Architect Michael B. Lehrer says the project's master stroke is the west-facing aluminum and glass tower. It enlivens the modern facade of the six-unit building while also controlling natural light and ventilation. "On the ground floor of a typical unit, it would be dark," he says. "But here all the light is captured and you experience it on all floors." The tower acts as a thermal chimney, pulling hot air from the four floors and forcing it out through operable doors.