Towards sustainable re-construction systems: from waste ruins to eco-efficient buildings

Abstract

Building reconstruction projects are mainly motivated by social factors, without a deep evaluation of the Best Available Techniques. The main aim of this work is to analyze the advantages of defining sustainable retrofitted buildings, previously building the edifice, by using methodologies towards sustainable systems. A real re-constructed building is considered as a case study. Three scenarios are investigated to analyze its sustainability, including the waste ruins of the old building (Scenario 1), the current re-constructed building (Scenario 2), and a hypothetical sustainable retrofitted building (Scenario 3). Firstly, the current energy consumption is studied including heating flow through walls (thermal bridges and condensation risk) as well as operational costs. Secondly, a new scenario is proposed adding passive solutions to this existing building, to improve its energy efficiency; also, energy consumption and costs of the refurbishment are analyzed. Results show that Scenario 1 leads to a bad image of a city involving the environment and social fields. Scenario 2 entails expensive operational costs. On the other hand, Scenario 3 results in approximately 90% of cost savings in heating energy demand, which would be traduced on high economic savings. Taken into account not only economic factors but environmental and social ones, it can be concluded that it is more sustainable and profitable constructing an efficient building from the beginning by using waste ruins and simulation software despite refurbishing a re-built edifice.