KfW Westarkade

Frankfurt am Main
Height
1
To Tip:

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest point of the building, irrespective of material or function of the highest element (i.e., including antennae, flagpoles, signage and other functional-technical equipment).

60.1 m / 197 ft
2
Architectural:

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the architectural top of the building, including spires, but not including antennae, signage, flag poles or other functional-technical equipment. This measurement is the most widely utilized and is employed to define the Council on Tall Buildings and Urban Habitat (CTBUH) rankings of the "World's Tallest Buildings."

56 m / 184 ft
3
Occupied:

Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest occupied floor within the building.

47.7 m / 156 ft
Floors
Above Ground

The number of floors above ground should include the ground floor level and be the number of main floors above ground, including any significant mezzanine floors and major mechanical plant floors. Mechanical mezzanines should not be included if they have a significantly smaller floor area than the major floors below. Similarly, mechanical penthouses or plant rooms protruding above the general roof area should not be counted. Note: CTBUH floor counts may differ from published accounts, as it is common in some regions of the world for certain floor levels not to be included (e.g., the level 4, 14, 24, etc. in Hong Kong).

14
Below Ground

The number of floors below ground should include all major floors located below the ground floor level.

4
1 2 3 KfW Westarkade Outline
Height 56.0 m / 184 ft
Floors 14
Official Name
The current legal building name.

KfW Westarkade

Type
CTBUH collects data on two major types of tall structures: 'Buildings' and 'Telecommunications / Observation Towers.' A 'Building' is a structure where at least 50% of the height is occupied by usable floor area. A 'Telecommunications / Observation Tower' is a structure where less than 50% of the structure's height is occupied by usable floor area. Only 'Buildings' are eligible for the CTBUH 'Tallest Buildings' lists.

Building

Status
Completed
Architecturally Topped Out
Structurally Topped Out
Under Construction
Proposed
On Hold
Never Completed
Vision
Competition Entry
Canceled
Proposed Renovation
Under Renovation
Renovated
Under Demolition
Demolished

Completed, 2010

Country
The CTBUH follows the United Nations's definition of Country, and thus uses the lists and codes established by that organization.

Germany

City
The CTBUH follows the United Nations's definition of City, and thus uses the lists and codes established by that organization.

Frankfurt am Main

Address

Zeppelinallee 6

Postal Code

60325

Function
A single-function tall building is defined as one where 85% or more of its usable floor area is dedicated to a single usage. Thus a building with 90% office floor area would be said to be an "office" building, irrespective of other minor functions it may also contain.

A mixed-use tall building contains two or more functions (or uses), where each of the functions occupy a significant proportion of the tower's total space. Support areas such as car parks and mechanical plant space do not constitute mixed-use functions. Functions are denoted on CTBUH "Tallest Building" lists in descending order, e.g., "hotel/office" indicates hotel function above office function.

office

Structural Material
Steel
Both the main vertical/lateral structural elements and the floor spanning systems are constructed from steel. Note that a building of steel construction with a floor system of concrete planks or concrete slab on top of steel beams is still considered a “steel” structure as the concrete elements are not acting as the primary structure.

Reinforced Concrete
Both the main vertical/lateral structural elements and the floor spanning systems are constructed from concrete which has been cast in place and utilizes steel reinforcement bars.

Precast Concrete
Both the main vertical/lateral structural elements and the floor spanning system are constructed from steel reinforced concrete which has been precast as individual components and assembled together on-site.

Mixed-Structure
Utilizes distinct systems (e.g. steel, concrete, timber), one on top of the other. For example, a steel/concrete indicates a steel structural system located on top of a concrete structural system, with the opposite true of concrete/steel.

Composite
A combination of materials (e.g. steel, concrete, timber) are used together in the main structural elements. Examples include buildings which utilize: steel columns with a floor system of reinforced concrete beams; a steel frame system with a concrete core; concrete-encased steel columns; concrete-filled steel tubes; etc. Where known, the CTBUH database breaks out the materials used in a composite building’s core, columns, and floor spanning separately.

composite

Height
Architectural
Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the architectural top of the building, including spires, but not including antennae, signage, flag poles or other functional-technical equipment. This measurement is the most widely utilized and is employed to define the Council on Tall Buildings and Urban Habitat (CTBUH) rankings of the "World's Tallest Buildings."

