Life Cycle Assessment of Coated and Thermally Modified Wood Façades

Abstract

Façades—their design, aesthetics, performance, type of cladding material, and understructure—determine architectural expression and form unique appearances of individual buildings. In connection to the sustainable development idea, wood façades provide one of the alternatives of a contemporary building exterior look. Façade cladding made of coated and thermally modified wood can be successfully used for these buildings. In addition, thermally modified wood allows the use of local European wood species, while keeping cladding elements relatively thin. On the other hand, wood has certain structural limitations and disadvantages due to the properties of wood. The main weakness is caused by the surface durability of wood and its related need for maintenance over time. The scope of the study was a comprehensive assessment of coated non-heat-treated and thermally modified wood façades, performed in terms of life cycle assessment. The aim was to identify which type of wooden façade had the lowest environmental impact. According to the EN 15804 + A2 standard, the principle of evaluation of environmental parameters “cradle-to-gate-with options” was used to evaluate wooden façades and coatings and surface preservation methods. Simulations with the SimaPro program showed that the thermal modification of wood has a significant impact on the environment at the product stage. Nonetheless the thermally modified façade without any surface coating showed the lowest environmental impact in a 30 year time-horizon of the “use stage”. It was showed that surface maintenance methods applied, the coatings used, and the frequency of their application play an important role in the environmental impact of the investigated wooden façades.