Keith Williams

Most buildings are made from positive components – bricks, steel, stone – which are assembled in a given sequence to make the final form.

With concrete we do the reverse. We shutter space, making a negative into which the liquid concrete is poured to solidify into a positive: the structure, the form, the architecture. Rachel Whiteread’s House, a temporary artwork from 1993-94, viscerally exploited that concept, giving form to the private internal space of an ordinary Victorian house by pumping it full of concrete. She then peeled away the external masonry skin to expose the resultant cast. Humble, domestic space was solidified, and exposed to the city for the first time. Brilliant!

The Capitol Complex at Chandigarh by Le Corbusier is extraordinary. The concrete is rough, raw and heavy but the huge scale and power of the architecture and the drama of the forms in the light of northern Punjab produce the richest of architectural monumentality. I had admired it since my student days, but when I finally got to visit in 2007 I was blown away. It is one of the finest ensembles of postwar architecture on the planet – an ancient land reinventing itself to take its place in the modern era through radical sculptural architecture in concrete.

Concrete’s immense heft can also be subverted to great effect. At the Church of San Giovanni Battista, Campi Bisenzio, Giovanni Michelucci deploys delicate diagonal struts to support the roof, which appears like a curved cloth draped across the space. There’s nothing weightless about it – it looks like a very, very heavy cloth. It’s remarkable how he’s made concrete do that, almost in the way that sculptors like Canova could carve marble into swaths of cloth.

We sometimes forget not just the weight of concrete, but the immense strength needed to hold it while it cures. It’s a raw, forceful process – sometimes formwork can simply burst – and it’s unusual for concrete to come out looking utterly beautiful. Achieving a fine finish is hard: at the Novium museum in Chichester (CQ 242) we used an aggregate mix rich in quartz to introduce a sparkle into the surfaces, but it involved quite a labour-intensive process of brushing and gently sanding the surface.

This is partly what makes Tadao Ando’s work so compelling. At the Church on the Water, exquisitely textured concrete combines with water and light in perfect harmony to create an exquisite numinous ensemble. It is tiny but beautifully ordered in its geometry and craft.

Keith Williams is founder and director of design at Keith Williams Architects and chair of trustees of Docomomo UK

Photos Alex MacNaughton / Alamy Stock Photo; Keith Williams