A comparative life cycle assessment of ETICS and ventilated façade systems with timber cladding

The aim of this work is to evaluate the environmental impact of different solutions for building facade retrofitting. Based on Sustainable Construction, this study is carried out by applying the Life Cycle Assessment (LCA) methodology based on ISO 14044:2006 standard requirements. A “cradle-to-grave” life cycle analysis is developed for each solution, comprising the extraction of raw materials to the disposal phase, and then a comparative analysis was performed by considering the same functional unit: 1 m2 of building facade for a 40-year time horizon. Four retrofit solutions are assessed: two External Thermal Insulation Composite Systems (ETICS), differing only in the insulation material, expanded polystyrene (EPS), and insulation corkboard (ICB); and two ventilated facade systems with different types of timber cladding, thermally modified timber, and painted timber. The data included in the inventory phase is mostly taken from technical documentation and from the Ecoinvent database, complemented with scientific literature and estimations when necessary. The LCA was performed using the SimaPro software applying both EPD (2018) and ReCiPe 2016 Endpoint (H) methods. Results of this study show that, phase-wise, the production and maintenance of the components materials have higher contribution in terms of environmental impact. On the other hand, by comparing the various solutions, the ventilated facade retrofit solution with heat treated timber cladding is the one that shows the highest environmental impact in almost every single category, whereas the cladding solution with painted timber finish is the one that shows the best environmental performance.