They did so by bringing new sources of income into the estate, by hosting everything from yoga events to chilli festivals, from marathons to weddings and even philosophy conferences. To heat the huge number of draughty rooms, they installed a ground-source heating system, which required several miles of underground pipework.
At the same time, with help from Natural England, they dredged the lake, replanted avenues of trees and repaired some of the crumbling lodges and bridges around the estate.
No wonder, then, that they have been named joint winners in the country house restoration section of this year’s Georgian Group Architectural Awards.
These awards are in their 12th year, and include as many celebrated presenters (the Dukes of Kent and Gloucester, Viscount Linley) as winners (the Duke of Bedford, Sir Andrew Lloyd Webber). No surprise, then, that the award sponsors are the equally upmarket estate agents Savills.
“Georgian houses are still the most popular, ” says Crispin Holborow, director of Savills’ country house department, and one of the awards judges. “Almost invariably, the properties are roomy, have good volume and great spaces. The architects used the tenets of proportion and classical style, and very often sited the houses in the middle of lovely landscape.
“This was an era in which there was such an explosion of activity; a period during which so much was happening in painting, architecture and the arts.” Something well known, of course, to Robert Bargery, the secretary of the Georgian Group. For the organisation not only promotes the aesthetic and architectural virtues of the period from 1700 to 1840, but also runs an estate agency wing that specialises in the sale of Georgian properties.
Why is it, then, that houses of this period have remained so popular with the property-buying public?
“In terms of proportion and symmetry, the spaciousness and the geometry of the interior correspond with the facade, ” he says. “At the same time, the houses are built on a human scale, with materials that acquire a certain patina as the years go by.
“Not only that, but they hold their value and remain a good investment. In property terms, they represent a virtuous circle.”
And it’s not just the asking price that Bargery and his colleagues want prospective house buyers to come up with, but a certain enthusiasm, even reverence for the style.
It’s not just in the prosperous parts of the Home Counties that they have places for sale, but in locations such as Sheerness, Wisbech and even Deptford in southeast London.
“One thing we do try to ensure is that the right people live in these houses, ” he says. “We attempt, when selling these properties, to ensure that the people who buy them will not just look after, but cherish them.”
Not quite the attitude you encounter from the average high-street estate agent, who is more concerned that your mortgage is in the right place, rather than your heart. Then again, a Georgian house isn’t just a home, it’s a piece of living history.
What’s more, it’s history that is repeating itself. One of the categories in this year’s awards is for new houses built in the Georgian style. This may be 2014, but this year’s awards include two houses that owe their look to what was fashionable three centuries ago. One is Chitcombe House, at Woolland, in Dorset, which is reached by a set of curved steps arriving at a grandly pedimented front door. The other is Crucis Park, at Ampney Crucis, in Gloucestershire, which looks like it was built in the 18th century, yet replaces an earlier house that was constructed in the Sixties.
No question about it, then, Georgian is the architectural style that has arrived and never quite gone away. Even when faced with a leaking ruin that had been unlived-in for half a century, the current Lord Shaftesbury didn’t have the heart to turn his back on the ancestral home.
“A lot of people might see this house as a burden, ” he says. “Yes, it is a responsibility, but at the same time it gives me a sense of purpose to try and follow in the footsteps of previous family members.”
He’s got quite a lot to live up to, as well. The statue in Piccadilly Circus, known as Eros, but actually embodying the Angel of Christian Charity, was erected in memory of his philanthropic Victorian ancestor, Anthony Ashley-Cooper, the seventh Earl of Shaftesbury.
Mind you, he acknowledges that it helped him to have lived abroad for a few years, and built up a career as a DJ in New York.
“Because I had lived a free life, I didn’t have that feeling that my destiny had been controlled from birth, and that inevitably I would one day have the responsibility of running this estate, ” he says. “It meant I was able to reach a more rational decision about deciding to try and make things work here.