Sir James studied architecture at Cambridge – where his tutors included Nikolaus Pevsner and Geoffrey Webb – and went on to become an influential teacher himself at Edinburgh College of Art and Heriot-Watt University, where he set up the exemplary conservation course.

Alongside Graham Law he founded LDN Architects in 1957: the practice soon expanded and produced some of the most celebrated Scottish buildings of the 1970s including the seminal Eden Court and Pitlochry Festival Theatres and, in the 1990s, the Edinburgh Festival Theatre. The practice continues to thrive today.

As well as his contribution to the RIAS – in recognition of which he was awarded Lifetime Achievement Award – Sir James held numerous other positions including deputy chairman of the Edinburgh International Festival, trustee of the Architectural Heritage Fund, president of the Scottish Civic Trust and trustee of the Theatres Trust. He was appointed CBE in 1976 for services to architecture and education, and knighted in 1996.

The RIAS said Sir James was “an outstanding champion of architecture in Scotland and will be deeply missed”.

“The Royal Incorporation of Architects in Scotland is thankful for the life and work of Sir James Dunbar-Nasmith, and we send our condolences to his friends, family and all who knew him,” it added.