Work

Reimagining a compact City office building through light, space and carefully integrated rooftop amenity.

Situated at a prominent junction within the dense urban grain of the Leadenhall Market Conservation Area, the existing Edwardian office building is tightly bounded, with no external space and limited natural amenity. The brief tested how upward extension and internal reconfiguration could increase net lettable area while improving workplace quality and environmental performance.

TPM Studio led a RIBA Stage 1 feasibility exploring six extension scenarios, ranging from a single additional storey to two-storey additions incorporating roof-level terraces. Central to the strategy was the removal of the existing mansard and rooftop plant to create a clear platform for a lightweight, set-back addition. New upper levels were conceived as calm, contemporary insertions, using high-performance glazing and restrained detailing to admit generous daylight while preserving the primacy of the historic façade. The introduction of outdoor amenity at roof level reshapes the building’s relationship to the skyline, offering planted terraces and shared spaces within an otherwise hard urban context. Internally, reconfigured cores and exposed services support flexible, light-filled floorplates suited to evolving patterns of work.

The study demonstrates how modest vertical growth can unlock both commercial value and qualitative change. Increased floor area is paired with access to daylight, fresh air and green space, repositioning the building as a lighter, healthier workplace within the City’s dense financial core.