The Burj al Taqa (Energy tower) – Dubai – Under design
Without a doubt, the most innovative skyscrapers are or will be built within the next years in the United Arab Emirates, the place with the most impressive residential boom in the last decades. So, it comes as no surprise that Arab tycoons have included amongst their numerous other plans the construction of the “greenest” buildings. In Dubai, the 68-story skyscraper, due to be built, will be the highest building with zero gas emissions if everything goes according to plan. In order for this to happen, the design entails a series of measures: at the top of the tower, a huge, torch-like, 60-meter high wind turbine will be installed. Next, to the tower, an artificial island of 50,000 square meters will be constructed, covered with solar panels. This, in turn, will also supply Burj al Taqa with energy. Finally, the sea water will feed the tower’s air-conditioning system to cool its tenants in the high temperatures of the Arabian Peninsula.
The Hearst Tower – New York City – Completed – 2006
Hearst Tower is a very special building for New Yorkers, as it is the first skyscraper that was erected after 9/11. That’s not all there is to it–the tower was New York’s first “green” building. Up to 80 percent of the frame comes from recycled steel; whereas apart from its aesthetic impact, the building’s diamond shape is contributed to the use of even less steel, compared to the conventional rectangular skyscrapers. Polyethylene water pipes run along the floors and provide cooling or heating, depending on the season. As much as 50 percent of the water used by tenants comes from a huge underground reservoir where harvested rainwater is stored. In total, Hearst Tower energy needs are 25 percent lower than the maximum environmental limits laid down by the city of New York.
The Bahrain World Trade Centre Towers – Kingdom of Bahrain- completed in 2008
This 240-meter high, sail-shape complex dwarfs the skyline above King Faisal Avenue in Manama, offering unlimited views of the Persian Gulf. The two buildings comprising the complex resemble boat sails and are connected with each other via three bridges equipped with the same number of wind turbines-each turbine being 29 meters wide. The shape of the building ensures a steady flow of air to the wind turbines even when winds blow from a 45o angle. The three turbines are expected to generate 1.1-1.3MW of electric power per year, thus covering about 15 percent of the tower’s total energy needs.
340 on the Park – Chicago
The construction works that were completed in 2007 gave Chicago its first truly “green” building. It is a 62-story edifice with 344 apartments that come with a pretty high price tag. For example, a 500-square-meter apartment costs around USD 700,000. In return, however, tenants pay low bills thanks to the fully-insulated windows which maintain steady room temperature for hours. Additionally, each raindrop that falls onto the building is collected and reused to irrigate the condominium garden on the 25th floor. For the “340 on the Park” construction, there has been extensive use of recycled and recyclable materials, whilst air-conditioning needs are covered entirely by Thermal Chicago, a supplier providing hot and cold water to more than 100 buildings in the city of Chicago.
Bank of America Tower – New York City
Only a few months before completion, Cook+Fox Architects’ new tower had already attracted the attention of architects throughout the world. The tower, apart from being the headquarters of Bank of America, is also a real example of the shift towards the construction of “greener” buildings. In its final form, it will be a 366-metre high building with 54 floors. Construction was based on the extensive use of recycled materials, particularly slag, which is a by-product of the burning process in metallurgy furnaces mixed with cement. Light-sensitive sensors will identify solar light intensity and in turn adjust inner light accordingly, thus contributing to the reduction of power consumption. Windows are made of heat-insulating glass, which keeps the temperature inside the tower steady. The drainage system will collect approximately eight million gallons of water per year to be used by the tenants. Finally, an underground sub-station fuelled by natural gas will generate electric power, thus covering part of the building’s energy demand.
The CIS Tower Manchester, England
At a height exceeding some 120 meters, the construction of this skyscraper was completed in 1962; and for a number of years, it was the highest building in the UK. However, when its restoration was decided upon some years ago, architects came up with a bold project: the replacement of all windows by specially designed solar panels to generate electric power and the installation of 24 wind turbines at the top of the building. This was indeed what happened. And as a result, today, CIS Tower generates 180,000kW of electric power per year–a volume that corresponds to 10 percent of the total energy requirements of the building or to the power consumed by 75 households in the UK.
The Lighthouse Tower – Dubai
As yet another Lighthouse of Alexandria, the Lighthouse Tower is anticipated to leave a lasting mark on contemporary architecture. When completed, it will be a 66-story, 400-meter high edifice. Three huge, 27-meter wide wind turbines will be installed at the tower top. Each of them will generate 225kW of electric power to be added to the power generated by 4,000 photovoltaic panels on the south-facing facade. The wind turbines will spin freely in order to always face the wind and achieve maximum performance. In addition, the Lighthouse Tower will use technologies focused on reducing power consumption by 65 percent and water consumption by 40 percent, compared to other buildings of similar size.