One Madison Park is situated in a unique location on the Manhattan grid, fronting on East 23rd Street, a busy cross town thoroughfare—and at the foot of Madison Avenue, a major north–south thoroughfare that begins at 23rd Street, directly to the north. The tower acts as an axial icon on Madison Avenue, making the tower visible from great distances at the street level. The architectural challenge was to create a modern form that was respectful to the context of the Madison Square Park neighborhood while creating a visual dialogue with the adjacent historical high-rise building such as the Flatiron Building (1902) and the facing Met Life Tower (1909).

In order to allow construction to begin before the site could be entirely cleared it was decided that a portion of the tower would have to cantilever over an existing three-story building adjacent to the tower on its eastern side. The design team seized upon this idea to give the tower its unique configuration. From the main square mast of the tower clad in dark bronze glass, another shaft clad in white and clear glass is partially inserted and cantilevered from the main shaft in blocks ranging from four to six stories. The spaces between these blocks allowed for full floor residences with terraces built out onto the roof of the block below, that wrap around the north and east sides of the apartment.

The tower sits on a five-story base that holds commercial and service uses on the ground floor. Above the first floor, the base incorporates the main mechanical spaces and two levels of amenity spaces for the residents, which includes a fitness center, indoor pool, spa, and a private lounge with a terrace overlooking Madison Park.

Due to the placement of the tower in the middle of the site, each side could have windows opening to expansive views. Lateral bracing usually located around the perimeter was instead placed in the center, forming a cruciform of shear walls, buried between rooms and shafts minimizing the impact to room layouts. This integration of efficient space planning and structure gives each room within the homes an open expansive feeling focused on the city views beyond. High efficiency glazing was incorporated into the exterior skin to reduce solar heat gain with automated solar shading in each living room. An abundance of natural light is brought into every space of the tower which helps to minimize the need for artificial lighting. Due to its perimeter location, even the elevator lobby on every floor has a south facing window to bring in light and views.

The building’s footprint is 15.25m x 16.15m (50ft x 53ft) and is described as a slender tower with a height-to-width ratio of 12:1. Therefore, the lateral wind and seismic force-resisting system was the major engineering challenge. Naturally the shear wall stiffness and strength had to be maximized for this slender building while supporting the architectural design. This has been achieved by a combination of optimizing the configuration of the shear walls and using high performance concrete.

Due to its high slenderness ratio, the building’s lateral dynamic movement is mitigated by the design and the incorporation of a Tuned Liquid Damping System to reduce the acceleration of building motions. The system is comprised of three cast-in-place reinforced concrete tanks filled with water and incorporated into the building structure at roof level. More specifically the tanks are known as Tuned Liquid Column Dampers which are U-shaped to maximize their effect while occupying less floor area. The dampers were designed to provide approximately 3% additional damping to the building, and reduce the building accelerations to acceptable levels.