IN Brief:
- Multiplex has been confirmed as main contractor for the £300m redevelopment of 99 City Road in London.
- The retrofit and extension will create a 36-storey, 475,000 sq ft office building with 6MVA of power infrastructure and 45,000 sq ft of amenities.
- Main construction is due to begin within weeks, with practical completion targeted for 2030.
Multiplex has been confirmed as main contractor for the £300m redevelopment of 99 City Road in London, with main construction works due to begin within weeks.
Endurance Land is managing the project for owner Nan Fung Group, transforming an outdated 1990s office building at the meeting point of Old Street and the City into a 36-storey commercial tower. The completed scheme is planned to provide 475,000 sq ft of floorspace, with practical completion targeted for 2030.
Multiplex has already worked on the scheme under a Pre-Construction Services Agreement, giving the contractor early involvement in buildability, logistics, design development, procurement, and programme planning before the main contract was signed.
The wider project team includes Kohn Pedersen Fox Associates as architect, AKT II as structural engineer, Arup on MEP and sustainability, Arcadis as cost consultant, and FMDC as façade consultant.
Rather than demolishing the existing building completely, the project is based on retrofit and extension, with Endurance Land pursuing a retain-first strategy that preserves most of the existing structure. That approach reduces the volume of primary structure being replaced but places greater emphasis on surveys, strengthening, demolition sequencing, temporary works, and interfaces between retained and new construction.
Existing column grids, slab capacities, foundations, cores, and service zones establish constraints that would not apply on a cleared site. Structural changes and new loads must be coordinated around those fixed elements before the project moves into façade, MEP, fit-out, and commissioning work.
Richard Rixson, director at Endurance Land, said: “That complete alignment gives us, and our future occupiers, total confidence as we transition into active construction on a flagship project that will define London for decades to come.”
The occupier specification includes 6MVA of power infrastructure and 45,000 sq ft of amenity space. Plans also provide event, wellness, and conference facilities, private terraces, collaborative workspace, end-of-trip facilities, and 574 cycle spaces.
The project is targeting EPC A, BREEAM Outstanding, NABERS 5, WELL Gold, and SmartScore and WiredScore Platinum ratings. Delivering those standards will depend on façade performance, building-services installation, controls, metering, commissioning, and post-handover operation rather than certification targets alone.
Power capacity is a notable part of the brief for a building aimed partly at technology and innovation-led occupiers. Higher electrical loads, resilient connectivity, cooling demand, smart-building systems, and dense digital equipment place additional pressure on risers, plant areas, distribution routes, heat rejection, and maintainability, particularly where much of the original structure is being retained.
The project sits within a broader London pipeline of commercial buildings being retained and upgraded rather than demolished. Railpen’s 12 Smithfield Street scheme is also retaining an existing structure while pursuing higher energy and workplace standards, although 99 City Road is larger and carries substantially greater vertical and structural intervention.
Site logistics will remain constrained throughout the build. Old Street and the surrounding City fringe provide limited laydown space, while deliveries, crane operations, workforce access, removals, and neighbour management must be coordinated around an active commercial district.
The retained-building strategy also creates a higher dependence on survey information as construction progresses. Opening-up works may expose local strengthening needs, undocumented alterations, or service routes that differ from record drawings, so design decisions must remain responsive without allowing changes to destabilise the programme.
Façade replacement and extension works will need to follow that structural information closely. New envelope sections must connect to retained slabs and columns while meeting current thermal, weathering, acoustic, fire, and maintenance requirements, and temporary weather protection will be needed as old and new elements are exchanged.
Early contractor involvement gives the team a chance to resolve structural sequencing, façade strategy, temporary works, MEP routes, and long-lead procurement before the most expensive packages are fixed. On a multi-year retrofit, that preparation can reduce redesign where conditions inside the retained building differ from assumptions made during early design.
Confirmation of the main contract now moves 99 City Road into active delivery after its pre-construction phase. With completion targeted for 2030, the immediate programme will centre on mobilisation, retained-structure works, enabling activity, and the interfaces needed to support the tower’s new floors, façade, and building-services infrastructure.
