IN Brief:
- Mace has been appointed to redevelop the former City Hall at 110 Queen’s Walk.
- The building will grow from approximately 18,000 sq m to 22,000 sq m.
- New cladding, services, terraces, retail space, and public-realm works form the programme.
Mace has been appointed by St Martin’s Property Group to deliver the estimated £150m redevelopment of London’s former City Hall at 110 Queen’s Walk.
Construction is beginning in July on a programme that will expand the riverside building from approximately 18,000 sq m to 22,000 sq m. Although the circular footprint and distinctive curved form will remain recognisable, substantial changes are planned for the façade, internal floorplates, roofscape, services, and surrounding public spaces.
Mace originally delivered the ten-storey Foster + Partners building before it opened in 2002. The Greater London Authority vacated the property in 2021 and moved to the Royal Docks, leaving one of the capital’s most prominent civic buildings without its original use.
Designed by Gensler, the replacement scheme will convert the property into a mixed-use workplace and public destination. Ground-floor retail, enlarged office accommodation, new terraces, end-of-trip facilities, and upgrades to the adjoining Scoop and landscaped areas are included within the current scope.
Through a full replacement of the cladding and glazing, the project will alter both the environmental performance and appearance of the envelope. Extensions to the floorplates will reduce the pronounced lean associated with the original design, creating more regular commercial space while retaining enough of the geometry to preserve the building’s identity on the South Bank.
Within the structure, part of the atrium will be infilled to increase usable area, while mechanical, electrical, and public-health installations designed for a civic office completed almost a quarter of a century ago will be replaced. Mace will deliver shell-and-core accommodation capable of supporting future tenants and their individual fit-out requirements.
Waterman is providing structural and building-services engineering support. Integrating additional loads, larger floorplates, terraces, new plant, replacement façades, and revised circulation into an existing structure will require detailed verification of the original frame and foundations.
As elements are removed and new sections introduced, temporary stability will need to be maintained through a carefully controlled sequence. Existing load paths may change several times before the permanent works are complete, particularly where façade replacement, atrium infill, structural extensions, and services installation overlap.
The appointment continues the shift towards retaining and substantially adapting prominent commercial buildings rather than clearing sites for complete redevelopment. Structural retention can preserve a large proportion of the carbon already invested in foundations and frames, although complex retrofit is rarely a light-touch alternative to new construction.
Existing buildings bring concealed interfaces, residual tolerances, incomplete records, and materials whose condition may only become clear after opening-up work begins. Surveys must therefore remain connected to design development and construction planning rather than being treated as a closed pre-construction exercise.
The geometry of City Hall adds another layer of coordination. Curved façades, sloping elevations, irregular floorplates, and close relationships between structure and envelope provide less tolerance for late decisions than a conventional rectilinear office building.
Digital surveys and coordinated models will be central to manufacturing replacement components that fit the retained structure. Where original tolerances, movement, and later alterations differ from the available records, fabrication data will need to reflect measured conditions rather than historic drawings alone.
London also remains one of the world’s most expensive construction markets, with recent cost comparisons placing the capital second globally. Logistics restrictions, limited storage, neighbouring businesses, public routes, riverfront constraints, and extensive stakeholder requirements can all add substantially to project preliminaries.
At Queen’s Walk, heavy construction activity must be separated from established pedestrian routes and surrounding cultural venues. Deliveries, façade removal, lifting, waste movements, noise, dust, and temporary closures will be planned around an area that continues to attract workers, residents, tourists, and event audiences throughout the week.
Replacing the services strategy also creates decisions around capacity, flexibility, and internal space. Modern offices carry different cooling, ventilation, electrical, digital, security, and resilience requirements from those specified in the late 1990s.
New systems must meet current performance expectations without consuming so much floor or ceiling space that the commercial benefit of extending the building is eroded. Plant replacement, riser positions, distribution routes, maintenance access, and tenant metering will need to be resolved alongside the retained structure.
Commercial retrofit also depends on the relationship between base-build performance and later tenant fit-outs. A high-performing shell can still be undermined by inefficient internal systems, excessive occupational loads, or fit-out decisions that restrict future adaptability.
By enlarging the floors while retaining the principal structure, St Martin’s Property Group is attempting to reposition a highly specialised civic building for the current office market. Letting performance will depend on whether the new accommodation can combine efficient layouts, lower operating demand, strong amenities, and a recognisable riverside identity.
Mace’s return gives the delivery team direct organisational experience of how the building was originally assembled, although both the physical structure and regulatory environment have changed considerably since 2002. Construction will now establish how much of the original engineering can be preserved while creating a commercially flexible building for its next operating life.
