Timber-based Façades with Different Connections and Claddings: Assessing Materials’ Reusability, Water Use and Global Warming Potential

Timber-based façade technologies have the potential to effectively reduce the carbon footprint, reduce water use in construction, and minimize waste, when their manufacturing process is highly prefabricated. Additionally, avoiding glue parts can enhance the sustainability of the façade as its elements can be replaced (extending the durability of façades and therefore buildings) and separated once that they reach their end of life (to re-use or recycle them). Thus, the connection between materials might have a considerable impact on the façade’s sustainability. Moreover, timber-based façades can have different claddings, impacting on the water needed for the technology and their Global Warming Potential (GWP). This paper assesses, through a novel methodological approach, materials’ reusability, water use, and GWP for different façade connections and claddings. Four prototypes with different connections (staples, screws, timber nails, and geometrical assembly) were built. Experimental activities representing façade elements’ substitution and disassembly provided qualitative and quantitative information about production, extraordinary maintenance, and end-of-life phases. Through these tests, the quantity of material that could be re-used and disposed in such phases was quantified and then inserted in a Life Cycle Analysis (LCA). LCA was conducted using EF v.3.0 impact method and components were modelled with EPD information and Ecoinvent cut-off 3.7 database. According to the results, a timber-based façade with timber nails and wood cladding is the most promising of reusable façade materials, decreasing the water use and GWP.