If you’re someone who appreciates homes with ingenious, space-saving features, we highly encourage you to check out Colin Cowie’s Flatiron penthouse, which is on the market for $5,750,000. The wedding guru/event planner/interior designer, who currently hosts Lifetime’s Get Married, purchased the top two floors of The Emory building in 2007, pre-construction. He then created a 3,000-square-foot duplex filled with thoughtful customizations, from an expandable kitchen countertop to lots of hidden storage to an informal dining room that converts into a formal dining room (for more on that, see our photo gallery). The unit comes with two bedrooms (one of which is currently used as an office), two-and-a-half baths, a key-locked elevator, plus 900 square feet of private rooftop terrace. The listing is held by Emily and Elizabeth Beare at CORE Group.