The ‘Cheesegrater’ embraces ideas about architecture, planning and the public, writes Paul Finch
Rogers Stirk Harbour’s City of London landmark, colloquially known as the ‘Cheesegrater’, because of its angled glazed facade, will be topped out by Boris Johnson later this month. The 75,000m² building is 51 per cent let, at rents of more than £60 per square foot, and promises to be a significant commercial success for developer British Land and various funding partners.
One of those lettings has given the London insurance market a huge psychological boost: the giant US company, Aon, is not only taking several floors in the project, but is moving its top management team from its current headquarters in Chicago. This follows another important decision, by the Boston-based WR Berkley group, to build a European headquarters, designed by KPF for a site diagonally opposite the Cheesegrater and known as the ‘Scalpel’. You have to have a nickname.
That has yet to start construction, while the RSH+P scheme will complete in a year’s time, when its true urban significance will become apparent. It involves the most generous public realm contribution to the City for many years, in the form of a gigantic cut-out at the base of the building, providing a huge volume and a flowing ground plane which links with the piazza of the adjacent building, originally the Commercial Union Tower (now Aviva).
The scale of the public space will do what Richard Rogers had difficulty in achieving at the Lloyd’s of London headquarters. At Lloyd’s it was only possible to use Leadenhall Market for this purpose, but that is an interior environment at the back of the insurance building.
The Cheesegrater is an entirely different story, since the public space, with its 30m soffit, is essentially external. So we have a highly unusual example of the same architectural practice working on both sides of the street, able to complement an earlier building via the creation of new street life opposite.
Valuing this public realm element is difficult, except by assuming that the office space could have come to ground, with a conventional entrance. Multiply the additional potential huge office area by £60 per square foot, apply a yield value for prime City of London office space and you begin to understand, even assuming a construction cost of about £300 per square foot, the scale of the public contribution that the developer and development have made to the Square Mile.
Generous public realm provision is part and parcel of a calculation about commercial value, of course. Amenity creates value. This is not a building where it would have been possible to provide public, or quasi-public space at the top, since the form of the building diminishes sharply, in contrast with Rafael Viñoly’s nearby ‘Walkie Talkie’, where the top of the building is given over to a substantial winter garden (very visible from the top of 120 Leadenhall). The alternative was to provide public space at the base. Similarly, the decision to provide an angled facade meant that a tall building (225m) in this location would not interfere with views of the dome of St Paul’s from Fleet Street, in particular from just outside the Cheshire Cheese public house (rebuilt 1667).
Does the form of this remarkable building simply follow function and external programmatic demands? Only as part of a broader architectural approach to the provision of City office buildings, explored by RSH director Graham Stirk in his designs for 88 Wood Street, and the Lloyds Registry Building. All in all, the Cheesegrater is a speculative office development of extraordinary quality, built in an exemplary way by Laing O’Rourke, with engineering by Arup. It sets standards that few are likely to emulate.