We are pleased to present this book which showcases ... - WSP Group

Sister companies Flack + Kurtz and WSP Cantor Seinuk are
collaborating on the design of Hearst Tower, a 46-storey glass and
steel skyscraper rising from the six-storey base of a landmark art
deco building in Manhattan.
The original masonry facade building, completed in 1928, was
commissioned by the magazine owner William Randolph Hearst as
the first stage of a corporate headquarters for his vast publishing
empire. Designed by Joseph Urban and George P Post & Sons, the
building was intended to accommodate nine additional floors which
were never built.With its limestone facade featuring columns and
allegorical figures representing music, art, commerce and industry, the
building was considered an “important monument in the architectural
heritage of New York”, and was designated as a Landmark Site by the
Landmarks Preservation Commission in 1988.
In early 2001, the Hearst Organisation commissioned the British
architect Lord Foster, selected for his partnership’s experience in
high-rise buildings and its track record with historic structures, to
design a new headquarters on the site of its existing building.
A major design requirement was the preservation of the six storey
landmark facade and its incorporation into the new tower design.
The new design incorporates two underground levels and a sevenstorey
high interior atrium, formed by a horizontal skylight system
spanning approximately 12 m from the tower columns to the existing
facade.The tower has two distinct zones, with the office zone
starting at 35 m above street level from the 10th to the 46th floors.
Below, the building houses the sky-lit lobby atrium, an auditorium,
a cafeteria and gathering and event/exhibition spaces.
Client:
The Hearst Corporation
Project team:
Architect: Foster and Partners
Associate Architect:Adamson Associates
Construction Manager:Turner Construction Co
Vertical Transportation:VDA
Lighting: George Sexton
Development Manager:Tishman Speyer Properties
Project value:
£285M
Project size:
182 m, 46-storey tower
80 000 sq m
Status:
February 2005: Steel erection topped out
June 2006: Completion scheduled
WSP services:
WSP Cantor Seinuk: Structural engineering
Flack + Kurtz: Building services
Fire protection
IT infrastructure design
Commissioning services
Structural design by WSP Cantor Seinuk
Landmark facade
Apart from the facade on three exterior faces of the building, all
existing construction was removed. New foundations for the tower
were positioned behind the facade, which is supported by its original
perimeter steel columns and spandrel beams and a new additional
grid of vertical and horizontal framing.A horizontal skylight system
connects the tower to the existing facade.
Structure
The building utilises a composite steel and concrete floor with
12 m interior column-free spans for open offices. On three sides,
the building is open to the streets, but on the west side it stands
close to a neighbouring high rise building.The services core zone
has therefore been placed asymmetrically on the west side of the
tower, but this reduces the structural benefit of utilising the core
as the main spine of the tower.To increase stability, the design
team developed a diagrid system, wrapped around all four faces
of the tower.
Diagrid
The diagrid system gives the tower its distinctive faceted appearance,
with tiers of interlocking triangles in stainless steel and glass resolving
into larger diamond patterns.The nodes at the intersection of the
diagonal and horizontal elements are a key element both of the
structural system and the architectural impact of the building.
Structurally, they are acting as hubs for redirecting the member
forces.Architecturally, they are required to be not larger than the
width of the diagrid elements in order to maintain the pure
appearance.The inherent lateral stiffness and strength of the diagrid
provides a significant advantage for the general stability requirement
for the tower under gravity, wind and seismic loading.This results in
a highly efficient structural system that consumes 20% less steel than
conventional moment frame structures.
Building services design by Flack + Kurtz
The Hearst Headquarters will be one of the first commercial office
tower buildings in New York to be awarded LEED® Gold
certification by the United States Green Building Council.
■ The energy efficient, environmentally sustainable and green design
features include:
– High performance glazing which does not sacrifice the visible
light transmittance
– High efficiency chillers and motors
– Variable speed drives
– Natural ventilation airside economizer
– Variable air volume system
– High efficiency filters
– Daylighting controls
– Energy efficiency controls
– Water side economizer
■ An innovative and efficient system has been developed for the
Grand Lobby space, reducing overall energy consumption through
the recycling of the tower spill air (cleaning and conditioning air
normally discharged to outdoors) to condition the space, including
cooling, heating and dehumidification;
■ The space between an apartment building adjacent to the project
is used to move air;
■ Central air handling units are located on the 18th floor,
as opposed to mechanical rooms located on each floor;
■ Temperature controlled from stations located on each floor;
■ Rainwater is collected and re-used for irrigation, cooling tower
make-up and water feature make-up;
■ Daylight sensors control lighting to reduce overall energy use;
■ This is the first building of its type using radiant floors for cooling
and heating.
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