Hearst Tower ( New York City ) - Case Study

Hearst Tower is one the world newest skyscrapers, located in New York City. Over seventy years ago, Hearst Tower was first built with only six-stories high. This first building was commissioned by William Randolph Hearst and was built by architect Joseph Urban. It was completed in 1928 with a total cost of $2 millions. In 2001, the plans of the new tower addition took place, and the new Hearst Tower with 46 stories tall was finished in 2006 after three years of construction. The building is 182 meters in height, and it consists a total of 200 Hearst employees.
This new Hearst Tower was designed by architect Norman Foster together with Gensler and Partners. They worked as a team to incorporate green design and put forward a sustainable design for Hearst Tower. The new building is also distinctive in environmental terms. It is the first new occupied office building in New York City that have been given a gold rating under the US Green Buildings Council's leadership in Energy and Environmental Design (LEED) program. Also, in 2006, as being the best skyscraper in the world completed in the year, Hearst Tower was awarded with Emporis Skyscraper Award.

Steel is the main source of the building. The need for the building triangular pattern requires approximate to 10,000 tons of steel, and almost 90% of the steel is recycled. The Histar steel sections are used in the wind bracing and gravity load system. All the columns are slating inwards and outwards alternately. They are visible in the facade as diagonal lines over all faces of the skyscraper. These structural parts are inclined and function as bracing and column at the same time. This feature is called a diagrid design. For each of the triangular sections, four floors are accommodated. With every of these four floors, the columns changes their directions. The only connection between the floors and the columns is the tie at their edges. This way, the building leaves no lead bearing walls or column in their spans, and the interior of the building can be changed without any damages to the building structure.

Hearst Tower's steel structure

Beside steel, the entire building is covered with glass. These glass wall coverings allow the building internal spaces absorb a large amount of natural light. The glass also have a chemical coating (Low-E) that help to reduce solar radiation and prevent sun heat from entering the building, which a concrete or aluminum clad structure usually absorbs. This reduces about 25% in the total air conditioning costs of the building.

Glass windows of the entire building

The atrium floor is covered with heat conductive limestone. Limestone is a very important material. This limestone atrium floor of the Hearst Tower has a tubing network of polyethylene underneath. It helps to circulate water for cooling in the summer and heating in the winter.

The limestone atrium floor

The Icefall (about two-stories high) runs through a three-story water sculpture. With the built of thousand of glass panels, this waterfall collects rainwater that cooling down the ten-stories atrium in the summer and warming it in the winter time.

Three-story water sculpture - Icefall

The building was built with a roof that absorbs rainwater in a 14,000 gal basement reclamation tank. This collection of rainwater would later replace the lost water due to the evaporation in the office air conditioning system. This storing water helps to irrigate plantings and trees inside and outside the building and fulfills the need of water sculpture for the main lobby.
The entire walls of the building are coated with low-vapour paints. These low-vapour paints helps to resist the damage of the water and prevents the growing of mold. With the low-vapour paints, very little of the moisture would get into the walls and move through the building materials.
Most of the furniture, finishes, and carpet have low-toxicity. Low- toxicity furniture and carpet are made without harmful chemicals that can off-gas in the building, which will help to improve indoor air quality and get healthier feelings.
Similar with the furniture and carpet, the concrete surfaces are also treated with low-toxicity sealants. This treatment goes without any chemicals that are harmful to the surrounding environment. With this low-toxicity consideration, the building is considered as a green design.

Complementing with the water element in the atrium, a fesco painting is installed by artist Richard Long. The painting is called the Riverlines. Riverlines is a rich, contemplative mural set against the elegant grey stones of the elevator core. This art piece resembles a type of Stone A cave painting for the 21st century. With the image of a river, it represents a symbol of journey (a journey of life).

Riverlines by Richard Long

The building is installed motion sensors that control artificial light according on the amount of the natural light. Therefore, the sensors also are used to turn off the lights and computers when the area is left empty.


Preferences:

http://www.greenquest.co.uk/greenhome.html

http://www.flickr.com/photos/28488028@N06/4008123448/

http://www.international-highrise-award.com/en/presse081.html

http://www.archinomy.com/case-studies/287/hearst-tower-in-new-york-city

http://www.nyc-architecture.com/MID/MID124.htm

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