4000 North Fairfax is a 330-unit, 22-story tower at the edge of the Ballston corridor in Arlington, Virginia. The tower exemplifies our approach to design, in that it avoids the obvious solution for a site-specific approach that elevates the entire project. A typical development would result in an L-shaped scheme. Alternatively, our scheme is composed of three narrow bars of varying height. The result is a skyline that stands out against the existing residential towers, a plan that maximizes outside corners for better unit visibility, and a slender and vertical end profile visible from each direction along Fairfax Drive. At the ground, the sliding tower creates a small urban plaza ringed by retail. Varying tower heights provide two levels of outdoor amenities, including a southerly exposed pool. The center tower is tallest incorporating a two-story clubroom and penthouse with unobstructed views to north.