Benchmarks for sustainable construction A contribution to develop a standard

Abstract Sustainability has been enshrined as a goal of society to ensure that the satisfaction of present needs does not compromise the ability of future generations to meet their own needs. It is thus a social objective, achievable only where all areas of society co-operate in fulfilling the associated demands. Ecological sustainability is, in turn, a basic prerequisite for sustainable economic and social development. The first step in formulating an effective response to this challenge, focused solely on the environmental issues, entails a quantification of the contribution required from the various areas of human activity for the achievement of sustainable development. Without binding sub-targets for the different sectors, it will be all but impossible to move systematically towards a sustainable society. These benchmarks for sustainable construction therefore set out to define the requirements to be met by buildings and structures in contributing to the achievement of a sustainable society. The permissible impact of buildings, in terms of energy demand and pollutant loads, during construction, maintenance and operation is determined. The analysis focuses on identifying the permissible levels of loads based on the specific energy consumption per m 2 and year for heating, hot water, electricity and construction. A conscious attempt is made to combine existing methods with the general political consensus by taking account of: - the ecological scarcity method [G. Brand, A. Scheidegger, O. Schwank, A. Braunschweig, Bewertung in Okobilanzen mit der Methode der okologischen Knappheit (Life cycle analysis using ecological scarcity method), Environmental Publication no. 297, Swiss Agency for the Environment, Forests and Landscape (SAEFL), 1997] used to define critical pollutant loads; - the limitation of greenhouse gas emissions specified by the intergovernmental panel on climate change (IPCC) [Intergovernmental Panel on Climate Change, Climate Change 2001, IPCC Third Assessment Report, www.grida.no/climate/ipcc_tar/ ]; - the demands of the 2000 W society [Leichter leben – Ein Verstandnis fur unsere Ressourcen als Schlussel zu einer nachhaltigen Entwicklung – die 2000-Watt-Gesellschaft (Easier living – understanding our resources as the key to sustainable development – the 2000 Watt society), novatlanis, sia, energieschweiz, January 2005] for the conservation of energy resources. The study shows that buildings designed to the Passive House standard just about comply with the requirements for sustainable construction, provided electricity generation is based largely on renewable or low-CO 2 resources (Swiss power supply mix). The targets are substantially harder to meet where mainly fossil-fuel-generated electricity (European supply mix UCTE) is used.