30 Cannon Street is a modern office building on Cannon Street in the City of London, close to Mansion House underground station. It was designed by Whinney, Son & Austen Hall as an office building for Crédit Lyonnais and built between 1974 and 1977. It became a Grade II listed building in 2015. The location was formerly the site of the city church of St Mildred, Bread Street, designed by

Christopher Wren Sir Christopher Wren PRS FRS (; – ) was one of the most highly acclaimed English architects in history, as well as an anatomist, astronomer, geometer, and mathematician-physicist. He was accorded responsibility for rebuilding 52 churches ...

after the medieval church was destroyed in the

Great Fire of London The Great Fire of London was a major conflagration that swept through central London from Sunday 2 September to Thursday 6 September 1666, gutting the medieval City of London inside the old Roman city wall, while also extending past the ...

; the Wren church was bombed and destroyed in the Second World War. The site was one of the last bomb sites in London to be redeveloped. The building has six storeys with a raised basement. Its height was limited due to its proximity to

St Paul's Cathedral St Paul's Cathedral is an Anglican cathedral in London and is the seat of the Bishop of London. The cathedral serves as the mother church of the Diocese of London. It is on Ludgate Hill at the highest point of the City of London and is a Grad ...

to the north-west, and the high water table prevented a

sub-basement A basement or cellar is one or more Storey, floors of a building that are completely or partly below the storey, ground floor. It generally is used as a utility space for a building, where such items as the Furnace (house heating), furnace, ...

. Its shape was constrained by its triangular island site, east of Bread Street, west of the junction where Cannon Street crosses Queen Victoria Street. It originally had an entrance on each façade (the western one on Bread Street has been removed) and a large central circular banking hall (also now removed). Although built for Crédit Lyonnais, it was designed so it could occupied by three separate banks, one in each corner of the building, but the interior has been significantly altered. The façades are characterised by tiers of repeating arched white frames around recessed windows of bronze-tinted glass, with each tier separated by a black granite string course which incorporates hidden drainage. The cladding units are pre-cast double-skinned wide modules of glass fibre reinforced cement (GRC), using a mixture of Portland cement with 5% alkali-resistant

glass fibre Glass fiber ( or glass fibre) is a material consisting of numerous extremely fine fibers of glass. Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the inventio ...

as reinforcement. It was the first building in the world to be entirely clad with GRC panels. Triple-width modules on the ground floor wide have two canted windowpanes meeting at an angle, with similar modules repeated on upper floors to either side of the entrances. The slim profile and light weight of the GRC panels allowed the architect to slope the walls outward at an angle of five degrees, with each floor slightly larger than the one below, creating extra office space. The units of the partial upper floor are inverted, creating a roof line that resembles a crown to the north side and at the eastern end; a roof deck occupies at the south-western corner. Railings on the street have shapes similar to the cladding panels. File:30 Cannon Street. - geograph.org.uk - 519453.jpg, View in 2007 from south-east File:30 Cannon Street - geograph.org.uk - 397150.jpg, Details of windows and entrance in 2007

References

English Heritage Announces Listing of Post-War Office Buildings
English Heritage, 28 January 2015 *

30 Cannon Street
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100 Buildings 100 Years – 1977: 30 Cannon Street, London
Twentieth Century Society Grade II listed buildings in the City of London Office buildings completed in 1958 Office buildings in London Modern architecture in the United Kingdom