Life cycle assessment of buildings and electric lighting energy consumptions

Life Cycle Assessment procedures are being used more and more by designers and consultants in the evaluation of the overall environmental impacts of a building throughout its entire life (“from cradle to grave”). Though many studies have demonstrated that the highest impacts of a building are due to its space heating and air-conditioning consumption, the impacts due to the construction phase and therefore the choice of materials, including glazing systems, are not negligible. The University of Perugia is carrying out a research, funded by the Italian Ministry for Environment, on the role of the building sector on greenhouse gas emissions; within this research, methodologies are being tested to help spread the knowledge of LCA procedures in Italy. The paper illustrates the aims and methodologies of LCA studies, and presents - thanks to two different case studies – the contribution of electrical lighting consumption and the influence of an increase (or decrease) of transparent surfaces to the impacts during the entire life cycle of the buildings. Keywords: Life Cycle Assessment, daylighting, electrical lighting, residential buildings, office buildings