30 St Mary Axe

London’s first ecological tall building and an instantly recognisable addition to the city’s skyline, this headquarters designed for Swiss Re is rooted in a radical approach − technically, architecturally, socially and spatially. Forty-one storeys high, it provides 46,400 square metres net of office space together with an arcade of shops and cafés accessed from a newly created piazza. At the summit is a club room that offers a spectacular 360-degree panorama across the capital.

Generated by a circular plan, with a radial geometry, the building widens in profile as it rises and tapers towards its apex. This distinctive form responds to the constraints of the site: the building appears more slender than a rectangular block of equivalent size and the slimming of its profile towards the base maximises the public realm at street level

Environmentally, its profile reduces wind deflections compared with a rectilinear tower of similar size, helping to maintain a comfortable environment at ground level, and creates external pressure differentials that are exploited to drive a unique system of natural ventilation.

Conceptually the tower develops ideas explored in the Commerzbank and before that in the Climatroffice, a theoretical project with Buckminster Fuller that suggested a new rapport between nature and the workplace, its energy-conscious enclosure resolving walls and roof into a continuous triangulated skin. Here, the tower’s diagonally braced structure allows column-free floor space and a fully glazed facade, which opens up the building to light and views.

Atria between the radiating fingers of each floor link vertically to form a series of informal break-out spaces that spiral up the building. These spaces are a natural social focus – places for refreshment points and meeting areas – and function as the building’s ‘lungs’, distributing fresh air drawn in through opening panels in the facade. This system reduces the building’s reliance on air conditioning and together with other sustainable measures, means that it uses only half the energy consumed by a conventionally air-conditioned office tower.

Project When the Architect Foster and Partners were designing the entrance on the world renowned Swiss Re building in London, they called upon Boon Edam Limited for an elegant and environmentally sealed entrance lobby.

The use of revolving doors in the entrance façade has helped in creating London’s first environmentally sustainable Skyscraper by reducing the amount of energy lost through typical entrance solutions such as manual or automatic swing, sliding and folding doors.

Product Working directly with Skanska, the Main Contractor on the project and in conjunction with Schmidlin, the Curtain Walling Contractor, Boon Edam Limited supplied and installed four Crystal Tourniket revolving doors.

The Crystal Tourniket, which is the original all glass revolving door, is both aesthetically pleasing and energy efficient and complements the entrance screen and building façade.

The Crystal Tourniket is available as a manual or automatic door supplied in a wide range of surface finishes and glass options.

Arup engineers realised the building’s radical form through the creation of an efficient external diagrid system of intersecting steel sections around the tower’s perimeter.

30 St Mary Axe also known as ‘The Gherkin’ is the second tallest building in the city of London. The building’s tapered circular form was designed to provide maximum, internal column free of fice space with minimum external visual bulk, and to create a new public city plaza. The perimeter diagrid is formed from intersecting steel tubes that frame the six spiralling light wells, it is an integral part of the ventilation strategy that allows the building to operate without ventilation at certain times of the year . Arup used extensive 3D computer modelling to determine the size of the steel frame. It enabled the steel contractor to generate information needed to produce the 10,000 tonnes of steel in the buildings. This made the process of going from drawing board to fabrication as simple as possible for the varying floor sizes.