Is selective demolition always a sustainable choice?

Selective demolition is usually perceived as essential for a sustainable built environment since it aims to maximise the valorisation of constituent building materials and components giving them a new life. The successful diversion of construction materials from landfill and the extent of recovery of construction and demolition wastes as secondary raw materials depend on how the demolition work is executed, as well as on the logistic and economic aspects of the geographic context. The main goal of this study is to critically explore the sustainability of selective demolition practices versus traditional ones by addressing the environmental issues through the Life Cycle Assessment methodology. The key parameters that determine the environmental profile of a selective demolition project and their effects on the overall environmental balance were identified. Primary site-specific data supplied by the demolition companies involved in the demolition of a residential building located in Milan (Northern Italy) were used in the analysis. The results indicate that the environmental sustainability depends a lot on the characteristics of the building to be demolished as well as on the local markets for recycled materials. Moreover, the benefits from substituting primary raw materials can be overset by the increased impacts due to additional energy requirements of the selective demolition in comparison to the traditional one. Consequently, the environmental sustainability of selective demolition should be addressed on a case by case basis.