ONE of Charles Rennie Mackintosh's most famous creations, the Willow Tea Rooms in Glasgow, could not have survived another winter in its present condition, experts have found.

A small amount of the building's external render has been removed this week by its owners, the Willow Tea Rooms Trust, who had grown alarmed by the state of the exterior.

A major £4 million project to restore and revamp the famous tea rooms, opened in 1904 and designed by Mackintosh, will get under way later this year, with a competition for architects already open.

A conservation report had highlighted that the render on the facing of the tearooms, in the city's Sauchiehall Street, could be in danger of falling away, with risk to the public.

On Thursday, a cherry picker, with relevant experts and Celia Sincair, chair of the Trust who bought the dilapidated building last year, studied the potential damage.

Only a small amount of the render was dangerous and had to be removed.

However a conservation expert said that the render would not have "survived another winter" in its current condition.

Ms Sinclair said: "We were alarmed when the report came through that the original plaster applied to the brick surface on the front of the building was water damaged and a potential danger.

"Fortunately, it wasn't as serious as first feared.

"We've had experts and the city planning department evaluate it and remove a small amount, but the rest can safely remain until the project starts in earnest with the appointment of the project architects firm later this year.

"It goes to show just how fortunate we are to have started this project when new did. I doubt the Tea Rooms would have survived another winter and we would have lost so much as a result."

The competition has been launched to find the architectural firm that will lead a £4m overhaul of the tearooms.

The revamp is planned to be completed on time for Mackintosh's 150th birthday in 2018.

The project will restore the A-listed 1903 cafe and create a new visitor centre next door.

The plan is for the project to restore the building as far as possible to its original condition.

The neighbouring tenement block, also owned by the trust, will become a visitor centre, including a shop, exhibition space, offices and a kitchen.

Five teams will be shortlisted for the project.

Stewart Brown, a trustee, said: "We're very keen to hear from younger practices who have good ideas for the building next door which should be exciting in its own right, but not detract from the tearooms."

Adverts for the competition have now been published and firms have until July 27 to apply.

There has been 47 notifications of interest from architect firms across the UK already.

The Mackintosh-designed building and interiors, which were designed and built in 1903 for Kate Cranston, are situated in Sauchiehall Street.

The Willow Tea Rooms opened in November 1904.