Portfolio

This project retained the Charles Holden façade on this prominent Oxford Street location dating back to 1910.

Seven storeys of new, efficient structure will be constructed above ground behind with a new landmark façade on Oxford Street. Post tensioned slabs will be used to maximise the column grid and to maintain an overall building height below a protected sightline threshold.

We have been instrumental in achieving a vast increase in net lettable area by working closely with various third parties. This allowed us to justify a landmark basement dig within the constraints of an existing Royal Mail tunnel, two LUL Central line tunnels, a Thames Water sewer and the protection zone for the proposed Cross Rail 2 route. Three levels of basements below the existing basement are to be constructed within a secant piled retaining wall inset from the existing façade.

Both the Central line and the Mail Rail tunnel run directly below the site. Ground movement assessments tailored to the phase of the project have been undertaken to identify tunnel movement and lining stress increases.

We were appointed to the Metro Bank design team developing all new proposed buildings, new store fit-outs, and major refurbishment works and alterations to existing buildings. To date, we have been appointed on over 155 projects stores, with 70 completed and another 37 live. 

To meet the clients brief of creating open banking halls, often with double-height space, we pushed the boundaries of structural design to alter the fabric of existing structures. The below-ground drainage has to be adapted to the specific constraints of each site on a project-by-project basis. It can include diversions of the existing drainage of adjacent buildings to suit the new internal layout.

The diverse projects and locations often require additional civil engineering elements such as external works (e.g. realignment of car parking), vehicle tracking across external areas, setting of external levels to comply with disabled access and Flood Risk Assessments where necessary. These projects are on fast roll-out programmes, two projects have been successfully delivered with several more reaching completion and others under construction.

The Parcels Building — known as such because it sits atop a former ‘Mail Rail’ station — occupies the corner of Oxford and Duke Streets in London’s West End, across from the world-famous Selfridges department store. As part of an effort to lift the character of the area, the Parcels Building refurbishment includes installing a new façade to the 1950s building and adding a storey to the part-retail, part-office scheme.

The emphasis on external appearance meant that the façade was a focal point of the development. Grafton Architects designed a grid of Portland stone, with 1.4m-wide Pierre Bleue piers that rise from ground to roof level, recessed lintels, and bands of deep horizontal shading elements at each level. On Oxford Street, the piers protrude in a softly angled form, while on Duke Street they lie flush with the elevation.

As refined and elegant as it is, the heavy new stone façade required structural innovation to support its projection from the existing frame. To achieve this, we developed a bespoke bracketry system which applied load to the columns and beams in a way that was sympathetic to the existing structural frame, reducing the need for strengthening works. Retaining the structure saved 513T CO₂e.

We provided structural and civil engineering services for the rebuilding of the flagship Ermenegildo Zegna store on New Bond Street. The existing four and five-storey double retail units were demolished and replaced with a new five-storey R.C. frame building, built independently of the neighbouring buildings which were retained. This ensured consistent floor levels were achieved within the same footprint.

To achieve an additional basement floor beneath the existing basement, we designed careful coordination between the existing and new structure. This included underpinning most of the existing structure, through varying ground conditions and a high-water table. Outline temporary works proposals we also developed along with the design of the permanent structure to ensure the new retail building was built quickly and safely within a very constrained site.