Environmental and economic assessment of dwelling construction in Spain and Chile. A comparative analysis of two representative case studies

Abstract

Countries are placed under high ecological pressure during economic expansion periods, especially in the construction sector. In order to tackle the effects of such expansion, it is necessary to clearly identify its principal sources of impact. In this respect, the present methodology is proposed, where two dwelling projects (one in Spain, where the methodology is initially implemented, and a second in Chile) are economically and environmentally assessed in the design stage. The procedure is based on the Ecological Footprint indicator and the project's bill of quantities, where the latter traditionally classifies project elements into three major categories: materials, manpower, and machinery. Each element has an associated footprint in terms of fossil fuel, cropland, pastures, forest and carbon absorption land, productive sea, and/or built land. The Chilean dwelling has an Ecological Footprint per m2 of floor area similar to that in Spain. The first is mainly built out of wooden materials, while the second is made of concrete and brick. The forest footprint of wooden materials is high compared to the fossil footprint of ceramic materials. The construction cost is significantly lower in Chile than in Spain, due to the cost of construction materials. In the case of the Chilean project, the footprint can be reduced from 0.17 to 0.07 hag/m2, largely due to the use of recycled wood. In Spain, a 25% reduction is achieved by using recycled concrete and steel, and by substituting ceramic vaults with cement vaults. The indicator is sensitive to different building typologies and construction materials, such as wooden, ceramic, and concrete products. The main obstacles in the assessment are related to the classification system of construction work. © 2018 Elsevier Ltd