Since pile foundations were necessary, water-bearing pipes were installed in roughly 500 of the piles. In winter, these convey geothermal heat into the building, while in summer, they serve cooling purposes. An ingeneous ventilation concept, energy-efficient light fittings and a highly insulated building skin also help to ensure that the development uses only about a third of the energy of a comparable building in a conventional form of construction.
The “etrium” in Cologne – also awarded the DGNB Seal in Gold – can be operated to conserve resources in a similar way. The architectural practice Benthem Crouwel designed an office building that requires 70 per cent less primary energy than a conventional structure of this kind. Optimum daylighting through the central atrium, the use of rainwater for flushing toilets, and a large-area photovoltaic installation on the roof (with an annual electrical yield of 30,000 kWh) are further attributes.
At the planning and process phases, a DGNB-trained auditor comes on the scene. In the Paul Wunderlich House project, Günter Löhnert of the Solidar Planungswerkstatt in Berlin assumed this role, with responsibility to integrate all the parties involved in the conduct of the scheme. The DGNB wants to present an updated version of the certification system this year and plans to include not just administration and office buildings in the evaluative process, but existing structures and housing as well.
The DGNB seal of quality is also awarded to buildings that have not yet been built. A preliminary certificate of this kind has been issued to the project Europe Plaza, an office building in the urban development area Stuttgart 21, which is at present being planned by the Cologne office of JSWD Architects. The proposed atrium of this building will allow natural ventilation and at the same time provide a high-quality leisure space. In addition, there will be great flexibility. Since the building will have four access cores, each standard floor can be divided into as many as eight leasable segments.According to project architect Thorsten Burgmer, the DGNB criteria are a good counterpart to the planning standards already in use at JSWD. The implementation of the DGNB guidelines is nevertheless a complex matter, as can seen in the facade. According to Burgmer: “Choosing stone from Portugal because it is cheaper can result in additional points under the heading of economy, but it can also earn minus points ecologically because of the transport.
For advocates of the DGNB seal of quality it is by no means inconsistent that a preliminary certificate can be issued, even though the implementation of a scheme is not fixed in detail. Günter Löhnert describes it as follows: “The seal of quality serves as a means of optimizing the planning and development of the project.” And for the architect Thorsten Burgmer, the challenge lies in complying with as many requirements as possible in terms of the sustainability of the building – and in the end still “coming up with something beautiful”.
