“The plain wall surfaces on the long terrace blocks above podium level will be faced with small-scale white marble blocks with riven faces. These have a light-toned and lively appearance arising from the many irregular facets which also serve to break up the flow of rain-water over the surface and thus avoid the risk of streaking or local discolorization. The columns above the podium which support the residential blocks are of concrete, compounded of white spar aggregate in coloured cement matrix, polished to a fine surface. A similar material is used for the external precast lattice work structural grille which encases the towers. The exposed edges of balcony floors, spandrel panels and guard rails are faced with a small mosaic tile.”
Chamberlin, Powell & Bon, Architects “Barbican Redevelopment” April 1959
The pitted concrete of its buildings is one of the most noticeable features of the Barbican Estate. But if you thought that was part of the grand architectural design, you would be wrong. It was an economy measure. What Chamberlin, Powell & Bon really intended is set out above. The columns holding up buildings would have been white and smooth. The terrace blocks would have been glistening with a covering of multi-faceted marble blocks. The balconies would have been surfaced with mosaic tiles. The towers themselves would have had a coating of highly polished concrete made with white spar.
When these costly materials were turned down, Chamberlin, Powell & Bon’s answer was to pick-hammer the surface of the concrete. Personally, I feel they snatched victory from the jaws of defeat – just as they gave us the marvellous Gilbert bridge when the idea of a raised concrete road tunnel through the site was dropped.
The use of crudely finished concrete had been championed by Le Corbusier. In one of his buildings, Maison Jaoul, Le Corbusier had used crude concrete barrel vaults combined with oak woodwork and rustic brickwork. Perhaps the architects included this building in their travels. Certainly the use of barrel-vaulted roofs for the terrace blocks is one of the most characteristic motifs of the Barbican.
The pick hammered concrete is an effect which I find very easy to live with. The nearest thing to the original plan must be the Museum of London with its surface of small white tiles. It looks like a municipal swimming pool. When concrete discolours it at least resembles stone. When polished white stone discolours it looks like an old toilet.
Work on the buildings began in 1963. The Barbican estate, as eventually built, employed concrete in a much more monumental way than was envisaged in the comparatively delicate designs in the 1959 Report. This was made possible by using in situ reinforced concrete as the method of construction. The opportunity was provided by the engineers’ adoption of deep beams spanning between wide-spaced cross-walls, which Chamberlin Powell & Bon exploited as a feature particularly in the more exaggerated forms of the external balconies.