The house was directly inspired by the broken grids and warped cubes of European modern artist Victor Vasarely."From the start I wanted to do a modern house, almost in the Bauhaus style," said Mr Simonyi. "Something that is ageless, rather than carrying the stamp of a particular decade." Described as an amiable bachelor, born, like Mr Vasarely, in Hungary, Mr Simonyi is a graduate of the prestigious Californian universities of Stanford and Berkeley. There's a whole phone and entertainment console in the toilet. You could spend your day there."Mr Simonyi, unlike many wealthy men, is generous with his time and his home. It is hardly fair to report, therefore, that there was not just one telephone and mini television monitor in his bathroom, but two of each, apparently for watching stock quotes And in the magazine rack, one old copy of Satellite Times. "It has a bed that rotates, and a place by the pool for rock bands to come and play, and he collects the work of a Hungarian abstract painter. Typically wired for high-speed Internet links, the houses run the risk of becoming introverted and cold.

Mr Gates began his house as a bachelor, but his new wife Melinda, expecting their first child, has reportedly hired a New York designer to lighten the place up."James Bond Modern" was how a sceptical architect friend in Seattle described the Villa Simonyi, after her own tour. "We can locate buttons in rooms that will let you talk to any light anywhere in the house," boasted an engineer with Lutron Electronics, one of the main suppliers for the Gates Home and other hi- tech houses. Usually they want to know "what can we do that's really unique, how does mine become more special than something else?" he said.They naturally lean to the latest toys, like touch-screen or voice-activated systems to dim the lights at the dinner hour, or conjure televisions out of marble sideboards. At night, furniture on a rotating platform 20 ft in diameter will turn away from the real beach - which the house faces - towards the grotto, spotlighted and safe.Mr Jeanette and other architects say that clients from the computer industry typically have an acute understanding of three-dimensional space.

Working with one software company client who did not wish to be identified, Los Angeles architect Brion Jeanette is putting the finishing touches to a home design with a curving concrete and metal roof whose lines are inspired by a Mercedes 300 SL Goldwing The car is one of 25 in the collection of his client. The house is planned to include a bowling alley, a 1950s- style diner, a mini-theatre, and an artificial beach grotto of 8,000 sq ft. Reagan-era cuts in top tax brackets from 70 to 28 per cent have left the rich richer than at any time since the Second World War. Beverly Hills 90210 mega-producer Aaron Spelling is now building the biggest single family home in California, 65,000 sq ft with 130 rooms.In the so-called techno-baronial homes, there is no single style. In 1920s Los Angeles the Doheny oil dynasty built the 48,000 sq ft Greystone Mansion, now owned by the city of Beverly Hills. Mr Simonyi's lakeside home in Medina, near Seattle, is less than a mile away.Others seized, as The New York Times observed, with "la manie de batir" - the fever to build - include Microsoft co-founder Paul Allen, Oracle Corporation founder Lawrence Ellison, and Apple co-founder Mike Markkula.The length of one's drive was a traditional measure of class for American gentry, but the size of a house is a critical status symbol. At the Gates House, they are given electronic badges which light their way along a reception hall lined with 40-inch video monitors, and computer systems memorise and store their tastes in lighting and music.

The most famous, Microsoft founder Bill Gates, is building a 45,000 sq ft, partly subterranean complex on the shores of Lake Washington (a standard family home is about 3,000 sq ft, and Hearst's was 49,000 sq ft), of concrete crossed with beams of fir logs recycled from old barns.At San Simeon, close to the Pacific between Los Angeles and San Francisco, arriving guests were assigned a personal valet or maid for the length of their stay. Yet for all his evident pride in the building and his client, Microsoft programming wizard Charles Simonyi, he seems a little astonished by them both. William Randolph Hearst emptied whole castles and monasteries to furnish his 38-bedroom Californian hilltop palace at San Simeon, with its Gothic dining room, Roman statuary, and vaguely Spanish renaissance architecture. Xanadu, as it was called in the film Citizen Kane, spoke volumes about the man born to a $400m silver fortune who wanted to own people and things, even the presidency."It was almost as if Hearst sub-consciously realised that his newspapers were trashy, his political life a failure, even his motion pictures not entirely successful," wrote his biographer WA Swanberg, "and he was determined in San Simeon, if nothing else, he would leave an enduring monument to his greatness."Nearly 50 years after Hearst's death, the stately homes of America's newest aristocracy are rising in the suburbs of Silicon Valley and the outskirts of Seattle, Washington, a city famous for its cappuccino, grunge rock and rain, and a certain classless, rugged attitude.The fortysomething nerds who've made fortunes in the high technology trade are building their own monuments, and filling them with techie toys. The Villa Simonyi, eight years and $10m in the making, stands as his biggest assignment. Mr Lovett has been practising architecture since 1948 around Seattle, Washington, and is one of its leading modern architects.