Assessment of the decrease of CO2 emissions in the construction field through the selection of materials: Practical case study of three houses of low environmental impact

A great quantity of CO2 is emitted to the atmosphere through the different phases of a building life cycle: in the production of materials and products, in the construction of the building itself, in the setting on site, in the exploitation, the renovations, the later rehabilitations, up to the final demolition. The present paper shows the possibility of reducing the CO2 emissions up to 30% in the construction phase, through a careful selection of low environmental impact materials. The purpose of this study is to quantify the total amount of CO2 emissions saved by the method presented in the particular phase of material selection within the life cycle of a building. This material selection, as well as the bioclimatic characteristics, must be defined from the early design project phase. The research presented here has been carried out on a case study of three terraced houses built in Spain, comparing them with a building with similar characteristics but constructed in a conventional way and with no selection of materials. The houses have been constructed following low environmental impact criteria, including alternative energies for future use and maintenance.