Hot air rises, but the hysteria that has enveloped the lower reaches of the UK housing market in the wake of the deepening crisis in the banking sector has so far failed to percolate through to the top. On the contrary, niche residential developers in the elite £3 million-plus trophy house market who previously plied their trade in gilded international enclaves within the M25, are now seeking and finding affluent home-grown buyers in other leafy corners of the inner Home Counties. Meanwhile, Simon Ashwell of Savills’ Weybridge office (01932 838000) has seen property values in exclusive St George’s Hill rise by a massive 25% this year alone, as Russian buyers continue to set the pace. ‘This is a largely male-dominated market-place, where the boys who make the buying decisions see their houses in much the same way as they see their cars nobody wants last year’s model.’

Size also matters. A buyer with Russian connections recently paid close to the £12m guide price for the imposing, 15,000sq ft Park Hill on St George’s Hill, and should a Russian buyer take on the 12-year-old, 8672sq ft Cullen House on Horseshoe Ridge, St George’s Hill, for about £4.5m, Mr Ashwell would expect to see the seven-bedroom mansion being the subject of a comprehensive make-over. In this fast-moving marketplace, some Russians come, and others go. The palatial, 15,358sq ft, neo-Regency Hartlands in Rodona Road, St George’s Hill, was completed 18 months ago to the exacting specifications prescribed by its Russian owner, but he never got around to moving in: the mansion is now back on the market with Savills and Curchods (01932 643322) at a guide price of £11.5m.

Surrey’s prestigious 750-acre Wentworth estate is also popular with buyers from eastern Europe, many of whom are educating their children here, and also have houses in central London. Ease of access is a major factor, and they like the convenience of being able to land their helicopters at Fairoaks airport near Chobham, five minutes from Wentworth, and their planes at Farnborough, 15 minutes away. Some 40% of all houses sold by Knight Frank this year for more than £10m were bought by Russians, James Crawford reveals, and he expects to see one of Wentworth’s most sumptuous properties going in the same direction. Built in 2005 to imperial standards of luxury, 17,000sq ft Hanover House at Wentworth has four opulent reception rooms, five bedroom suites, a second-floor penthouse suite with its own dining room, sitting room, kitchen, study and cinema, a swimming-pool complex and a tennis court the whole set in 2.3 acres of manicured grounds overlooking the 14th fairway. Knight Frank (020?7629 8171) and Hamptons International (01344 627555) quote a guide price of £15m.

Privacy and security are major concerns for buyers at this level, and Russians in particular, and those prepared to buy outside Surrey’s gilded gated communities like a house to be protected by a substantial acreage of land. Knight Frank recently found a Russian buyer for Castillian Developments’ 14,000sq ft Kingsmead with 30 acres at Frensham, Surrey, at a price ‘in excess of £10m’. Hampton Court-based Octagon Developments has been building trophy houses in prime areas of the stockbroker belt since the mid-1980s, and marketing director David Smith sees no reason to change the firm’s strategy. ‘Quite apart from the Russians, there’s no shortage of British buyers for houses in the £3m-plus price bracket; our problem is finding the right sites to build them on,’ says Mr Smith. As a result, the company has extended its operations to other areas favoured by affluent City commuters, such as Sevenoaks in Kent, the Chalfonts in Buckinghamshire, or even Sandbanks at Poole, Dorset. The recent sale of an Octagon house at Little Chalfont, to an English couple for £3.5m, has set a new benchmark for trophy-house prices in this sought-after greenbelt area.

Since the 1920s, the picture-postcard village of Chalfont St Giles has been a magnet for successful City businessmen, who built large family houses on the wooded slopes that encircle the village. Now these houses are gradually being replaced by a new generation of country houses built to 21st-century standards of luxury and energy efficiency. Mike Shearn of Berkshire-based Porchester Homes could hardly believe his luck when he beat off the competition to secure a 1920s house in tree-lined Mill Lane with three acres of grounds and panoramic rear views across the village to the surround-ing hills. Three years on, the original house has gone, and the finishing touches are being applied to two distinguished, state-of-the-art, but subtly different six-bedroom houses called Lutyens and The Mead each set in 1.5 acres of gardens. Both are for sale at £3.25m through Buckinghamshire agents The Frost Partnership (01494 872233).

* Search for all prime country houses for sale