Life Cycle Assessment of Protection Products for External Thermal Insulation Composite Systems

The energy performance and thermal comfort of buildings are decisive factors for users. Thus, solutions such as the external thermal insulation systems (ETICS) that can be installed in either new buildings or buildings under thermal retrofitting, reducing the energy consumption while improving thermal comfort, tend to become mainstream. This paper purposes to quantify the environmental and economic impacts of various ETICS protection solutions to assist in decision-making at the project phase. In this study, products available on the Portuguese market are considered. The protection products considered are hydrophobic agents, biocides, multifunctional, and self-cleaning. The products are compared by type of protection, presenting some of the most impactful components, following a multicriteria analysis of some of those products gathered into different solutions, with the objective of demonstrating the influence of the weights assigned to environmental and economic indicators. Several data-linked problems were identified, such as the quantity and quality of data available for analysis, crucial to their reliability; thus, an index for quality of information was developed in order to compare different products. In the multicriteria analysis, the weights of the sensitivity analysis between environmental and economic indicators highly influence the "best solution"; therefore, stakeholders need to clearly define their objectives.