Exterior work is shaping up on The Benson, an 18-story condominium building at 1045 Madison Avenue in the Carnegie Hill section of the Upper East Side. Designed by Peter Pennoyer and developed by The Naftali Group, the 210-foot-tall structure will yield 16 residential units spread across 59,032 square feet, for an average of 3,700 square feet apiece, as well as 3,993 square feet of ground-floor retail. There will be three penthouses, and the majority of the homes will be full-floor layouts. The property is located between East 79th and East 80th Streets, a short walk from Central Park.