Leadenhall Building ("The Cheese Grater") - Leadenhall Street, London, UK
N 51° 30.812 W 000° 04.939
30U E 702444 N 5710970
This 50 storey tower opposite Lloyd’s of London rises to a height of 224.5 metres (802 feet). It has been given the name "The Cheese Grater" due to its wedge shape that makes it look like a kitchen utensil of the same name.
Waymark Code: WMH5TW
Location: London, United Kingdom
Date Posted: 05/27/2013
Views: 10
The architects, Richard Rogers website, tells us:
The building comprises a number of distinct architectural elements that provide clarity to the composition both as a whole and as a legible expression of its constituent parts. These elements include the primary stability structure, the ladder frame, the office floor plates, the northern support core, the external envelope and the public realm.
The structure aims to reinforce the geometry defined by the development envelope, which in turn creates the distinctive tapering form, and takes the form of a perimeter braced ‘tube’ that defines the extent of the floor plates. The ladder frame contributes to the vertical emphasis of the building, and encloses the fire-fighting cores that serve the office floors. The frame also visually anchors the building to the ground.
The office floors take the form of simple rectangular floor plates which progressively diminish in depth by 750 millimetres towards the apex. Office floors are connected to the structural ‘tube’ at every floor level without the need for secondary vertical columns at the perimeter.
The northern support core is conceived as a detached tower containing all passenger and goods lifts, service risers, on-floor plant and WCs. Three groups of passenger lifts serve the low, mid and high rise sections of the building, and are connected by two transfer lobbies at levels ten and 24.
The position of the northern support core relative to the office areas means that the structure is not required to be over-clad with fire protection, allowing the whole to be designed and expressed as visible steelwork. This articulated steel frame provides clarity to the whole assemblage.
The highly transparent glazed enclosure makes manifest the structure and movement systems within; its physical presence is a striking and dynamic addition to the City and a unique spectacle for the enjoyment for passers-by.
The building is designed to express all the constituent elements behind a single glazed envelope. Facades to the office areas require the highest comfort criteria in relation to heat loss, daylight, glare control and solar gain. Here, the facade is supplemented with an internal layer of double-glazing, forming a cavity which incorporates the structural frame. The external glazing incorporates vents at node levels to allow outside air to enter and discharge from the cavity. Controlled blinds in the cavity automatically adjust to limit unwanted solar gain and glare.
The lower levels of the building are recessed on a raking diagonal to create a large public space that opens up to the south. The spectacular scale of the semi-enclosed, cathedral-like space is without precedent in London and will create a major new meeting place and a unique destination in itself. Overlooking the space are generous terrace areas within a bar and restaurant that provide animation and views into the public space and beyond. This enclosure is open at ground level to give access from all directions. The public space is fully accessible by means of a large, gently raked surface connecting St Helen’s Square with Leadenhall Street.
A PDF document, linked to the above webpage, tells us:
This 50 storey tower opposite Lloyd’s of London rises to a height of 224.5 metres (802 feet), its slender form creating its own distinctive profile within an emerging cluster of tall buildings in this part of the City of London. The building’s tapering profile is prompted by a requirement to respect views of St Paul’s Cathedral, in particular from Fleet Street.
The tower’s design ensures that from this key vantage point the cathedral’s dome is still framed by a clear expanse of sky. The office floors, containing the highest quality office space, take the form of rectangular floor plates which progressively diminish in depth towards the apex. Instead of a traditional central core providing structural stability, the building employs a full perimeter braced tube which defines the perimeter of the office floor plates and creates stability under wind loads. The circulation and servicing core is located in a detached north-facing tower, containing passenger and goods lifts, service risers and on-floor plant and WCs.
The building’s envelope expresses the diversity of what it encloses, reinforcing the composition and providing legibility to the primary elements. Although the tower occupies the entire site, the scheme delivers an unprecedented allocation of public space – the lower levels are recessed on a raking diagonal to create a spectacular, sunlit seven-storey-high space complete with shops, exhibition space, soft landscaping and trees.
This public space offers a half-acre extension to the adjacent piazza of St Helen’s Square. Overlooking the space is a public bar and restaurant served by glazed lifts. This new public space will provide a rare oasis within the dense urban character of the City of London.
The Emporis website contains facts about the building:
- A planning application was submitted to the Corporation of London on the 10th February 2004.
- The redevelopment involved the demolition of 122 Leadenhall Street, a 14-storey office tower built in 1969.
- The building's height above ordnance datum (AOD) is 239.4 metres (785 feet).
- The vertical circulation is located on the north side, opposite the lobby and main entrance facing The Lloyd's Building.
- The floor plates vary in size which allows for great flexibility in providing office space which can be cellular or open-plan.
- The open space at the base rises to seven storeys and contains trees and retail amenities.
- Each floor plate on the south side is stepped back by .75 metres from the one below, resulting in the distinctive wedge shape when viewed from the east and west.
- The distinctive wedge shape is designed to virtually eliminate the building intruding into the sight-line of St. Paul's Cathedral when viewed along Fleet Street and up Ludgate Hill.
- Of the 29 lifts, 22 are exterior, glass, and fully scenic.
- The ladder frame on the rear (north side) encloses the fire-fighting cores which serve the office floors.
- The support core to the north is conceived as a separate tower which contains the passenger and freight lifts, service risers, floor plant and lavatories.
- The low-, mid- and high-rise sections are served by three groups of passenger lifts which are connected by two transfer lobbies at floors ten and twenty-four respectively.
- Because of the northern support core's relative position to the office floors, the structure doesn't require over-cladding with fire protection, meaning it can be designed and expressed as visible steelwork.
- Solar gain to the office areas is countered with the incorporation of remotely controlled blinds.
Height (architectural): 224.50 m
Height (roof): 219.79 m
Height (main roof): 196.09 m
Height (top floor): 192.09 m
Floors (above ground): 50
Construction start: 2008
Construction end: 2014
Elevators: 29
Escalators: 3