For more than 10 years, Sternlicht obsessed over every detail at Starwood. Now he’s counting on the same mania to help him build a second empire, as he launches three luxury hotel and condo brands aimed at the high-end customer: an ultra­exclusive line dubbed Crillon, a chain of eco-hotels named 1, and a casual-luxury fleet branded Baccarat (which will include the Wailea property).

The difference this time is that his competitors are copying his every move. In early summer, Marriott partnered with boutique-hotel pioneer Ian Schrager to launch a line of about 100 W-like hotels, and just about every hotel company is declaring itself green. Sternlicht also lacks the resources of Starwood, with its $12.4 billion market cap, let alone those of other giants such as the Four Seasons—owned by a consortium that includes Bill Gates and Saudi prince Alwaleed bin Talal bin Abdul Aziz al-Saud—and Hilton Hotels, which is being purchased by the Blackstone Group for $26 billion. Sternlicht is financing his new empire with debt and $3 billion raised over the past two years by his real estate private equity firm, Starwood Capital (which, despite the name, has no ties to the hotel company).

Sternlicht has always been one of the most paranoid people in business. But now, finally, the paranoia seems justified. And so he’s moving with a velocity that boggles the minds of those closest to him. “It’s insecurity—not necessarily in a negative way, but more like, ‘Holy shit, I’m falling behind here,’ ” says Jeff Dishner, Starwood Capital’s chief operating officer and an associate of Sternlicht’s for 16 years. “I thought when he was stepping down from Starwood Hotels, he’d want to slow things down. But he went in absolutely the opposite direction and accelerated. I’d probably say he’s more insatiable than he ever was.”

The most common description I heard about Sternlicht in the months I spent watching him construct his new hotel kingdom is that he uses both sides of his brain, moving seamlessly between building spreadsheets and evaluating bedsheets. “Barry is one of the few guys in private equity who understand brand value,” says Hamilton South, the former chief marketing officer of Polo Ralph Lauren, who now runs a marketing and consulting firm. “Most of them look at what something is worth based on the math. Barry can do that but also say ‘The math isn’t great, but this is a phenomenal brand. We’ll figure the math out.’ ”

Connecting these two hemispheres is a corpus callosum that seems to pulse with signals of being wronged; neither side feels it’s getting the proper respect. In Starwood’s early days, people didn’t believe Sternlicht could develop the cobbled-together brands, dismissing him as a deal guy. It drove him crazy. He was creative; he was an artist. Would a Wall Street guy ever have thought to brand a hotel mattress, as Sternlicht did with Westin’s Heavenly Bed? Then, as he became better known for his innovations, people doubted that he had the capacity to guide a company through the 2001 recession. “I mean,” he complained to me, “the papers were saying, ‘Can he manage through 9/11?’ You know, ‘This will prove his ability.’ But they didn’t say that I had done it after Starwood came out fine.”

With this latest venture, he’s melding the two sides right from the start and taking credit for every step of the process. The 1 is intended to be a sort of W with a conscience: “I was looking for something that would give us a soul,” Sternlicht says. “The W was for me when I was 35, and this is for me when I’m 45.” While Sternlicht owns a Lexus hybrid, he doesn’t exactly glow green. In addition to the Yukon, he gets around by Land Rover (“the cheap one,” he notes. “It gets great gas mileage”), a Mercedes AMG, and a Gulfstream IV. But he sees a growing market for urban green travel and is finding prime spots in city centers, creating a distinctive hotel for each. In Washington, he recently bought the Nigerian embassy, across the street from the Ritz-Carlton, for $15.5 million and plans to build something that Mies van der Rohe might have crafted if he’d been asked to draft a Biosphere 3 for Princeton’s campus: Ivy will cloak much of the first floor and creep up the side of an airy glass-and-steel structure; a hanging garden will appear to cleave the hotel.

When Miami architect Chad Oppenheim first presented his design for the Washington 1, it resembled a copper-coated radiator. Sternlicht’s people groaned at Oppenheim’s presentation, but the boss told the group he saw something in the plans: “Give me four days, and if I can’t make this work, you can pick someone else.” Then he laid out his vision to Oppenheim. The architect says Sternlicht’s input, while invaluable, really just helped him return to some of his initial ideas. But Sternlicht doesn’t quite see it that way and keeps telling me so. “I literally told Chad what we wanted to do,” he says.

The other brands Sternlicht is developing came to him through the $3.2 billion purchase of Groupe Taittinger and Société du Louvre that he engineered shortly after leaving Starwood. The French firms controlled, among other luxury properties, the crystal company Baccarat (and practically the entire French town it uses as a base); Taittinger Champagne; and chic fragrance line Annick Goutal.