هذا البنك التجاري المكون من ثلاثة وخمسين طابقاً هو أول برج مكاتب بيئي في العالم، وهو أطول مبنى في أوروبا. وقد كان الغرض من هذا المشروع هو استكشاف طبيعة المبنى المكتبي المرتفع، وتطوير أفكار جديدة لعلاقته بالبيئة وأنماط العمل به. وفي صلب هذا المفهوم الاعتماد على الأنظمة الطبيعية للإضاءة والتهوية. فجميع المكاتب يغمرها ضوء النهار، وتحتوي على نوافذ قابلة للفتح، مما يتيح للموظفين التحكم في بيئة العمل المحيطة بهم. فكانت النتيجة مبنى بمستويات استهلاك طاقة تعادل نصف المستويات الموجودة في الأبراج المكتبية التقليدية. 

يأخذ مخطط المبنى الأفقي شكل المثلث، حيث يضم ثلاث "بتلات" ـــــ طوابق المكاتب ـــ و"جذعاً" يشكله الفناء المركزي ذو الارتفاع الكامل. وتلتف الحدائق الشتوية حول الفناء باتجاه الأعلى لكي يصبح المركز الاجتماعي والبصري  لمجموعات المكاتب المكونة من أربعة طوابق. كما وتضفي "حدائق السماء" هذه على المبنى من الخارج شعوراً بالشفافية والخفة. أما من الناحية الاجتماعية، فهي تشكل نقاطاً محورية لمجموعات المكاتب التي تشبه القرية الصغيرة، مما يوفر أماكن للالتقاء بزملاء العمل أو الاسترخاء أثناء فترات الاستراحة. ومن الناحية البيئية، تساعد الحدائق على انسياب ضوء النهار والهواء النقي إلى داخل الفناء المركزي، الذي يعمل كـ"مدخنة" للتهوية الطبيعية للمكاتب المطلَّة على الداخل. وتبعاً لاتجاه كل حديقة، تم اختيار النباتات من أحد الأقاليم الثلاثة التالية: أمريكا الشمالية، أو آسيا، أو منطقة حوض البحر الأبيض المتوسط.

يتمتع البرج بوجوده المميز في أفق فرانكفورت، ولكنه يستقر أيضاً في النسيج الحضري المنخفض الحجم عبر عمليات تجديد الإنشاءات المحيطة والمحاولات الحساسة لإعادة بنائها بشكل ملائم لتعزيز الحجم الأصلي لتجمع البنايات المحيطة. وتوفر هذه المباني محلات تجارية، وساحات لاصطفاف السيارات، وشقق سكنية، وقاعة بنكية؛ كما تساعد على إقامة روابط بين البنك التجاري والمجتمع الأعم. يوجد في قلب هذا المخطط رواق عام يحتوي على مطاعم ومقاهٍ، بالإضافة إلى فضاءات مخصصة للأحداث الثقافية والاجتماعية، كما أنه أصبح ممراً مفضلاً للعامة. ومن المثير للدهشة أنه في اليوم الذي تم فيه افتتاح مبنى البنك التجاري، اتخذته صحيفة "فاينانشال تايمز" كرمز لفرانكفورت، تماماً كما سبق لها وأبرزت مجلسي البرلمان، وبرج إيفل باعتبارهما رمزين للندن وباريس.

الرسوم التخطيطية + الرسومات

التطوير

التشييد

الاستدامة

Site + Climate

The building design responds to prevailing winds and solar orientation, to ensure optimum ventilation and daylight penetration.

Form + Massing

The triangular shape and central atrium assisted in the creation of a zone of negative pressure, that drives natural ventilation through the building.

Passive Design

The building was designed to be naturally ventilated for 60% of the year, with the sky gardens allowing natural ventilation during shoulder seasons. This approach was expected to reduce energy consumption by up to 50% compared to an equivalent air conditioned office.

Environmental Systems

Cooling is provided by chilled ceilings, while heating is from perimeter heating. Windows are connected to the BMS to ensure that the mechanical ventilation only works when the windows are closed. Artificial lighting is connected to motion sensors and timers.

Renewable Energy

From 1st January 2008, the Commerzbank Tower has been supplied exclusively with green energy that is derived from renewable energy sources.

Mobility + Connectivity

The central infill site location of the project, is also key to its connectivity and access as it is close to public transport links.

Materials + Waste

The development reused and restored the existing perimeter buildings which reduced materials consumption. Even before the existence of the Forestry Stewardship Council, all timber used in the building was taken from managed sources. Operational waste segregation facilities are provided and catering waste is composted.

