Life cycle assessment model applied to housing in Chile

Abstract

Complying with international agreements regarding environment, and particularly the reduction of greenhouse gases emissions, requires appropriate policies in the building sector. This study concerns single family housing in Chile. The aim of this work is to develop knowledge in order to define and prepare implementation of design procedures to minimize the environmental impacts without reducing the level of comfort in such buildings. The model presented is based upon the life cycle assessment methodology. Buildings are described including geometry and technological elements. Thermal simulation is used in a first step to evaluate heating and cooling loads, and to check the level of indoor comfort in summer. The results constitute an input to a life cycle simulation tool, integrating the fabrication of materials, construction, use of the building, maintenance and end of life. Environmental indicators like the global warming potential are evaluated. Other indicators concern air pollution, natural resource consumption, waste production etc. This model has been adapted to the Chilean context, particularly regarding the electricity production mix and climatic conditions, considering four climate zones characteristic of the country. In each zone, a typical social housing unit is defined and the corresponding environmental impacts are evaluated. Various technical and architectural solutions are studied, particularly: increased insulation thickness (applying thermal regulation), orientation of windows and glazing types. The performance improvement is higher in cold climates. A reduction of CO2 emissions up to 50% is estimated, and other technical measures are suggested to improve the performance further. According to these results, reducing energy related impacts does not increase other damage indicators related to e.g. human health and biodiversity.