Niveles de sostenibilidad de la madera como material de construcción.

Abstract

Traditionally, timber has been considered an ecological material useful in sustainable construction. It is clear that trees have an environmental role, but the question is: To what extent is the ecological nature of a tree maintained when it is transformed into timber for construction? This transformation implies the incorporation of energy, the use of pollutants, and transport. Thus, waste is generated. We tracked the life cycle of a timber facade evaluating CO2 emissions derived from processing the timber and comparing them with the content of CO2 of the timber in its natural state. On the first stage of the study, the emissions of CO2 believed to be normal for the content of carbon in the timber in its natural state were measured. We obtained a negative value until the timber was used for construction. This means that the emissions of CO2 remain lower than the content of carbon in the timber. On the second stage, the values of the CO2 emissions were positive because they exceeded the amount of carbon contained in the timber. Therefore, wood is no longer a net carbon sink. It is worth noting that higher CO2 emissions are due to heat used to dry the lumber and to press and glue plywood and cross-laminated wood. In this study, we considered a mixed energy profile that involves the use of fossil fuels and alternative energy sources. Finally, we propose a scenario exclusively using alternative energy sources and making comparisons with the conditions considered at the beginning.