“Sizewell C represents a critical step in securing the U.K.’s clean energy future,” Richard Sanderson, Jacobs executive vice president for Europe, said in a statement. Jacobs will support development of delivery systems and governance needed to enable “safe, efficient and integrated delivery” of the project, he said.

The selection follows the U.K. government’s final investment decision on Sizewell C in July 2025, which confirmed an estimated capital cost of about $51 billion (in 2024 prices) and authorized use of a regulated asset base (RAB) financing model, according to documents published by the Department for Energy Security and Net Zero and Sizewell C Ltd.

RAB Financing Raises Stakes for Delivery Oversight

Under the RAB model, certain construction costs can be recovered from electricity consumers during the build period, a structure intended to reduce financing costs but one that also subjects the project to formal economic regulation.

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Government and regulatory filings tied to Sizewell C approval and reviewed by ENR establish allowable capital spend limits, cost-reporting requirements and intervention thresholds if projected overruns emerge during construction.

Project documentation released as part of the regulatory process shows that Sizewell C’s delivery model incorporates independent technical and delivery assurance functions designed to support government and regulator oversight of cost, schedule and risk management.

Those mechanisms were developed in response to cost growth and schedule delays on previous U.K. nuclear projects, including Hinkley Point C, according to government statements and National Audit Office reporting on the nuclear new-build program.

That governance structure sits alongside alliance-based contracting already in place for major construction packages. Sizewell C has previously named a civil works alliance led by U.K. contractors Balfour Beatty, Laing O’Rourke and Bouygues Travaux Publics, a unit of France-based Bouygues Group, to deliver the project’s main civil engineering works, according to project announcements.

Alliance contracting is intended to encourage collaboration and early risk sharing, but it also places greater emphasis on independent assurance and change-control discipline as construction progresses.

Jacobs’ role, as described by the company, is separate from those construction delivery responsibilities and is focused on program integration, governance and technical support rather than direct execution.

Sizewell C and Jacobs have not publicly detailed how that role interfaces day to day with alliance contractors or with Electricite de France (EDF), the country's state-owned utility firm, which remains a shareholder and technical reference point for the project.

The project is being developed as a near replica of the U.K.'s Hinkley Point C, the twin-reactor nuclear plant under construction in England's County Somerset—a strategy intended to reduce delivery risk by standardizing design and construction approaches, according to Sizewell C and government project materials.

For contractors and suppliers, that governance structure has practical implications on the jobsite: delivery under the regulated asset base framework places greater emphasis on documented cost forecasting, schedule justification and risk mitigation, with independent verification embedded in reporting cycles.

Contractors should expect tighter change-control processes, as well as enhanced schedule scrutiny and more formal interfaces between delivery teams, technical assurance functions and the project owner as construction progresses.

Once it is operational in the mid-2030s, Sizewell C is expected to generate enough low-carbon electricity to power about six million homes for at least 60 years, according to U.K. government and project company estimates. The project is a central element of the government’s strategy to replace an aging nuclear power fleet, which is expected to retire in the early 2030s.

Construction is underway at the Suffolk site following completion of early works. Sizewell C says the project would support about 10,000 jobs at peak construction, with tens of thousands more across the supply chain, and create roughly 1,500 apprenticeships. The company added that about 70% of construction spending is expected to go to U.K.-based suppliers.

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Jacobs, which said it brings more than six decades of experience in the nuclear sector, did not disclose the value of its contracted role or provide details on how it interfaces with EDF or with Sizewell C’s internal delivery team.

In the U.K., the company has supported projects including Hinkley Point C and the Sellafield nuclear waste cleanup site program. ENR has previously reported that Sizewell C is the first majority British-owned nuclear power project to move forward in decades.

With financing secured and construction activity increasing, attention now shifts to execution and delivery performance, making the effectiveness of project governance and assurance structures as consequential as the reactors themselves.