LONDON—The Portuguese architect Álvaro Siza has won the Royal Gold Medal, reports the Guardian. Awarded by the Royal Institute of British Architects (RIBA) and personally approved by the Queen, the medal is considered Britain's most prestigious architecture prize.

Siza, 78, is known for his sculptural buildings that are inspired by their sites. His best known structures, including the Adega Mayor winery and the Evora housing development, are in Portugal. Although Siza has not produced a permanent building in Britain, his work has had a vast influence on British architects.

"Alvaro Siza is simply a profoundly complete architect who defies categorization," RIBA said when it announced the prize. "The forging of a masterful and seemingly inevitable architecture out of the possibilities of a site is one of the supreme characteristics of his work."

Other prizes Siza has won include the Pritzker Prize in 1992, the Alvar Aalto Medal in 1998, and the Wolf Prize in Arts in 2001.

Past winners of the Royal Gold Medal include Frank Gehry, Herzog and de Meuron, and Frei Otto.