FSW: Bloomberg Façade

Friction Stir Welded Façade of the Bloomberg Building in London's Cannon Street

Friction Stir Welded Façade of the Bloomberg Building in Cannon Street in London

© The wub, CC BY-SA 4.0

Friction Stir Welding (FSW) was used to create the façade panels of the Bloomberg building on Cannon Street in London-Walbrook, which had a price tag of £1bn.[1[2] This was a joint project between Sir Robert McAlpine and the façade builder Josef Gartner, founded in 1868 in Gundelfingen, Bavaria, according to plans by Foster + Partners. The bronze cladding has a sculptural form that required high quality fabrication and finishing techniques. These included friction stir welding, which is also used by the aerospace industry.[1]


Fins made from friction stir welded bronze sheets

© Paul Trafford, CC BY 2.0


Stunning view of St. Peter's from the 'Pantry' on the sixth floor of the building

© The wubCC BY-SA 4.0

The sophisticated bronze louvres on the building's façade provide ventilation and shading. Together with intelligent sensors that regulate the air flow, they are expected to save up to 300 tonnes of CO2 per year.[3]  Since bronze sheets cannot be produced in the required size in rolling mills, several sheet strips were welded together in Japan using the friction stir welding process, whereby the low distortion and low visibility of the FSW seam on the root side are important process advantages.


Friction stir welding of up to 4 x 2.8 m (13 x 9 ft) large bronze sheets at Kikukawa[5][6][7]

1:42 min © Kikukawa, 17 November 2020



Project of the Year Award 2019 of the Society of Façade Engineering (SFE)

The 2019 'Project of the Year - Newbuild' award was received by Chris Hall and Tom Howse, who were both involved in the production of this façade for Sir Robert McAlpine's Bloomberg project. The winners were announced at the celebratory Glass Supper event on 10 December at Guild Hall, Basinghall, London.[1][4]


The Society of Façade Engineering (SFE) International Awards recognise projects that demonstrate outstanding technical design and/or research and have made a significant contribution to the discipline of façade engineering.[1]


Further Awards

  • RIBA London Award (2018)
  • RIBA National Award (2018)
  • BREEAM Regional Project for Western Europe
  • BREEAM Commercial Projects - Design Winner
  • Stirling Prize 2018[8][9]
  • Structural Steel Design Award 2018