The 31 Most Expensive Homes In Tech

Xanadu 2.0 Bill Gates houseBing MapsBill Gates lives in a futuristic home in Medina, Wash.

The tech titans have some fantastic toys: massive yachts, sleek cars, and over-the-top homes.

Microsoft co-founder Bill Gates’ home has a pool with an underwater sound system, Square CEO Jack Dorsey’s place has a 20-foot retractable glass roof, and Oracle CEO Larry Ellison has his own Hawaiian island.

We found the 31 most expensive homes in the U.S. owned by the kings and queens of tech.

#31 Steve Wozniak's original Apple abode

Estimated home value: $4.4 million

Title: Co-founder, Apple

The Apple co-founder's beautiful Los Gatos, Calif., home, originally constructed just for him in 1986, hit the market this spring for almost $US4.5 million, according to the New York Daily News. It's a six-bed, six-bath mega mansion of 7,500 square feet with gorgeous views of the Los Gatos Mountains, stained glass accents, and an outdoor pool with a cascading waterfall.

Wozniak's home may be almost 30 years old, but it had a major facelift in 2006, updating a lot of features but keeping the original contemporary designs.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#30 Marissa Mayer's Palo Alto place

Estimated home value: $5.3 million

Title: CEO, Yahoo

Another tech giant in Palo Alto, Marissa Mayer lives in a surprisingly modest home for someone of her stature. Her home, which was built in 2006, is worth about $US5.3 million, according to the Santa Clara County assessor's office. Mayer also has a $US5 million penthouse on the 38th floor of the Four Seasons in San Francisco.

It has five bedrooms, six and a half bathrooms, an outdoor patio, and large backyard. While her home may be comparatively smaller to some of her industry's peers, it makes a great setting for hosting events. In 2010, Mayer held a $US30,000-a-plate fundraising dinner at her home for Obama's campaign.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#29 Chris Hughes' renovated New York factory

Estimated home value: $US7 million

Title: Co-founder, Facebook; Editor-in-chief, The New Republic

One of the co-founders of Facebook and currently the Editor-in-chief of politics magazine The New Republic, Chris Hughes bought his place at 30 Crosby Street with his partner in 2010 for $US4.8 million, according to The Real Deal. It's a 4,164-square-foot, one-room loft divided by a row of wood columns with exposed brick walls and antique wood floors.

The 125-year-old building, which is known for having had some famous musician residents (Alicia Keys, Lenny Kravitz, Courtney Love) was formerly a corset factory, Nick Jabbour, Senior Vice President at Nest Seekers International, told us.

'Considering that Hughes likely reoutfitted and updated the space, his loft... is likely worth about $US7 million today,' Jabbour said. 'SoHo remains one of the hippest neighborhoods in New York and is wrought with converted condos that meld old industrial accents with super-modern conveniences.'

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#28 Leo Apotheker's California residence

Estimated home value: $7.1 million

Title: Former CEO, Hewlett-Packard

Apotheker, who succeeded Mark Hurd as the CEO of Hewlett-Packard, paid $US7 million for a house in the Silicon Valley suburb of Atherton in December 2010.

Though his tenure as CEO was short-lived, Apotheker received a $US4.6 million bonus to cover his moving expenses as he flew from Germany to California, which helped with the cost of his new home, according to SEC filings.

The house has six bedrooms as well as a pool, game room, and wood-paneled walls in the library. The San Mateo Assessor's office evaluates the home at $US7.1 million for the 2012 tax year.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#27 Mark Zuckerberg's Facebook home

Estimated home value: $7.3 million

Title: Founder and CEO, Facebook

Zuckerberg reportedly bought himself a $US7 million home in Menlo Park near Facebook's headquarters in 2011. In addition to five bedrooms and five bathrooms, the home also comes with a saltwater pool, a big sun room, and a huge porch and yard.
Today, Zuckerberg's home is worth an estimated $US7.3 million, according to the Santa Clara County Assessor.

Considering how much money Zuckerberg has, he could have spent a lot more on a place, though a brochure for the home originally advertised it as $1 million less than what he paid.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#26 Mark Hurd's Marymont Avenue mansion

Estimated home value: $8 million

Title: Co-president, Oracle

Hurd lives on Atherton, Calif.'s Marymont Avenue, in a 6,410-square-foot home with five bedrooms, six and a half bathrooms, and a large outdoor space.

