Denys Lasdun, the National's concrete craftsman, dies aged 86

Denys Lasdun, the architect who designed the National Theatre on the South Bank in London, has died.

Denys Lasdun, the architect who designed the National Theatre on the South Bank in London, has died.

Sir Denys, who was 86, is regarded as one of the greatest 20th-century architects. His primary inspirations were Le Corbusier and Cubist painting.

Friends said he had seemed well at Christmas and attended several parties at New Year. He was taken to Charing Cross Hospital in the capital earlier this week feeling feverish, and died from double pneumonia yesterday shortly after midnight.

Gavin Stamp, chairman of the conservation group Twentieth Century Society, said Sir Denys had "tremendous integrity. He is the last of his generation who began working before the war. He was an extremely nice man and verygenial. He believed totally in what he was doing, and was an unashamed proponent of concrete construction."

Sir Peter Hall, who was director of the National Theatre when it opened in 1976, said: "Denys Lasdun built for the National Theatre three very different stages that work - a great achievement in an age of ungainly auditoriums - and he enclosed them in a great modern yet classical building, which is now an indispensable part of the London landscape. To my generation of theatre people he was an inspiration."

Sir Denys's career began in the early 1930s soon after Modernism was introduced to Britain from the Continent. One of his main themes was the idea of buildings as urban landscapes formed from interlocking spaces and levels, like artificial hills and valleys. He called the platforms and levels of his buildings strata. "It's a geological term which goes very well with concrete. These platforms and terraces are public spaces, domains, an extension of the city," he said.

Dennis Sharp, a council member and former general editor at the Architectural Association, where Sir Denys began his training, said he was a remarkable architect. "He was admired throughout the world. He took a medium like reinforced concrete that was not popular and turned it into something special."