Sustainable by design 2050

An initiative of the UIA

Velux model home 2020

Activehouse

Sapienza_Universit___di_Roma

Architekturclips

KfW Westarkade

KfW Westarkade

Photographer: Jan Bitter

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isometric_context

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high_rise_floor

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third_floor

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first_floor

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ground_floor

KfW Westarkade
Architect
Sauerbruch Hutton
Engineers/Specialists
Energy Concept - Transsolar Energietechnik GmbH, Structural Engineers - Werner Sobek Group, MEP Engineers - Reuter Rührgartner GmnH, HVAC - ZWP Ingenieur-AG
Location
Western Europe - Germany - Frankfurt
Climate Zone
temperate
Design status
build
Date of completion
2009
Type
Office
Site area (m²)
5027
GFA (m²)
39000
NFA (m²)
11000
NFA/GFA
0.282
Density
7.758
Gross Volume (GV) (m³)
76582
Building Costs
95000000 EUR
Building Costs / m² GFA
2435.897
Building Costs / m² NFA
8636.364
Building Costs / m³ GV
1240.5
Primary Energy (kWh/m²a)
82
Heating Energy (kWh/m²a)
44
Cooling Energy (kWh/m²a)
22
Cooling / Heating-System

In the summer months concrete slabs are  cooled through a system of pipes embedded within them containing water cooled to approximately 18°C. The concrete mass of the ceilings stores this coolth, which is then released to the surroundings during the day. Should the free cooling capacity be insufficient, additional refrigeration is available from KfW's cooling network. Heating of the office spaces in winter is likewise achieved through the same thermo-activated slabs. Here, as a first source, waste heat from the data processing centre is used, and, if needed, KfW's integrated heating network is used as a supplement.

Use of renewable ressources - low tech
natural cross ventilation, wind towers, use of high thermal mass, others
Use of renewable ressources - high tech
solar heating, heating pump, geothermal energy use, energy recuperation, energy storage, thermal building mass activation, other
Key Sustainability aspects
solar building integration, public spaces, accessability for disabled, renewable building materials, ecological building materials, innovative bulding materials, integrated planning process, participation of users in planning process, use of innovative design tools
Sustainability rated
Other
Social and ethical responsibility

The KfW Westarkade building successfully fulfils the company’s high expectations of comfort and working atmosphere for its employees while simultaneously reaching the goal of a maximum annual primary demand of 100 kWh/sq m. Sustainable design is an ethic that was embedded in the whole project, relating it directly to individuals. Every detail was carefully designed bearing the end-user in mind in order to create an ecologically compatible working environment.

Ressource efficiency and environmental impact

The energy balance of the Westarkade building is achieved through the combination of various passive and active measures. The pressure-ring façade offers natural ventilation that is independent of weather, high heat insulation and effective external sun protection. The thermal activation of the ceilings allows for consistent conditioning of the office spaces with minimal energy expenditure and provides maximum comfort for employees. The optimisation of glazed areas that negotiates between daylight utilisation and the build-up of summertime heat reduces the electricity required for lighting. On-hand energy sources are exploited through heat recovery and the recycling of waste heat produced by the data processing centre.

Economic lifecycle perfomance

The building is currently being monitored by institutions such as KIT, therefore no results are available yet.

Contextual performance and impact

The volume of the 56 metre high building has been integrated within the cluster of existing towers in such a way that the skyline of these buildings remains visible from Zeppelinallee while, correspondingly, views out from these offices are maintained. At the same time the new high-rise acts as an interface between two distinct urban spaces: while appearing as a slim slab towards the street, it presents a discreet backdrop to the landscape of the Palmengarten. The flowing form of the building’s socle defines the edge of the street, taking up the eaves height of the neighbouring North Arcade building. The façade is set back at ground level to create a protective arcade to the street, while the landscape of the Palmengarten is drawn seamlessly into the rear of the site to create a generous open space.