56.0 m / 184 ft

To Tip
Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest point of the building, irrespective of material or function of the highest element (i.e., including antennae, flagpoles, signage and other functional-technical equipment).
60.1 m / 197 ft
Occupied
Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest occupied floor within the building.
47.7 m / 156 ft
Floors Above Ground
The number of floors above ground should include the ground floor level and be the number of main floors above ground, including any significant mezzanine floors and major mechanical plant floors. Mechanical mezzanines should not be included if they have a significantly smaller floor area than the major floors below. Similarly, mechanical penthouses or plant rooms protruding above the general roof area should not be counted. Note: CTBUH floor counts may differ from published accounts, as it is common in some regions of the world for certain floor levels not to be included (e.g., the level 4, 14, 24, etc. in Hong Kong).

14

Floors Below Ground
The number of floors below ground should include all major floors located below the ground floor level.

4

# of Elevators
Number of Elevators refers to the total number of elevator cars (not shafts) contained within a particular building (including public, private and freight elevators).

8

Construction Schedule
2004

Proposed

2007

Construction Start

2010

Completed

Architect
Design

Usually involved in the front end design, with a "typical" condition being that of a leadership role through either Schematic Design or Design Development, and then a monitoring role through the CD and CA phases.

Structural Engineer
Design

The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.

Other Consultant

Other Consultant refers to other organizations which provided significant consultation services for a building project (e.g. wind consultants, environmental consultants, fire and life safety consultants, etc).

Material Supplier

Material Supplier refers to organizations which supplied significant systems/materials for a building project (e.g. elevator suppliers, facade suppliers, etc).

Elevator
Owner
KfW Bankengruppe
Architect
Design

Usually involved in the front end design, with a "typical" condition being that of a leadership role through either Schematic Design or Design Development, and then a monitoring role through the CD and CA phases.

Architect of Record

Usually takes on the balance of the architectural effort not executed by the "Design Architect," typically responsible for the construction documents, conforming to local codes, etc. May often be referred to as "Executive," "Associate," or "Local" Architect, however, for consistency CTBUH uses the term "Architect of Record" exclusively.

Architekten Theiss Planungsgesellschaft mbH
Structural Engineer
Design

The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.

MEP Engineer
Design

The Design Engineer is usually involved in the front end design, typically taking the leadership role in the Schematic Design and Design Development, and then a monitoring role through the CD and CA phases.

Reuter Rührgartner GmbH; Zibell, Willner & Partner
Contractor
Main Contractor

The main contractor is the supervisory contractor of all construction work on a project, management of sub-contractors and vendors, etc. May be referred to as "Construction Manager," however, for consistency CTBUH uses the term "Main Contractor" exclusively.

Züblin
Other Consultant

Other Consultant refers to other organizations which provided significant consultation services for a building project (e.g. wind consultants, environmental consultants, fire and life safety consultants, etc).

Material Supplier

Material Supplier refers to organizations which supplied significant systems/materials for a building project (e.g. elevator suppliers, facade suppliers, etc).

Elevator

CTBUH Awards & Distinctions

Best Tall Building Worldwide 2011 Winner

2011 CTBUH Awards

Best Tall Building Europe 2011 Winner

2011 CTBUH Awards

CTBUH Initiatives

Werner Sobek Presents on Engineering High-Rises for Sustainable Cities

11 June 2013 - Conference Video

KfW Westarkade Chosen as Featured Building

1 December 2011 - Featured Building

Videos

11 June 2013 | Frankfurt am Main

Beyond Green – Engineering High-Rises for Sustainable Cities

High-rise buildings make an important contribution in the design of sustainable cities – provided they are planned accordingly and with a holistic perspective. In this...

About KfW Westarkade

One of the first office towers in the world predicted to run on less than 90 KWh/m² of primary energy per year, KfW Westarkade uses approximately half the average energy of European office buildings, and one-third of American. The building forms a 14-story extension to the KfW’s headquarters in Frankfurt, completing an existing ensemble of buildings from the last four decades. Situated in the city’s West End, it lies adjacent to the Palmengarten park and includes space for conference facilities and 700 new workplaces.

The streamlined shape of the tower integrates itself into the cluster of existing buildings. It acts as a colorful interface between two distinct urban spaces: while it appears as a slim slab towards the city, it presents a discreet backdrop to the park and provides open sightlines for the existing ensemble. Furthermore it exploits the prevailing wind direction for controlled natural ventilation of the offices by means of its unique double layered wind-pressurized façade.

The new building extends the grounds of the KfW Banking Group to the west with a four-story podium that clearly delineates the edge of the Zeppelinallee road. The tower above it is formed in such a way that it does not obstruct the view from the existing office floors of the main building. Together with the main buildings and the adjacent existing structure, the building’s south side creates a communal courtyard. The landscaped areas of the southern end of the Palmengarten are drawn through the site leading to this courtyard, resulting in a coherent and interesting open space.

