Sizewell C Opens £250 Million Tender For Bulk Earthworks Contract

Sizewell C Ltd has issued a tender for a two-year bulk earthworks contract worth up to £250 million, marking a key stage in preparations for the twin-reactor nuclear power plant on the Suffolk coast. The works, scheduled to begin in January 2027, will form the foundation phase for the £38 billion development.

The contract involves the removal of approximately 3.3 million cubic metres of soil and sand, including crag and peat, from the main construction area. The material will be moved via a segregated haul route to temporary storage and disposal zones within the wider construction site. Operations will rely on heavy-duty 45-tonne dump trucks to manage the constant movement of excavated material.

Alongside excavation, the contractor will be responsible for testing, sorting, and compacting suitable materials for reuse, while shaping disposal areas in line with the site’s engineering and environmental standards. Backfilling work will proceed in parallel to excavation to allow early foundation construction for Units 1 and 2, helping to streamline the nuclear build programme.

The earthworks form part of the project’s broader Main Works Earthworks Programme, delivered in coordination with the Civil Works Alliance, which includes Balfour Beatty, Laing O’Rourke, and Bouygues Travaux Publics. The alliance will oversee access management and transport operations across the site during the excavation phase.

Bryan Jenkinson, Procurement Lead at Sizewell C, said the launch of the tender “signals a transition from enabling works to large-scale site preparation,” adding that it will “create the groundwork for the main civil engineering phase of the project.”

Preliminary activities have already been completed by Blackwell Earthmoving and Jackson Civil Engineering, which delivered site compounds and access roads to support the next phase of works.

The bulk dig contract will run from 4 January 2027 to 8 December 2028, with tenders closing at 5pm on 31 October 2025 through the CompeteFor portal.

Sizewell C, being developed by EDF and its partners, represents the UK’s next major nuclear investment following the government’s final investment decision earlier this year. Once operational, it is expected to provide low-carbon electricity to six million homes, contributing to the UK’s long-term energy security and net-zero ambitions.