Environmental impact reduction from using local natural construction materials: case study in the North of Portugal

Abstract

The environmental concerns of the building industry in Portugal have been essentially related with the reduction of economic costs by the energetic optimization of materials production and construction processes. This strategy is focused on using prefabricated industrial materials and maximizing the use of mechanized construction methods. However, with the economic crisis, rising energy costs, rising unemployment and lack of skilled professionals due to emigration, decreased demography and ageing of population, the construction sector faces new challenges. The interest on the refurbishment of existing buildings, as well as on recovering traditional techniques is growing, namely by the use of local less transformed materials in buildings. This paper aims to characterize the availability of inorganic natural materials, such as weathering granitoids for adobe and rammed earth solutions and granite stone in the north of Portugal. The objective is to demonstrate that the use of local natural materials in alternative to conventional industrialized materials can present significant economic and environmental potential related with environmental and economic aspects, using a case study research in the north of Portugal. Considering a reference dwelling with a conventional exterior wall solution in hollow brick, it was evaluated the potential environmental savings of changing the brick of the exterior wall solutions by adobe and granite.