65 Gresham Street

65 Gresham Street

Project Overview

65 Gresham Street represents one of the largest building reuse projects undertaken in the City of London. The redevelopment will deliver approximately 36,800m² of Grade A office, retail, and ancillary space, transforming the existing eight-storey office building with the addition of four new lightweight floors.

Key sustainability achievements include:

• 66% reduction in whole-life carbon
• Operational carbon 12% lower than 2022 GLA benchmarks
• Retention of 70% of the existing structure
• Recycling and reuse of 95% of building materials

This project sets a new precedent for adaptive reuse in the City, combining ambitious engineering with future-proofed sustainability.

The Challenge

Extending an existing building by five storeys is unprecedented in the City of London, where one or two additional floors are typically considered the limit. The bold ambition of this scheme presented significant structural challenges:

• The existing steel frame, lateral stability system, and foundations were not designed for the additional loads.
• Careful strengthening strategies were required to ensure safety and long-term performance.
• The constrained site, located in the busy heart of Gresham Street, demanded meticulous planning of construction sequences and temporary works to minimise disruption.

CBE was appointed to provide the critical construction engineering sequence for the contractor. Our role was central in shaping the architectural vision, ensuring its technical viability, and delivering a safe and efficient build programme.

Approach

Traditionally, a building of this type would have been demolished and rebuilt. However, with growing awareness of the environmental impact of construction, the emphasis has shifted towards redevelopment and reuse. By retaining the majority of the existing structure, the project not only preserves embodied carbon but also enhances return on investment for the building’s owners.

Our Engineering solutions included:

• Detailed analysis of the existing frame to identify strengthening requirements.
• Sequenced construction methodologies to safely integrate new floors with the retained structure.
• Programme analysis to identify sequence changes to optimise the construction programme.
• Temporary works design to support stability during critical phases of the build.
• Coordination with the wider construction team to align structural solutions with sustainability and delivery goals.