If you’ve got 14-foot-tall ceilings in your apartment, you may as well take advantage of them. This architect-designed co-op at 423 Atlantic Avenue, in Boerum Hill, utilized its soaring ceilings in unique ways. The apartment boasts a floor-to-ceiling library with custom shelves that span nearly 30 feet. It’s accessed by a steel-construction mezzanine built into the space. If you’re a fan of such quirky details (or at least own a lot of books), you’ll be happy to know the one-of-a-kind pad has just hit the market for $1.695 million.