Water

To reduce potable water consumption, the condensate from the chillers was recycled, and used for WC flushing

Land + Ecology

Large sky gardens with a diverse ecological profile were used to provide informal break out spaces with views of the city. This incorporation of landscaping, and the other sustainable design responses, led to Commerzbank being dubbed as the world’s first ‘ecological office tower’.

Culture + Heritage

The tower, built in the centre of Frankfurt, was designed with respect to existing historical structures and the buildings surround. The project reused and restored the existing perimeter buildings of the site, which helped to maintain the streetscape.

Wellbeing

Designed with the end user in mind, office areas are naturally ventilated and flooded with daylight. Users can regulate their own environments and sky gardens act as a breakout space.

Prosperity

The tower has been embraced by the city, and Commerzbank is now regularly shown as an iconic structure of Frankfurt, and the German stock exchange.

Planning for Change

As the first ‘ecological office tower’, the sustainable approach for the project was ahead of its time. The design planned for a future of increasing resource scarcity and cost, by minimising energy and water consumption, whilst providing solutions for enhanced comfort.

Performance in Use

Post occupancy studies have shown that the tower actually consumes 20% less energy than predicted, and there has been a year on year reduction in energy consumption since 2000. This is largely because the building users have extended the period of natural ventilation up to 85% of the year, as opposed to the 60% designed for.

الاقتباسات

"We now have five years' experience of running the building

and I am very happy to report that it is actually far more efficient in energy terms than was anticipated at the design stage. For example, whereas it was estimated that the building would be naturally ventilated for 60 per cent of the year, we are in fact able to use natural ventilation for more than 80 per cent of the time. This means that our present electricity usage is approximately 20 per cent less than predicted. As you might imagine, we are very happy."Peter Muschelknautz, the Commerzbank Facilities Manager 2002 "We now have five years’ experience of running the building, and I am very happy to report that it is actually far more efficient in energy terms than was anticipated at the design stage. For example, whereas it was estimated for 60 per cent of the year, we are in fact able to use natural ventilation for more than 80 per cent of the time. This means that our present electricity usage is approximately 20 per cent less than predicted. As you might imagine, we are very happy."Peter Muschelknautz, The Commerzbank Facilities Manager 2002 "We are given lots of praise when our office workers leave at night and tell us that they don't feel tired - this means that their productivity increases. This is more important to me than great architecture or sky gardens."Dr Horst Gruneis, director of Commerzbank's Central Building department quoted in Architectural Record, January 1998 "At last we can open the windows whenever we like, we can feel the air and the noises of the street - we feel freer."Unnamed Commerzbank employee quoted in Frame 1, December 1997 "As the interiors of Foster’s Commerzbank come together, the most striking effect is one of glistening transparency." Barrie Evans, The Architects’ Journal, 27 March 1997 "This architecture speaks of a better world – on the one hand, highly technical; on the other, ecologically defensible."Manuel Cuadra, Domus, November, 1997 "At last we can open the windows whenever we like we can feel the air and the noises of the street – we feel freer." Unnamed Commerzbank employee, quoted in Frame, 1 December 1997 "You sense that a kind of community has been created, one that could become familiar and intimate, so unlike the usual downtown tower."Mary Pepchinski, Architectural Record, January 1998 "With the Commerzbank we combined an ambitious structural and aesthetic vision with a quest for natural ecological solutions and the well-being of the individual. For me, it is in this synthesis of these themes that the real achievement lies."Norman Foster

الحقائق والأرقام

  • التعيين: 1991
  • الإكمال: 1997
  • المنطقة: 120 736m²
  • الارتفاع: 298m
  • القدرة: 2400
  • العميل: Commerzbank AG
  • المهندس الإنشائي: Ove Arup & Partners / Krebs & Kiefer
  • المساح: Davis Langdon & Everest
  • مهندس M+E: Roger Preston & Partners/ RP&K Sozietat GmbH/ Petterson & Ahrens
  • مهندس المناظر الطبيعية: Sommerland & Partners
  • مهندس إضاءة: Lichtdesign

الجوائزs

  • Green Building Award of the City of Frankfurt
  • RIBA Architecture Award
  • Bund Deutscher Architekten - Martin-Elsaesser-Plakette Award
  • British Construction Industry Awards, International Award to

ملامح:

Winter gardens linked to a central atrium spiral up the tower to become the visual and social focus for four-storey clusters of offices.