The construction and use of the Westarkade is governed by numerous built and behavioral features to maximize sustainability, led by three factors: natural ventilation, activated slabs, and geothermal energy.

The Westarkade had as its primary aim to make a significant advance in the field of natural ventilation of tall buildings, as a significant component of their overall sustainability. The dynamically-controlled pressure-ring façade serves to neutralize external wind conditions which are otherwise too turbulent for operable windows, especially on higher floors. The façade’s outer layer contains sensor-controlled flap openings that maintain a constant and even air pressure within the ring. The inner layer has operable windows that allow the offices within to be ventilated. The air flow within the pressure ring is regulated to never exceed 6 m/s. The flaps are designed to adjust to five wind directions as well as outside temperature, solar radiation and pressure differences on the windward and leeward sides of the building.

Exhaust air flows through noise-attenuating overflow elements in the office partitions and along corridors until it reaches the cores, where the air, through stratification, is naturally driven upward to the roof through shafts.

As a result, the offices can be ventilated naturally for eight months of the year without creating drafts or undesired heat loss. Mechanical ventilation is required for less than 50% of all working hours. The double façade also functions as a passive thermal solar collector, as the flow of fresh air is pre-tempered by solar radiation within the double façade. In this way heat loss is minimized and heat energy is conserved. The outer skin of the double façade can be opened completely in order to avoid overheating of the building in summer.

The building employs thermally activated slabs, whereby a system of pipes built into the solid floors conveys water that serves as both a heating and cooling medium. This creates exceedingly energy-efficient, comfortable and constant room temperatures. Due to the high thermal storage capacity of the solid concrete floors, the rooms can be sustainably heated and cooled without the extremes in water temperature that are required with traditional radiators. For this sort of tempering, energy can be used that already exists in the building: the waste heat from the data processing center can cover half of this heating demand.

Geothermal energy is provided through an air source heat pump which complements the recovery-based heating system within the KfW complex. Largely contaminant-free air is drawn from the adjacent Palmengarten park, then tempered by traveling though a system of underground conduits before being distributed inside.

CTBUH Awards & Distinctions

Best Tall Building Worldwide 2011 Winner

2011 CTBUH Awards

Best Tall Building Europe 2011 Winner

2011 CTBUH Awards

11 June 2013 | Frankfurt am Main

Beyond Green – Engineering High-Rises for Sustainable Cities

High-rise buildings make an important contribution in the design of sustainable cities – provided they are planned accordingly and with a holistic perspective. In this...

03 November 2011 | Frankfurt am Main

Best Tall Building Europe: KfW Westarkade: The Next Generation of Energy Efficiency

One of the most energy-efficient office buildings in the world, KfW Westarkade is projected to use about half the primary energy of an average European...

03 November 2011 | Frankfurt am Main

CTBUH 10th Annual Awards Dinner

The 10th Annual Awards Ceremony & Dinner was held in Mies van der Rohe’s iconic Crown Hall, on the Illinois Institute of Technology campus, Chicago....

03 November 2011 | Frankfurt am Main

Interview: Engineering the KfW Westarkade

Werner Sobek is founder of Werner Sobek Group, one of the world’s leading engineering consultancies. He speaks on sustainability and lightweight structures as well as...

03 November 2011 | Frankfurt am Main

Interview: KfW Westarkade

The winner of the 2011 Best Tall Building Europe, KfW Westarkade in Frankfurt, is also the winner of the Overall Best Tall Building Worldwide. Axel,...

11 June 2013

High-rise buildings make an important contribution in the design of sustainable cities – provided they are planned accordingly and with a holistic perspective. In this context, the design of structural systems and façades make a vital contribution. In this presentation, from one of the world’s most distinguished engineers, we see selected research and completed projects demonstrating how we can not only use significantly less materials and energy, but also achieve a considerable rise in user comfort and functionality through innovative design concepts. The resulting buildings are truly sustainable – especially when taking into consideration their whole life-cycle.

1 December 2011

KfW Westarkade Chosen as Featured Building

Already being touted as one of the most energy-efficient office buildings in the world, KfW Westarkade stands out as a shining example of a truly environmentally-responsible project.

3 November 2011

One of the most energy-efficient office buildings in the world, KfW Westarkade is projected to use about half the primary energy of an average European office building, and one-third of a North American one. Its appearance is a direct expression of an holistic approach to sustainability. Its sophisticated envelope mediates natural thermal conditions and acts as a colorful interface between the distinct urban spaces of its context.