He and his wife Paula purchased the home in 2005 for $US7.1 million, according to city records, and today the home is worth about $US8 million, based on data from the San Mateo County assessor's office for the 2012 tax year.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#25 Sheryl Sandberg and David Goldberg's 7,000+ square foot house

Estimated home value: $8.69 million

Title: Sandberg: COO, Facebook; Goldberg: CEO, SurveyMonkey

Sheryl Sandberg, Facebook's COO, and her husband David Goldberg, SurveyMonkey's CEO, also live in Atherton, in a 7,120-square-foot home with five bedrooms and eight and a half bathrooms. The couple bought the home for nearly $US8 million in 2004, at which time Sandberg was still an exec at Google.

According to the San Mateo County assessor's office, the Sandberg-Goldberg home is worth just shy of $US8.7 million, based on records from the 2012 tax year.

In February of last year, the Wall Street Journal reported that Sandberg and her family were building a large place in Menlo Park, near Facebook's offices, which will be a modern house of nearly 9,200 square feet. It's unclear whether or not the construction of the new home will result in selling the one in Atherton.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#24 Carol Bartz's Isabella Avenue home

Estimated home value: $8.7 million

Title: Former CEO, Yahoo

The former Yahoo CEO and her husband live in a simple-yet-stunning 2,000-square-foot home on Atherton, Calif.'s ritzy Isabella Avenue. They purchased the home, which sits on four acres, for $US4.6 million in 1995.

It has three bedrooms, two bathrooms, an outdoor pool, and a large roundabout driveway. If Bartz and her husband sold their home today, they would make a tidy profit, as the current value of the house according to the San Mateo County Assessor's office, is about $US8.7 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#23 Gideon Gartner's Manhattan penthouse

Estimated home value: $9.2 million

Title: Founder, Gartner Inc.

The founder of technology research firm Gartner, Inc. bought a $US9.15 million one-bedroom penthouse apartment in Manhattan's Metropolitan Tower Condominium on West 57th Street after selling his Millennium Tower penthouse last year. Its 3,000 square feet with limestone flooring and rosewood and silver finishes. The old apartment sold for a reported $US20.7 million.

'The 25-year-old Metropolitan Tower is facing a bit of a 'resetting of value' as Extell's One57, currently the tallest residential building in the Western Hemisphere, has topped out,' said Nick Jabbour, Senior Vice President at Nest Seekers International. 'One57 has partially obscured what were once some of the most stunning Central Park views in the city. This resulted in a bit of a sell-off of the units there.

Jabbour said that Gartner purchased after the building's superstructure had been started, but his apartment still has spectacular views to the east and south. He estimated that the value of the apartment has remained about the same since Gartner purchased it last year.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#22 Jack Dorsey's open sky dwelling

Estimated home value: $10.2 million

Title: Founder and CEO, Square; Founder, Twitter

In February of last year, Twitter founder Jack Dorsey bought a house on El Camino Del Mar in San Francisco for $US9.9 million. The list price was originally $US18 million before the price came way down. Even so, at $US9.9 million it would make it the most expensive two-bedroom house in San Francisco at that time. The San Francisco Assessor's office currently values the home at $US10.2 million.

The 3,700-square-foot home was built in 1965, and now has some extraordinary features like custom Brazilian wood cabinetry, picturesque views of the Golden Gate Bridge, and -- perhaps the most fantastic feature -- a 20-foot retractable glass roof that functions as an enormous sky light.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#21 Tom Proulx's Atherton estate

Estimated home value: $12.7 million

Title: Co-founder, Intuit; CEO, Netpulse

Proulx owns three neighbouring properties on 11 acres on Fletcher Drive in Atherton, Calif. A 1997 Businessweek article reported that Proulx has a nine-hole golf course in his backyard and a 'Jetsons-style 'smart house'' security system, according to the New York Times.

Proulx's three adjacent homes are valued each at $US6.1 million, $US4.5 million, and $US2.2 million, according to the San Mateo Assessor's office, bringing the combined value of the properties to about $US12.7 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#20 Sergey Brin's exquisite West Village apartment

Estimated home value: $13 million

Title: Co-founder, Google

The Google co-founder lives in a four-bedroom penthouse with a 23-foot balcony which he purchased in 2008 for $US8.5 million. One of the most extravagant features in the West Village apartment may be the limestone bath, which comes equipped with heated floors.

'With just five 'neighbours' in the building, and being the penthouse of a relatively new structure on one of the West Village's hottest blocks, Brin's apartment... is likely worth more than $US13 million,' said Nick Jabbour, Senior Vice President at Nest Seekers International. 'The tech industry has really embraced the West Village and Chelsea, and executives within the tech sector have taken a part in the skyrocketing values of these neighborhoods.'

