Tower 4

In designing 150 Greenwich Street, Maki and Associates took a two–fold approach – creating a "minimalist" tower that would assume an understated, reverent position opposite the memorial while developing a more active podium intended to foster interaction with the immediate urban environment at pedestrian street level, bringing energy and vitality as part of the overall downtown redevelopment effort.

The building's façades will be clad in floor–to–ceiling windows utilizing composite glass with multiple layers of coatings intended to achieve a mat metallic quality with a luminous sheen. This will give the tower an abstract quality – minimal, light, cool in color, and ephemeral, changing with the light of day. Seen from a distance, the tower will possess a unique angular profile that is chiselled at its crown, assuming position amid the spiral composition proscribed for Towers 1 through 4 under the master plan for the site.

The two glass obtuse edges of the tower on the southwest and northeast corners will be articulated with dramatic indentations, making them appear slender and sharp. Inside, a single edge will form two corners with a window from the open office to allow for uninterrupted views at the corner tip of the floor.

The office lobby, with a 47–foot ceiling, will face Greenwich Street and feature three entrances – one each on Cortlandt, Liberty, and Greenwich Streets. The lobby will be symmetrical in its composition and will offer panoramic views of the WTC site. The inner core wall of the lobby is clad in polished black granite to mirror the Memorial inside and is rotated to realign the geometry of the space so that it is parallel to the park. The walls of the elevator banks are finished in fused oak and glass panels to echo the oak trees lining the Memorial Park.

On the tower's Church Street side there will be a 75–foot atrium that will offer up a dynamic new urban experience, amalgamating the transit hall of the new WTC Transportation Hub with the WTC's retail elements to form a single, identifiable whole featuring multiple floors cascading to the street, enlivening the area and becoming a symbolic feature of a revitalized WTC. The atrium space will weaves its way into the base of the tower to provide retail space and perhaps a restaurant that faces the memorial park.

The four corners of the building site lie at varying topographical elevations, resulting in a 12–foot difference from the high point on the corner of Church and Cortlandt Streets to the lowest point on the corner of Greenwich and Liberty Streets, diagonally across the site. As a result, the street fronts of the building at ground level on all four sides will be on an incline, and the interior levels all will need to mitigate the differences to achieve comfortable entry points as well as harmonious spatial relationships with the surrounding pedestrian environment.

The podium of the building, from floors 1 to 3, will be designed to respond to character inherent in each of the streets and to further enrich the pedestrian experience. The building will be set back from all corners, creating an expanded public area along the sidewalk in the form of a small entry plaza. Each corner will provide either an entrance to the office lobby or access to retail and the transit hall.