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Children’s day care centre, Bochum
The children’s day care centre in Bochum is intended to be a zero-emissions building. The overall aim is even more ambitious: zero emissions when balanced across the year, non-fossil fuel energy supplies and an improvement on the requirements of EnEV 2009. To achieve these goals, concepts for optimising the daylight, supplying geothermal-based heating and providing passive cooling were developed.
How the judges assessed it:
“In urban development terms, the new kindergarten has evolved very naturally out of the existing context, special topography and the usage concept. An existing slope is very ingeniously utilised for structuring the internal floor plan and for shaping the physical appearance.
The building’s structural concept, the urban constellation and the topography are logically and profitably applied as part of the building’s energy concept. This is particularly shown in the zoning and orientation of the main spaces towards the north, the daylight illumination of the central play area via the generously sized north-facing skylight and the south-facing roof that is furnished with a photovoltaic system.”
Building concept
The development of a lifecycle analysis is used to document the performance of the alternative structural design as a sustainable lightweight timber structure relative to conventional building structures. It intends to show by way of comparison the primary energy used in the building structure, the toxic loads and the key economic data for the project.
By coupling the building to an existing energy supply network, the seasonally deviating energy demand will be balanced against the likewise seasonally deviating energy generation. The energy generated by the building using renewable energy supplies will be compared with the energy consumption and the associated CO2 emissions throughout the year, whereby the intention is to achieve a neutral energy and emissions balance across the year. The building for the children’s day care centre in Brünselstrasse shall therefore be produced as a zero-emissions building.
Energy concept
This kindergarten is designed to achieve a high energy and ecological standard, whereby the following measures will be implemented:
high quality thermal protection with insulation thicknesses of between 20 and 30 cm in the facade and roof and with 12 cm thermal insulation to the ground, triple-glazed insulating glass units and a building structure with a low primary energy content as a result of using prefabricated timber construction elements.
An important element is the central ventilation system with more than 80% heat recovery, which will use adiabatic cooling with fresh water where required. Outside of the heating period it is also possible to provide ventilation using the windows in all externally facing areas. This is intended to save energy required for driving the ventilation system. The building will be lit with T5 fluorescent lamps, partly using daylight control. Presence detectors will be used in internal spaces.
The remaining heating requirement will be met using (geothermal) borehole heat exchangers, whereby 2 to 3 borehole heat exchangers with lengths of around 100 metres will be used as the heat source. The heat will be removed using a brine heat pump. In order to ensure the high efficiency of the heat pump, underfloor heating will be used with supply temperatures of around 30 °C.
By combining all these measures, it is intended to undercut the primary energy requirements stipulated by EnEV 2009 by more than 60%. The remaining energy requirements will be met using 100% renewable energy using a photovoltaic system.