We collaborated with Make Architects to create a mixed-use development well-suited to its context adjacent to London’s Oxford Street for clients Great Portland Estates. The site comprises two L-shaped buildings, one incorporating office space, now home to Facebook, and the other residential units, with retail units at ground floor level. Both buildings represent a strong aesthetic of precast concrete cladding with ceramic slip bricks and metalwork which varies in depth and texture and responds to its environment.
Placing emphasis on sustainability and a high standard of living, the provision of a public landscaped central garden at ground level was key to this complex project. This not only delivers light to the basement office space via a sensitively positioned light well, but also informed the height and massing of the surrounding blocks, with the two uppermost floors of the eight-storey residential block to the north of the site set back to maximise sunlight.
Given its urban location, we dealt with a number of constraints and obstructions in the design process. We were able to analyse the substructure records of the previous Post Office building, which was demolished to ground level, to ensure that Mail Rail tunnels directly below the site remained unaffected, and to set the heights of three new basement levels above the tunnel access which incorporate office space and plant rooms. Before works commenced on site, complex ground modelling was used and a rigorous AIP process employed to ensure that movements of the tunnels would be maintained within acceptable limits.
A key driver in our approach was also to maximise economy and efficiency of construction, and this was partly achieved by reusing as much of the substructure as possible through comparative assessment of loadings created by the existing and proposed structures. Within the superstructure of the commercial building the focus is on marketability, designing subdivided floorplates to provide a range of office sizes. In both blocks we were able to strike a cost-effective balance between the thickness of floor slabs and column grid sizes.
Sustainable mixed-use scheme of office and residential centred around a new public realm in central London
Great Portland Estates
Office area: 22,556 m²
Retail area: 2,341 m²