We imagine that after a multi-year renovation of a historic townhouse, when all the contractors and designers have left, it gets pretty quiet in a giant six-story townhouse with just one person living there. Originally constructed as one of twin Federal-style townhouses built for the daughters of a shipping merchant, 81 Horatio Street was eventually subdivided into seven separate apartments. Over the last few years, however, current owner John de Neufville has employed everyone from Jack Beyer (of Beyer Blinder Belle) to Frederick Bland (chairman, Brooklyn Botanical Gardens) to transform the separate apartments into a giant bachelor pad from the wine cellar/screening room in the basement to the hot tub on the roof, according to The Wall Street Journal. The six-level townhouse is described as a combination of two triplexes. Maybe they started out calling it a sexplex, but were drawing the wrong crowd at open houses. The transformed address "contain six bedrooms, five full baths, two partial baths, two kitchens and six working fireplaces." That 7,000 square feet is more than enough for de Neufville, who at age 32 is too young to be rattling around a big old house by himself. He's selling the place for $20 million, and moving to the Upper East Side where he fell in love with a different apartment.