Located within the Mayfair Conservation Area of London, 75-77 Brook Street is a seven-storey commercial development and is designed for the occupier, Clivedale (Sentia Ltd.), with the intention of complementing their headquarters in the adjacent building. The existing double-building structure will be demolished to make way for a single structure with a larger footprint, made possible by increasing the depth of the building at the rear. Terraces will situate at the rear of ground and top floor levels, with the roof also accommodating plant and generator facilities.

Key technical challenges

An added emphasis of importance was placed on architectural integrity of the building to ensure that the local area’s prominent heritage was maintained. Coordination of key stakeholders was a vital aspect of the project so that minimal disruption to the adjacent buildings was inflicted.

Key technical innovation

A precast reinforced concrete frame with 275mm deep post tensioned slabs has been adopted for the superstructure in order to reduce slab thicknesses and maximise the floor to ceiling heights without the need of any internal columns. In order to meet the high architectural aspiration, transfer structures have been adopted at various levels to deal with the offsetting of columns. A multitude of columns that change in size, shape and orientation are situated around of the building perimeter to maximize floor area of this particularly constrained building with 3 different party wall interfaces. The entire sixth floor level is used as a transfer level and connects the original adjacent building to the new structure.

Project Metrics

Project Value:
£15M GBP
Year Completed:
Building Metrics:
Seven-storey building, two-level basement

Project Metrics

Sentia Ltd
PLP Architects
Robert Bird Group Services:
Civil Engineering
Geotechnical Engineering
Structural Engineering

Environmental performance

  • BREEAM – “Very good”