Project Update – July 2025

Welcome to the July round up of activity at Sizewell C. Sizewell C has secured its Final Investment Decision (FID), giving the green light to the nuclear plant.

We have announced the new shareholders of the project, with the government the largest shareholder, alongside EDF, Centrica, La Caisse and Amber Infrastructure. For more information please click here to read our press release.

Following FID, we announced the location and designs of the College on the Coast. This post-16 education facility will be located on the eastern edge of Leiston on King George’s Avenue, opposite the Sizewell C Ancillary Construction Area.  The college will include an apprentice hub and will have space for 150 students, 20 full-time staff and drop in space for 50 apprentices.  For further information please click here.

We also launched the East Suffolk Trust (EaST) which is a new grant-giving charity, set up to enhance biodiversity and restore landscapes in east Suffolk and the wider county. This includes at least £78 million over the next 70 years, with the aim to make East Suffolk the most ecologically diverse and resilient area in England. To find out more please read our press release.

Finally, a reminder that we give advance notice of our wide and abnormal load movements on the Sizewell C Works Tracker. This is updated weekly to help local road users plan their journeys.

Main Development Site

Work has started to build the foundations of the water desalination plant and concrete batching plant on the Temporary Construction Area. We have also started preparing compounds for installation of the water shaft which will bring sea water to the desalination plant.

The foundations for the campus have started to be poured. This includes the amenity building and four accommodation blocks.

The Civil Works Alliance continues to prepare for the installation of the first bridge over the Site of Special Scientific Interest.

On the Main Construction Area work continues to prepare the ground and site for construction.

Ahead of the required bulk excavation works we have installed the first section of the plastic cut-off wall. This 55-metre-deep wall is constructed in panels and is located on the perimeter of the Main Construction Area. Once complete, the 3,000m long wall will enable dewatering and bulk excavation to take place.

We will start laying foundations for Primary Network Survey stations during August. There will be 18 stations in total across the Main Development Site to support setting out of structures.

On the Ancillary Construction Area off King George’s Avenue in Leiston we are progressing well with earthworks. We have taken delivery of ballast and pre-assembled straight track sections ready for the construction of the railhead. The required switch and control units, also known as points, are already constructed and in storage off-site ready to be delivered when needed.

Sizewell Beach and Harbour Area

Construction of the northern section of the temporary sea defence has started with the first sheet piles being installed. The works will take place within the Sizewell C fence line, with the public footpath remaining open.

Work will soon commence on installing a temporary outfall on the beach. This work will all take place within a fenced compound.

To ensure progress of the temporary sea defence it will be necessary to work every other weekend in August including 9-10 August and 23-24 August. Further details of the works can be found on the Sizewell C Works Tracker.

Marine Harbour

Our obligations as a Statutory Harbour Authority require us to publish General Directions which detail the restrictions that apply to vessels operating in the harbour area. These have now been consulted on and implemented, including the harbour area boundary and how the public will be informed of activities in the harbour. Notices and signs will be installed at the Sizewell Beach car park to support this.

Several marine surveys are taking place in the harbour during August, and towards the end of this year construction works will begin in earnest for both the Beach Landing Facility and the Marine Bulk Import Facility. This will involve works on the beach and more vessels, such as jack-up barges, operating within the harbour area. We will give more details of these works closer to the time. Further information on marine and harbour works can be found on our Works Tracker.

In and around Leiston

We have started on the new junction of Lover’s Lane and Abbey Road as part of the realignment work to allow us to install a new level crossing for our Green Rail Route. Three-way traffic lights will be implemented at the junction in order facilitate advanced works for utility installation and the Lover’s Lane temporary road alignment.

We are also continuing to prepare the site of the plaza roundabout to get it ready for construction.

During August, Essex and Suffolk Water will be working at night on weekends in the B1122 Abbey Road area as part of the works to create the Green Rail Route. These works are taking place in the field, away from the carriageway, and are not expected to cause any adverse noise disturbance.

