The announcement follows an international competition to find an architecture and design practice capable not only of restoring and renovating The Willow Tea Rooms, which were designed by Charles Rennie Mackintosh for entrepreneur Kate Cranston in 1903, but also creating a state of the art visitor, educational and exhibition centre at 215 Sauchiehall Street, directly adjacent to the tea rooms.

Celia Sinclair, founder and chair of The Willow Tea Rooms Trust, which was established to save and restore The Willow Tea Rooms for the City of Glasgow, said: “We know it is a very challenging project for any architectural firm but we were tremendously impressed by Simpson & Brown’s conservation expertise and by the ideas they put forward for the new Mackintosh centre.

“They will combine the old with the new, perfectly contrasting modern and impressive design with the original splendour of the only remaining Charles Rennie Mackintosh designed tea rooms.”

With the diversity of the project, Edinburgh-based Simpson & Brown has assembled a team of architectural conservation and design specialists from companies including Studioarc, Rybka, David Narro Associates, Alliance CDM, Building Learning and People Friendly Design.

John Sanders, partner and heritage specialist at Simpson & Brown will lead the project team and said: “The complexity of the project required that we bring together a team of experts in their fields to ensure every detail is taken care of and we’ve selected people we respect and admire to work with us.

“The key to the success of the design lies with the Trust’s acquisition of 215 Sauchiehall Street, which will allow us not only to create a world class visitor centre but provide amenities, such as lifts and other facilities, which will be accessible from, but not interfere with, the tea rooms themselves or the experience they provide. Essentially we’re taking the tea rooms back to their celebrated past but also taking them forward in time to make it a unique architectural and design experience.”

The cost of the project is estimated currently at £7 million, £1m of which is required to repair and make The Willow Tea Rooms building fully wind and watertight, and for the restoration work on features either lost over the years or damaged as a result of the decline in the fabric of the building.

The Willow Tea Rooms Trust hopes to raise the necessary funding from public and private sector donors as well as from the large number of Charles Rennie Mackintosh admirers around the world.

“We are creating something truly special and sustainable in Sauchiehall Street that will help to create jobs, support tourism, and celebrate and safeguard the legacy of Charles Rennie Mackintosh,” added Celia Sinclair. “Work will be progressing as quickly as possible to enable us to have everything in place for 2018, which is the 150th anniversary of his birth.”