ONE of Scotland’s most famous companies has donated a five-figure sum to the appeal to help save the Hill House in Helensburgh.

News of the donation by confectioner Tunnock’s comes as a planning application for a giant box the height of four double-decker buses, aimed at protecting the building’s crumbling exterior, was formally lodged.

The box, with a solid metal roof on top and a steel frame and metal mesh around the sides, is aimed at giving the National Trust for Scotland time to consider options for a permanent fix for the famous Charles Rennie Mackintosh property.

The proposal for the 60-foot cage was unveiled in December, and last month the Trust announced the launch of an urgent appeal to raise £4.5 million towards the building’s restoration.

The exact sum donated by Tunnock’s is not being made public.

Announcing the Tunnock’s donation, Richard Williams, the Trust’s general manager for Glasgow and the west, said: “The five figure sum this great Scottish business has donated is a significant boost to our appeal and is especially apt as Tunnock’s is as much of a Scottish institution as the Trust itself, and indeed was trading more than a decade before Mackintosh put draughtsman’s pen to paper to come up with iconic Hill House design.

“We are delighted that Tunnock’s have chosen to be involved in what is such an important project for Scotland and has recognised that the Hill House and the work of Charles Rennie Mackintosh are part of Scotland’s heritage, and must be kept alive.

“Our appeal to save the Hill House for the nation is the largest ever launched by the National Trust for Scotland and the response has been magnificent.

“The individual examples of generosity have been quite humbling, as well as the many messages of support we have been receiving.

“Donations are coming in constantly and taking us ever nearer to our target – though we still need as much support as we can get."

On the formal lodging of the planning application, Mr Williams added: “We welcomed a team of planning officers to the building on Friday, March 23 and we are very grateful for their professional input and all the advice given to us.

“We hope that the public will offer supportive comments for our proposals and that we will hear of a positive outcome for our application in the near future.”