Community Road Improvements

We have installed average speed cameras along the B1122 and B1125 to enhance road safety in the new 30mph speed limit. On the B1122 the average speed cameras are in operation between Yoxford and Leiston, and the B1125 speed cameras are between the B1122 junction and Westleton. The speed limits are now enforceable with legal penalties which are enforced by Suffolk Constabulary.  

From the 11 August permanent 30mph signs along B1122 will begin to be installed.

The upgrade work to the layby on the northern carriageway of the A12 near to the B1078 will begin in mid-August. This work will help us to manage our Abnormal Indivisible Loads which are escorted by the police. There will be a lane closure along the dual carriageway section of the A12 during this time.

Off-Site Infrastructure

Two Village Bypass and Friday Street Roundabout

We have installed welfare facilities for our team at the Friday Street Roundabout compound ahead of main works starting later in the summer. We have now completed all vegetation removal at this site including the large oak tree, with the wood being used in local community projects. Along the Two Village Bypass all the site accesses have now been established, and construction will begin once our archaeological surveys are complete.

A 30mph speed limit has been implemented along the A12 for the duration of the works around the Friday Street site. This is to ensure the safety our the public and our workforce during construction. Further traffic calming measures have also been installed including lane management cones and lining.  As work progresses, further traffic management and some smaller road closures will be required, which we will publish once timelines are confirmed.

Sizewell Link Road

All the site accesses required for the construction of the Sizewell Link Road have now been completed. Our contractor, Galliford Try, will be undertaking the construction of the road and will start setting up their compounds, establishing haul roads and moving equipment from the week commencing 11 August.

We are working on details of required road closures that surround the Sizewell Link Road site and will share dates and details in due course, Pretty Road will close this Autumn in order to build a bridge that will cross the Sizewell Link Road.

We have recently resurfaced Town Hall Farm Lane to improve the road access for residents and to our compounds. We continue to prepare the western end of the road alongside the A12 which will include a haul road. We are working closely with the solar farm project adjacent to our site to understand logistics and HGV movements.

Yoxford Roundabout

Construction of Yoxford Roundabout began in July with site establishment and earthworks to bring the level of the site close to the current level of the A12. The roundabout will be completed in  mid-2026, with most of the work taking place offline before the final connections to the A12 are made. A 30mph speed limit along the A12 is in place to ensure the safety of the public and our workforce.

Park and Rides

With archaeology now completed, site preparation, including construction of compounds and welfare facilities, and ecology mitigation continues at both our Northern Park and Ride in Darsham and Southern Park and Ride in Wickham Market.

Construction of the roundabout next to the A12 and Willow Marsh Lane at the Northern Park and Ride has started. To improve safety for all road users a 30mph speed limit on the A12 is planned between the A144 and the Darsham Level crossing supplemented by traffic management schemes which are under development.

Orwell Logistics Park and Freight Management Facility

The Freight Management Facility, located within Orwell Logistics Park, is now fully operational.

We continue to expand the office space at Orwell Logistics Park to ensure a good spread of workers across the region and taking the pressure off Leiston.  70 more workers are moving to the site this summer, a further 200 desks will be made available by the end of the year.

Rail Works

The new compound at Leiston Airfield is now complete. This will allow our teams delivering rail improvements to move from the current Buckleswood Road compound, which will then only be used for materials management and storage.

Track renewal works have been taking place on the Leiston Branch Line. These works are to install new track with a New Track Construction machine which replaces the existing rail sleepers and track. This is a key piece of plant as it is both safer and quicker than other methodologies. For further details please visit our Works Tracker.

Balfour Beatty will be carrying out vegetation clearance on the Valley Road rail bridge between Monday 4 August and Thursday 7 August.

 Forum Schedule
Our forums and working groups are a way for local people to hear about key issues related to the construction of Sizewell C. All forums run from 18:30 to 20:30 (arrival from 18:00).

All meeting papers and presentations can be accessed on our website Community Forums - Sizewell C. If you have any questions or would like further information, please do not hesitate to contact us. We are available in person at the Information Office on the High Street in Leiston (Monday to Friday, 09:30 to 17:00), via the 24-hour helpline on 0800 197 6102 or by email info@sizewellc.com.