Using Life Cycle Assessment in tenders to enhance the sustainable procurement of External Thermal Insulation Composite Systems

Abstract

Green Public Procurement (GPP) is a policy instrument to decrease the environmental impact of products and services and create environmental value for society. A new method for assessing environmental award criteria in GPP processes was developed to integrate environmental and economic criteria into public tenders for External Thermal Insulation Composite Systems (ETICS). The main objective of this study was to identify the effect that the inclusion of environmental impacts can have on decision-making in public procurement. At this scope, an environmental benchmark for the main phases of the supply chain (production, installation and disposal) of ETICS that use different insulating materials, including EPS and mineral wool, was defined for different Life Cycle Assessment (LCA) impact categories after a detailed literature review. Then the monetisation method of the externalities was applied to combine the environmental impacts and the direct costs associated with the manufacture of the ETICS system by obtaining a single score for the selection of the best bid from the environmental and economic point of view. This methodology was implemented in a spreadsheet and a case study was analysed as a practical application of the tool developed for the determination of the global index. The case study simulated a tender in which three contractors provided their bid for an ETICS system. The overall investigation of the results obtained in the case study showed that the environmental externalities have a rather limited incidence compared to direct costs (between 0.8 and 10%). However, even if the lower direct costs were provided by contractor 1 (87.72 €/m2) in comparison to contractor 2 (87.80 €/m2) and contractor 3 (92.74 €/m2), the slightly higher environmental impacts caused the costs to rise. The most environmentally and economically advantageous bid was then provided by contractor 2, for which the global index was the lowest for each monetisation method applied. For all the impact categories considered, the production stage (A1-A3) represents the most significant contribution. The thermal insulation material and the finishing coat provide the greatest contribution to the environmental impact. The tool was designed to improve the knowledge of the economic and environmental performances of ETICS systems, which might be also used by public administrations to define minimum environmental requirements and maximum specific costs when preparing tenders for the energy requalification of buildings.