The 22-bedroom house, built in 1852, will host weddings, dinners and conferences, while the grounds will be promoted for outdoor activities, such as highland games, treasure hunts and falconry.

The decision by owner Tessa Tennant comes two-and-a-half years after she announced the house would cease to be run as a commercial enterprise and would return to the role of family home for herself, her son Euan, 25, and husband Bill Staempfli.

Before that, the house was available for weekend hire at up to £14,000 and stars who hired the mansion included the model Kate Moss who enjoyed a New Year bash there with the smart set in 2005.

The new business plan will be fundamentally different, with guests restricted to the ground floor and no sleeping accommodation available. The marketing and management of all future activities on the estate has been exclusively signed over to Edinburgh-based event specialists K & N Travel Associates.

And that, said Ms Tennant, will present important spin-off business for local hotels and guest houses.

“When it became clear that, in order the continue operating the accommodation side of the business, we would have to make major changes to the house’s interior architecture, we simply chose to cease operations,” she told TheSouthern. “Glen House is first and foremost a private family home.

“But we were surprised by the amount of interest that continued, unsolicited, after the business closed in January 2007. Indeed, we have been receiving calls most weeks from former clients and through word of mouth referrals and it was rather sad to have to say ‘no’ all the time.

“The team at K & M understands the new use limitations and has built its marketing strategy to work within this framework. It will be looking to local hotels and other houses offering accommodation to help clients who would like to stay in the area overnight.”

And Ms Tennant admitted there was a financial imperative in the decision.

“The Glen is a magnificent place, but with some magnificent challenges and the cost of upkeep on a property such as this can make your eyes water.

“Anyone holding an event here can take pride in the fact they are helping support an important part of Scotland’s architectural heritage.”

Ms Tennant said there would be reduced rates for charities.

“We hope this inspires groups of people who do good works, often for little reward, to hold their meetings or fundraisers in the kind of place that would normally be beyond their budgets.”

Kate Galloway, co-founder of K & N Travel Associates, told us: “The Glen is a hidden treasure, yet so many people pass through the Borders unaware of what they are missing.