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Office building, Holzbrücke
The student design for the “Tilting Shell” office building in Hamburg demonstrates how the energy-based refurbishment of an administration building can combine energy efficiency with aesthetically convincing means. In addition to solar and sound protection elements, facade-integrated photovoltaic systems considerably enhance the appearance. A special feature of the energy concept is the in-house water treatment system that enables the utilisation of rainwater.
How the judges assessed it:
“As part of the energy-based renovation of an existing office building in Hamburg, it was investigated how increasing the efficiency and the use of environmental energies can be harmonised in a creatively convincing manner. A highly insulated envelope has been created in the form of a polyvalent double facade. The facade-integrated photovoltaic system and the solar and sound protection elements, which have been matched with the orientation of the building, respond to the local conditions and the user comfort requirements. The work impresses through its high degree of thoroughness, the energy-based analysis and the structural implementation, whereby unfortunately too little consideration was given to the daylight utilisation. In addition to her sophisticated approach taken to the existing building in regards to the functional and energy-based aspects, the designer grasped the opportunities arising from the targeted use of environmental energy to develop the design quality of the building.”
Building concept
The usage concept has been redefined for both blocks. The west block is earmarked for a fixed tenant for the next 10 years, while each floor in the east block can be rented on an individual basis. The office spaces in the east block are arranged around a central core and provide workspaces on the north and south elevations. The core zone comprises the reception area, toilets, kitchen, conference room and the air conditioning systems. In the west block, the circulation block, toilets, kitchen and server room create a compact unit along the east elevation. The office spaces are arranged in a C-shape along the south, west and north facades. The ground floor provides space for different usages.
The vertical circulation block is situated centrally between the west and east blocks. Wheelchair access will be ensured by means of a new ramp located at the front. The expansion of the foyer area by means of the space surrounding the ramp and the gallery on the first and second floors is representative in character and provides an opportunity to integrate a corporate design. The entire circulation block is also intended to provide a space for visual communication. Projecting and recessed floor plates and bridges create visual relationships between the different levels.
Energy concept
The ventilation concept for the building resulted from the optimised office floor plans and the stipulation to provide heat recovery that is as efficient as possible. In the east block, a central function zone will house the toilet facilities, kitchen and temporary conference room on each floor. The central air conditioning system will be installed floor-wise.
On evaluating the site, it became clear that it made sense to use the existing district heating connection, since the primary energy factor of 0.568 is extraordinary low and enables sustainable energy provision for the building, particularly at the urban level.
Via a heat exchanger, the surplus waste heat from the power plant is used to heat the domestic hot water. This project adopts a particularly responsible approach to treating water: rainwater is captured on the roof of the west block and is used for flushing the toilets.