Brin reportedly also owns a $US7 million property in Los Altos Hills, Calif.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#19 Larry Page's modest Palo Alto house

Estimated home value: $15.2 million

Title: Co-founder and CEO, Google

For being the CEO of one of the biggest and most valuable companies in the world, Page's home isn't as extravagant as some of the others on this list. His 8,000+ square foot home in Palo Alto sits at the end of a dead-end street. It has six bedrooms and six bathrooms. Page bought the place in 2005 for about $US7 million, and the value has now more than doubled, according to Curbed.

That's because Page built a second home on the same property, says Palo Alto Online -- an eco-friendly, 6,000-square-foot mansion, with an elevator, solar panels, a rooftop garden, and parking lot with pervious pavement.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#18 Gary Bloom's Isabella Avenue castle

Estimated home value: $15.5 million

Title: CEO, MarkLogic

The CEO of MarkLogic is a neighbour of Carol Bartz's, also living on Atherton's elite Isabella Avenue. His home, built in 2004, is 8,500 square feet with four bedrooms, four-and-a-half bathrooms, and a clean, manicured lawn. The San Mateo County Assessor's Office indicates the property is worth about $US15.5 million today.

Bloom was formerly the CEO and President of eMeter before becoming the CEO of big data company MarkLogic in May of last year.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#17 Elon Musk's ocean view villa

Estimated home value: $17 million

Title: Founder, Tesla, SpaceX

In January the founder of SpaceX and Tesla bought the Bel Air mansion he'd previously been renting for the past few years for a tidy sum of $US17 million.

The 20,000-square-foot home was recently remodeled, according to Curbed, and built in 1990. Featuring gorgeous city and ocean views, it was last listed in April for $US19.95 million before being snatched up by Musk for $US17 million. With seven bedrooms and nine bathrooms, Musk and each of his five sons could get their own rooms, plus one leftover for a lucky guest.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#16 Mark Cuban's massive Dallas palace

Estimated home value: $17.3 million

Title: Co-founder, Broadcast.com; Owner, Dallas Mavericks

Cuban built his giant home, the ninth most expensive in Dallas, in 1997. It gives him the perfect vantage point to attend the games of his basketball team, the Dallas Mavericks.

Cuban's massive home is worth about $US17.3 million, according to the Dallas Central Appraisal District office -- a major bargain for 24,000 square feet, 10 bedrooms, and 13 bathrooms.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#15 Mark and Alison Pincus' classic San Francisco home

Estimated home value: $17.7 million

Title: Mark: Co-founder and CEO, Zynga; Alison: Co-founder, One Kings Lane

Last year Mark Pincus and his wife Alison purchased a beautiful San Francisco home for $US16 million. The house is 11,500 square feet with seven bedrooms, six full bathrooms, and four half-bathrooms covering four stories. To get around the place, the Pincuses can use the stairs or the elevator. Other amenities include eight fireplaces and large picture windows with bay views. Zillow estimates the current worth of the home to be $US17.7 million.

Mark, who is the co-founder and CEO of Zynga, and Alison, who is the co-founder of online home goods curator One Kings Lane, aren't the only tech entrepreneurs in the neighbourhood -- their next door neighbour is Yammer founder David Sacks, who just bought his place in November.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#14 The Winklevoss twins' modern mansion

Estimated home value: $18 million

Title: Co-founders, ConnectU

The twins, who famously sued Mark Zuckerberg for allegedly stealing their idea for a college-based social network -- and were portrayed by Armie Hammer in the movie 'The Social Network' -- jointly purchased this contemporary 8,000-square-foot mansion in the Hollywood Hills last year for $US18 million.

The house comes with an outdoor pool and beautiful panoramic views of downtown Los Angeles. Tyler Winklevoss will be spending most of his time at their L.A. pad while Cameron runs the East Coast branch of Winklevoss Capital at their New York City HQ.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#13 David Sacks' new Billionaire's Row house

Estimated home value: $20 million

Title: Founder, Yammer (acquired by Microsoft)

The former COO of PayPal just bought himself an extravagant 17,500-square-foot home with a 6,000-square-foot guest cottage on San Francisco's 'Billionaire's Row' for $US20 million in November, according to Trulia. The home had originally been listed for an exorbitant $US65 million, and rumour has it that it will cost Sacks another $US10 million to finish and polish the place, which had been previously owned by Peter Sperling of University of Phoenix fame.

