On November 3, the Council on Tall Buildings and Urban Habitat announced the winner of its annual "Best Tall Building Worldwide 2011". KfW Westarkade (Frankfurt, Germany) by Sauerbruch Hutton architects named as the 2011 Overall "Best Tall Building Worldwide" during 10th Annual Awards Ceremony, reported CTBUH.rog. The architects at Sauerbruch Hutton, Germany have built the world's most energy efficient glass tower using "pressure ring facade" in 2010. The architecture incorporated the facade design developed in 1990s which managed excess sunlight in glass towers while building the 15 story glass tower in Frankfurt, Germany. The design includes a pressure ring facade, the first of its kind, reducing the effects of changes in the pressure around the building and enhancing natural ventilation. Complex and highly sophisticated computer controlled flaps in the outer facade open and close and equalize the pressure throughout. The inner windows can be opened and strong winds entering the building are prevented. The building's control system constantly gets a feedback from a rooftop weather station and from 40 sensors installed all around the building which measure pressure, temperature and sunlight. The system also has geothermal heat exchangers, heat capturing modules from basement data center and heat recovered from vented air. All this reduces the tower's primary energy demand to less than 100 Kwh of energy per square meter per year. It is approximately half of the current European average, and one third of the American. The need for the mechanical ventilation will be almost eliminated in fall and spring as air from open windows will be available. The unwanted summer heat is rejected by the Venetian blind installed horizontally. On the other side, pane of glass over the blinds and provided with ventilation at both top and bottom protects blinds from strong winds. This posed a major problem that when windows were opened, pressure difference created around the tower sent drafts across the floor which flew everything.

According to ctbuh.org, the Council on Tall Buildings and Urban Habitat announced the winners of its annual "Best Tall Building" awards for 2011. This year's winners will be recognized, and the awards conferred, at the CTBUH 10th Annual Awards Ceremony on October 27. All the winning projects and finalists will be celebrated at this gala event. Additionally, from the four regional best tall building winners, one overall winner will be selected and bestowed with the "Best Tall Building Worldwide" award, to be announced on the night. This year are awarded to: "New York by Gehry" at Eight Spruce Street, New York (Americas); Guangzhou International Finance Center, Guangzhou (Asia & Australasia); KfW Westarkade, Frankfurt (Europe); and The Index, Dubai (Middle East & Africa). These buildings were selected for their design and technical innovations, sustainable attributes, and the enhancement of both cities and the lives of their inhabitants. Developer of winner in region America "New York by Gehry" is Forest City Ratner Companies. 76 - storey and 265 meters high building's architectural design is belonged to Genry Architects New York. With 102 thousand square meters total area, this building is completed in April 2011. Total budget of this residential tower was US$ 174 million. Developer of Guangzhou International Finance Center is Yue Xiu Group, and architectural design is belonged to Wilkinsone Eyre Architects. With 250 thousand square meters total area 103-storey and 440 meters high world's ninth tall building was completed on 2010. Main contractors of project were China State Construction Engineering Corporation LTD and Guangzhou Municipal Construction Group CO LTD. Total budget of Wilkinson Eyre's first high-rise tower was nearly US$ 410 million. KfW Westarkade is Europe region winner. Developer of 14 - storey, 56 meters tall building is KFW Bankengruppe. Construction of tower completed in May 2010. Architectural design is belonged to Sauerbruch Hutton. Middle East & Africa region winner 80-storey, 326 meters high Index Tower was designed by Foster+Partners architectural company, and main contractor was Brookfield Multiplex. The developer of 170 thousand square meters residential/office tower is Union Properties. Construction works were completed in March 2011. You can read about "Best Tall Building 2010" here.