GLASGOW — In May 2014, a small fire that started in the basement of the Charles Rennie Mackintosh building at the Glasgow School of Art here ripped through its wooden innards, working its way from the basement to the upper stories and destroying much of the west wing of a building long considered the jewel in Glasgow’s architectural crown.

Now, after two years of planning, preservation and debris removal, restoration on the Mackintosh is set to begin.

“It’s one of those unique moments where you have to rethink how you actually use a building,” said the art school’s director, Tom Inns. The devastating fire, he said, “was actually a significant catalyst in how we think about the space.”

Mackintosh, a Glaswegian architect, completed the Art Nouveau building in 1909. He was highly regarded in both Scotland and the German-speaking world, where his fondness for florid lines and Japanese-inspired designs synced well with tastes at the time. But his ability to readily secure work petered out in the years after the building’s completion. It wasn’t until after his death in 1928 that a renewed appreciation for his work, especially the Glasgow School of Art, flourished again. Still in regular use by students and administrators until the fire, the building attracted around 25,000 visitors each year.