Sacks will fit right in on Billionaire's Row, as he sold his company, Yammer, to Microsoft for $US1.2 billion last year. The area is home to many other tech giants, including Larry Ellison and Mark Pincus.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#12 Ted Waitt's former L.A. Esquire residence

Estimated home value: $US21 million

Title: Co-founder, Gateway Computer

Gateway Computer co-founder Ted Waitt is the proud new owner of the former 2010 Esquire House in Los Angeles, according to the Real Estalker, which Waitt acquired for $US21 million from movie producer -- and Oracle CEO Larry Ellison's daughter -- Megan Ellison in an off-market deal.

The house is apparently a gated 'micro-compound' with four bedrooms, seven bathrooms, and unobstructed city views, with a curved wet bar in the living room and a state-of-the-art fitness center on the second floor.

Waitt picked up a near-11,500 square foot, six-bed Mediterranean mansion in Bel Air for $US14 million last summer, and reportedly sold it for $US16 million just 10 months later.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#11 Eric Schmidt's Spanish-style casa

Estimated home value: $21.3 million

Title: Executive Chairman, Google

The former Google CEO purchased his 7,000+ square foot home in Montecito, Calif., from comedian Ellen DeGeneres and actress Portia Di Rossi for a reported $US20 million in 2007. The Santa Barbara County assessor's office evaluates the property and improvements to be worth $US21.3 million for the current tax year.

With five bedrooms, four-and-a-half bathrooms, and a lush, green garden, it's the perfect setting for parties and weddings. And Schmidt regularly rents out the place for private events, like Kim Kardashian and Kris Humphries' wedding in 2011.

Schmidt also has homes in Nantucket, Atherton, and yes, on the water -- Schmidt is reportedly selling his lavish tugboat yacht for $US14 million as of this past April.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#10 Sean Parker's ivy-covered Manhattan townhouse

Estimated home value: $25 million

Title: Co-founder, Plaxo, Napster and Airtime; Founding President, Facebook

Parker is best known as the co-founder of Napster and an early Facebook supporter. He's the proud resident of a $US20 million, 7,500-square-foot West Village townhouse, which a broker named 'Bacchus House' after the Roman god of wine.

Covered in ivy with a historic carriage house, private garage, and landscaped atrium, Parker also enjoys luxuries like an indoor pool and astounding d├ęcor like graffiti art walls and subway-themed rooms.

Nick Jabbour, Senior Vice President at Nest Seekers International, said the West Village is still one of the most desired neighborhoods in the city. 'I would suggest that the property has appreciated a bit, perhaps just north of the $US25 million number, but the value has certainly remained intact at worst.'

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#9 Peter Thiel's Hawaiian shorefront getaway

Estimated home value: $25.1 million

Title: Co-founder, PayPal; investor and entrepreneur

Thiel made the biggest single-family real estate purchase in the history of Maui, the Wall Street Journal reported, with his $US27 million home on the island back in 2011. The 1.7-acre Makena property, which was never on the market, has a contemporary 4,500-square-foot tropical home and a pool.

Thiel also owns a home in San Francisco and, it's rumoured, in Los Angeles.

Today the Maui County assessor's office evaluates the land and home in Makena at around $US25.1 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#8 Jeff Bezos' Beverly Hills palace

Estimated home value: $26.7 million

Title: Founder and CEO, Amazon.com

With seven bedrooms and seven bathrooms on almost 12,000 square feet, Bezos lives like a king in his Beverly Hills home. Bezos and his family enjoy amenities like a pool, sunken tennis court, gym, greenhouse, and a separate guesthouse that spans more than two acres. And if he's looking to socialize, Bezos can wave hello to his neighbour, Tom Cruise.

According to the Los Angeles County assessor records, the property plus improvements totals $US26.7 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#7 Trevor Traina's new cliffside castle

Estimated home value: $US35 million

Title: Founder, CompareNet, DriverSide, IfOnly

Serial entrepreneur Trevor Traina and his wife Alexis bought a $US35 million home on San Francisco's 'Billionaire Row' in March, according to local real estate blog Socket Site. At this price, it makes it the most expensive home ever purchased in the city.

Traina's new home has six bedrooms, seven bathrooms, bay windows with bay views, a chef's kitchen, catering room, a 3,000 bottle wine cellar, and a heated outdoor spa and pool -- a rarity in San Francisco.

The home, designed in 1922 by famous San Francisco architect Frederick H. Meyer,
was last sold in late 2011 for $US29.5 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#6 Omid Kordestani's lavish 15 Central Park West pad

Estimated home value: $45 million

Title: Senior Advisor to the Office of the CEO and Founders at Google

Kordestani is known for being one of the original Googlers -- the 12th employee, to be exact -- and now an intimate advisor to the founders and CEO. He owns a swanky apartment in 15 Central Park West, one of the most elite buildings in New York City. His four-bedroom, six-and-a-half bath apartment is over 5,400 square feet, not including a 405 square-foot terrace. His next-door neighbour is Goldman Sachs CEO Lloyd Blankfein.

