision for Sizewell C in July 2025, marking the first nuclear project to reach this milestone in nearly a decade. Once operational, Sizewell C is expected to generate around 7% of the UK’s electricity supply and reduce carbon emissions by an estimated 9 million tonnes of CO₂ annually.
The project aligns with wider government efforts to remove barriers across planning, grid infrastructure and supply chains, supporting accelerated deployment of clean energy technologies and reinforcing the UK’s energy security.
Industry perspective on the appointment
Commenting on the contract award, Claudio Tassistro, managing director of energy, UK and Europe, at Mott MacDonald, said: “This appointment builds on our long-standing relationship with DESNZ, where we’ve contributed to the delivery of critically important programmes addressing the challenges of the transition to a low-carbon economy. Sizewell C stands as a key initiative for the UK, supporting both the achievement of net zero targets and the nation’s energy security. We’re proud to play a role in this significant project.”
Through strengthened technical oversight, digital construction expertise and policy alignment, Sizewell C demonstrates how government and industry can jointly deliver secure, low-carbon nuclear infrastructure at national scale.
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