Life Cycle Assessment as a Tool for Low Waste Building Systems, Case Study Building External Wall

Abstract

Life cycle assessment (LCA) is defined as decision making method for buildings from “cradle to grave”. Considering the fact that the construction industry produces 38% of total waste and 40% of total CO2 emissions and uses 50% of all natural resources, according to EIB 2015, the building industry has to change this way of thinking to the concept “cradle to cradle”. According to European Commission (Directive 2008/98/EC 2008), the first and preferred option is waste prevention and the second option are other types of recovery. The waste should be prevented in the design phase and LCA should help a lot in this stage. The main goal of this paper is to show how the LCA can be used as a tool in design phase to help decision process in building design of one of the building systems and make that part circular and, if possible, without waste. External wall, as one of the systems of a building, is taken as case study in its different materialization to show LCA use in the construction waste elimination in building practice. The external wall is the system of a building which is the most exposed to external factors, as weather conditions and human. Very often, the wall is damaged before other systems of a building. Hence the design and building of external walls that produce less waste, is a huge step in construction waste management. The LCA software is used to compare two chosen case studies. The first one is prefabricated wooden wall for low energy houses. The second one is the wooden wall made for Green Design Centre in Mostar in 2018. The first results show that in the second case study, the wall made for reversible and transformable building, and designed according to circular building principles, has better chances to last longer, and produce less waste during its transformations and aging. The paper shows main principles for designing the low waste wooden walls and also some remarks how to upgrade the software to be more helpful in the design phase of the wall systems.