Very few VIPs landing at McCarran Airport are fortunate enough to be chauffeured to Las Vegas’ west side for a getaway even the wealthiest high roller can’t buy. Enter through the stacked ledger-stone security gate to the top of Spanish Hills, where Andre Agassi resides, and you are met with a cluster of ultra-luxurious custom homes—all 8,000 to 20,000 square feet that sit high above every other house in the city. But the largest is this 22,000-square-foot high-tech haven, topped with a flat slate-sloping roof, that international businessman Gene Yamagata has built for his family, friends and legions of business associates.

Born and raised in southern Idaho, 67-year-old Yamagata has owned and operated various Japan-based business ventures; today he owns several American companies, including a few airlines. His friendships span the globe, so in order to stay in touch he often hosts guests from Japan and elsewhere, 30 to 40 of them, sometimes for a week at a time. Much of his business life is transacted in his home.

Weather permitting, Yamagata lights his stone barbecue during the honored guests’ stay for a cookout on his wide patio overlooking the valley. Guests may plunge into the swimming pool or the elevated Jacuzzi, or gather around the fire pit, a perfect site for after-dinner cordials and conversation.

The Yamagata home adventure commences in the wide-open, sweeping foyer that graciously introduces guests to a new perspective of the Las Vegas Strip—a view that stretches from the Mandalay Bay hotel to the Bellagio. To the right is a dramatic waterfall “sculpture,” as well as a selection of treasured gifts and world collectibles displayed in lighted art cabinets adjacent to the dining room. The graceful, floating spiral staircase of mahogany and maple leads to the capacious second-floor “loft,” which houses the master suite, a mini master suite and a cozy relaxation room for reading and admiring the view. Swirling above is a sleek, custom-designed soffit and cove ceiling treatment, a design element echoed throughout the house.

Architect Mark Johnson, working with custom builder Paul Trudeau of Hilltop Development LLC, both in Las Vegas, designed the home’s main living spaces to open up to that vista, using, as his client requested, expansive view windows free of columns that would obstruct the panorama. The ingenious ceiling designs that punctuate the architecture, and conceal mechanical and duct work, are a Johnson/Trudeau team signature. Rooms throughout the home boast elements of the most sumptuous traditional spaces, but are interpreted with clean-lined sophistication and architectural curves. Las Vegas interior designer Joy Bell warmed this contemporary environment with first-class appointments, including unusual flooring. Bell uses, for instance, crocodile-embossed leather in the study, and Crema Marfil marble, with abstract pieces of black granite inlaid with red travertine and brass, throughout the main level.

Each of the main floor’s four guest suites is orchestrated with individual subdued color schemes and natural stone. One room is designed to accommodate a handicapped friend who visits annually; the space includes wheelchair-accessible doors, ramps, an elevator, shower and a private pool entrance.

After luxuriating in the hot tub or relaxing on the back patio with a beverage in hand, guests will want to check out the entertainment possibilities of the home, starting in the richly appointed home theater on the main floor, which seats up to 24 people. But believe it or not, it’s not all fun and games in the theater. “Using the Internet, you can do a video conference here with a company in Japan,” Trudeau says.

Two levels down, accessible via a leather-walled elevator, is a game room with a leather-lined pool table and four “judging” chairs that overlook the racquetball court on the lower level, which has an automated drop-down basketball backboard for hoop fans. For those who prefer greens over hoops, the lower level houses a three-hole putting green and a golf simulator that replicates every major course in the world, from Pebble Beach to St. Andrews in Scotland. “While you play, you are seeing digitized pictures taken at a famous course,” Trudeau says. “If you would shank the ball at Pebble Beach, you would shank it the same way on the simulator.”

As with any custom-built luxury home, the biggest challenge was meeting the client’s lofty expectations, which included a 3,500-square-foot garage for his dozen or so cars. The only real answer was to go four levels, Johnson and Trudeau agreed; the two professionals will partner in the near future on three other homes for Yamagata.

“This home is much larger than anything I’ve built,” the homeowner says. “It’s also the most advanced, with the latest touchscreen technology and [computerization]. It can be electronically monitored, and should a malfunction in any system occur, it can be pinpointed before a service technician shows up at the door to repair or replace a part.”

Technologies the homeowner never enjoyed before include the built-in AMX touchscreen that controls most everything, from temperature to lighting, security cameras and even television and audio operation. Even though a competent staff is a necessity with a house of this size, Yamagata can operate the touchscreen system himself. “It’s very self-explanatory and easy to use,” he says.

The $15-million project took two years to complete. “It’s the best home of that value in Las Vegas,” Trudeau says. “And it’s state of the art when it comes to automation.” The residence boasts 900 lighting fixtures, 110 switch locations, 70 automated draperies and blinds, three home audio systems and 16 interior cameras so he can monitor every room. The homeowner’s bedroom has a separate system that allows him to monitor the entire house, as well.

“When you have a house of this grandeur, you need automated controls,” Trudeau says. “It’s programmed so he barely has to lift a finger. One button can turn it all on when you arrive home—and all off when you leave.”

With all of Yamagata’s world travels, it’s quite possible, however, that “resort life” is wearing him out a bit. He recently married and is now building a house next door, where he says he will probably move. It may be a tad smaller, but you can be sure it will be just as high tech.