Denk- und Kommunikationsansätze zur Bewertung des Nachhaltigen Bauens und Wohnens anhang der Ökologischen Wohnsiedlung Flintenbreire in Lübeck
It is the aim of the present study to detect the reasons for these grievances, taking as an example the new Ecological Housing Estate Flintenbreite, and to demonstrate alternative solutions. For this purpose, different concepts of assessment are employed which meet the requirements of a full life cycle analysis. From the ecological perspective, these are the software tool GaBi of the University of Stuttgart, the MIPS concept of the Wuppertal Institute for Climate, Environment, Energy as well as the software tool GEMIS from the Eco Institute. In order to assess the quantity and quality of the area consumption, a special calculation method was developed on the basis of “Hemerobiestufen”, which illustrate the degree of naturalness of a surface area. The BKI Kostenplaner of the Baukosteninformationszentrum is used to analyze the economic factors. In order to assess social aspects, a special assessment method on the basis of national and international discussions is developed and applied.
Apart from taking into account generally accepted ecological indicators, this study also attempts to develop economic indicators as well as indicators for measuring social sustainability of housing development concepts. By means of a working example the practicability of these indicators is examined.
For assessing the degree of sustainability reached at the Ecological Housing Estate Flintenbreite 15 indicators are used. These are:
• The Total Material Requirement (TMR)
• The Accumulated Expenditure of Energy (KEA)
• The Global Warming Potential related to 100 years (GWP 100)
• Area consumption
• Water consumption
• Planning and implementation costs
• Costs of construction and production
• Costs of utilization including maintenance costs
• Costs of pulling down, disposal and restoration
• Average renting costs
• Age composition of the residents
• Income structure of the residents
• Unemployment rate of the residents
• Quota of women employed
• Possibilities of participation of the residents
For assessing and visualizing the several indicators, the COMPASS method, developed at the Wuppertal Institute, is applied.
Since the process of construction at the Ecological Housing Estate Flintenbreite has been delayed as a result of the insolvencies of two of the developing companies, up to date only 26 of the planned 119 housing units have been completed. Therefore, in order to obtain valuable results the scientific approach had to be reduced in the course of this study. As the central elements of the approach the building above ground and the sewage concept, which has been used on a larger scale for the first time and which is based on a vacuum technique, are focused on. Apart from savings in water (only 1 liter per flush), this trend-setting, integrated sewage concept takes into account the utilization of nutrients and the energy content of excrements and biological waste. For that purpose, the flows grey water (residues without excrements), black water (toilet residues), rainwater and biological waste are dealt with separately within the whole concept. Through the fermentation of biological waste and excrements, biogas is won which is then used for power production in the housing estate’s own cogeneration plant. Three filters (constructed wetlands in the form of sand filters planted with reeds) are used for clearing the grey water. Using hollows on the 4.9 hectare wide housing development area, rainwater can seep away directly. The liquid manure remaining after anaerobic treatment is collected in a reservoir and used for agricultural means. Thus, nutrient cycles can be completed.
Despite partly positive results it must be stated that these building measures, with regard to the building above ground, do not make a valuable contribution as far as more sustainable building is concerned. The sewage concept appears to be more apt to meet this requirement, although optimizing steps have yet to follow.
Stakeholders from many different fields can take such steps in their respective discipline but also with regard to the interdisciplinary perspective. The chance to act beyond the boundaries of one’s own discipline, the ability to communicate as a key to joint action as well as the ability to see and open up new paths require new approaches and possibilities of acting. Thus, it is the duty of private persons, functionaries and elected candidates alike to help ensure corresponding education and qualification.
Apart from that, on the international level, it is essential to initiate a changed, honest and consistent orientation of the rules of the WTO, the ILO and the UNEP without which a sustainable development will continue to be a utopia.
And perhaps we may even have to go one step further and overcome an economy of interest and compound interest that is destroying resources, in order to be able to live the dream of a sustainable economic system.