Kordestani bought his apartment in March 2008 for $US29.5 million. Nick Jabbour, Senior Vice President at Nest Seekers International, said that many of the large apartments at 15 CPW can go for $US7,000 to $US8,000 per square foot, and given that Kordestani enjoys a large terrace, '(it) does bump the desirability, and therefore the value... and I would suggest that, given reasonable evidence, the value is truly in the $US40-$50 million range. This is still a tidy bit of appreciation given his purchase price.'

Kordestani also owns a home in Atherton, Calif., another wealthy neighbourhood.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#5 Yuri Milner's Silicon Valley French Chateau

Estimated home value: $45.6 million

Title: Investor in Facebook, Zynga, Twitter, Spotify, ZocDoc, 360Buy.com, and Groupon

Milner, a Russian billionaire known for his investments in tech giants like Facebook, Twitter, and Zynga, bought a titan of a home in March 2011 for $US100 million, making it one of the most expensive home sales in the U.S., and it wasn't even on market when Milner bought it, according to The Wall Street Journal.

The home, a 30,000-square-foot French chateau, sits on 11 acres of prime Los Altos Hills real estate with views of the San Francisco Bay. In addition to five bedrooms and nine bathrooms, the home comes equipped with a ballroom, private theatre, wine cellar, and indoor swimming pool.

But then last year, the Santa Clara County assessor's office reported that Milner paid almost double what the estate was worth -- just $US50.3 million -- and this year public records valued the home at $US45.6 million. Fortunately Milner has money to spend.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#4 Michael Dell's Hawaiian 'Raptor Residence'

Estimated home value: $58.4 million

Title: Founder and CEO, Dell

Dell may spend most of his time at his contemporary home, 'The Castle,' in Austin, Tex., but he also owns a gorgeous tropical paradise in the gated community of Kukio, Hawaii, where he spends holidays.

'Raptor Residence,' as it's known, is a 18,500-square-foot, seven bedroom, seven-and-a-half-bath home situated on 189,704 square feet of prime waterfront land.
The County of Hawaii assessor's office valued the home at just over $US58 million for the 2013 tax year.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#3 Paul Allen's Mercer Island multi-mansion estate

Estimated home value: $US116.2 million

Title: Co-founder, Microsoft; Chairman, Vulcan

Microsoft co-founder Paul Allen owns homes in Malibu, New York, and St. Jean Cap-Ferrat, France, but perhaps the most magnificent of his estates is the one on Mercer Island, Washington, close to where he grew up. Allen owns not just one, but nine homes on eleven parcels of land on the island near Seattle, according to the King County Department of Assessments.

Allen mainly occupies one of the homes. The others are occupied by family members or reserved for guests. The homes come with some pretty fantastic features, including a floating helipad, an NBA regulation-sized basketball court, an enormous fitness center, a ballroom, a gorgeous swimming pool with a waterslide, and thousands of square feet of water frontage.

According to the King County public assessor records, Allen's Mercer Island properties are valued at $US38.9 million, $US26.7 million, $US21.3 million, $US20.2 million, $US2.8 million, $US1.8 million, $US1.5 million, $US1.2 million, $US847,000, $US650,000, and $US283,000, totalling about $US116.2 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

#2 Bill Gates' futuristic Xanadu 2.0

Estimated home value: $121 million

Title: Co-founder and Chairman, Microsoft

Gates is one of the most well-known tech moguls, so it's fitting that he has one of the biggest, techiest homes in the tech world. Nicknamed Xanadu 2.0, the Gates home in Medina, Wash., is 66,000 square feet with futuristic features like a pool with an underwater sound system, a 2,500-square-foot gym, a library and domed reading room, an Art Deco-style theatre, and heated floors.

U.S. News reported that guests wear computerized pins that the house can actually read, and then adjust music, lighting and climate settings to each guest's preference. The house reportedly took seven years to build and cost $US63 million. Based on King County public records from the 2012 tax year, Gates's property is valued at about $US121 million.

To estimate the approximate current value of the homes, we looked at recent sales and public assessors' records, and we spoke to expert realtors and appraisers in these homes' markets.

Now see the biggest homes of the fat cats in finance.

Follow Business Insider Australia on Facebook and Twitter

NOW WATCH: Tech Insider videos

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.