I had the daily pleasure of seeing the west wing of the Glasgow School of Art, with its castle-like stonework and triple tall oriels rising dramatically from the steep slope of Scott Street, when, for more than a decade, I taught architectural history at the Mackintosh School of Architecture. I also had the privilege of being able to explore the interior of the School of Art at will. And I became more and more impressed. It was a building that worked, though made of ordinary and traditional materials – stone, timber and iron – on a limited budget; it was the product of a mind at once practical and imaginative. Throughout, as my then boss, Andy MacMillan, put it, Mackintosh ‘demonstrates a creative exploitation of each and every specific requirement, seizing the opportunity to create an architectural “event” through some feat of invention’.