Salisbury Square

Keltbray delivered one of its largest schemes to date at Salisbury Square, the future headquarters for the City of London Police and a landmark £600 million development in the heart of the Square Mile.

The project spans an area four times the size of St Paul’s Cathedral and includes an 18-metre-deep basement for specialist policing facilities. Its scale and complexity required tight coordination and a fully integrated delivery approach.

Keltbray was appointed to deliver the piling, ground engineering, temporary works and logistics, bringing together specialist in-house capabilities to support the complex below-ground infrastructure.

Ground engineering was central to the project’s success. Keltbray installed 434 secant piles, 55 contiguous piles and 26 bearing piles, alongside the excavation of more than 62,000m³ of material to create a new three-storey basement.

The project presented significant geotechnical challenges, including varying ground levels and differing ground pressures adjacent to neighbouring structures. Keltbray developed a hybrid retaining solution combining cantilever and temporary propping systems, enabling deep excavation while maintaining strict ground movement tolerances.

A sophisticated temporary works propping system, designed by Keltbray’s in-house engineering specialists, Wentworth, maintained excavation stability throughout construction.

Building on these below-ground works, Keltbray combined its structural, concrete and logistics capabilities to maintain programme certainty. Key achievements included installing 9,000 tonnes of reinforcement and placing 40,000m³ of concrete, while supporting circular economy principles through the reuse of 785 tonnes of steel.

Scheduled for completion in early 2027, Salisbury Square will play a significant role in the future of policing and public service in the City of London. Keltbray is proud to have contributed to a project that showcases collaborative engineering excellence on a civic scale.

Project outcomes