Reducing the environmental impact of distribution centres

Abstract

Buildings influence the environment due to the emission of greenhouse gases, energy use, water consumption, and waste generation. The load-bearing structures of buildings also have a significant share in these emissions. Currently, European and national regulations oblige to focus on sustainability in designs as well. In this research, it is therefore investigated how the environmental impact of a specific case study can be reduced (the Base design). This is a distribution centre’s load-bearing structure and is a sway steel structure with one mezzanine floor made from concrete and steel. In the first part of this research, the design choices to reduce the yearly environmental impact of a distribution centre’s load-bearing structure are investigated. This is done by following three circular economy strategies to improve the Base design. The first strategy focuses on the building’s initial material use, where it is aimed to reduce the current impact of these materials as much as possible. This strategy is applied in a non-sway steel structure and a non-sway timber structure. The second strategy focuses on the afterlife of a building. This led to a steel sway structure where Design for Deconstruction is applied, which means that extra attention is given to the connections to ensure reuse is possible at the end of life. The third strategy focuses on extending the use stage, meaning that the design is optimised for multiple functions. This is implemented in two designs where the principle of Design for Adaptability is applied. In the second part of the research, several environmental impact calculation methods to measure the environmental impact are investigated. It is decided to consider the current product impact (Stages A1-A3 of a Life Cycle Assessment) and the final stage (Stage D), where benefits and loads beyond the system boundary are calculated. As a result, the yearly environmental impact is calculated for the different design alternatives and is given in a shadow price (in euros) per year. This is done separately for the main load-bearing structure and the mezzanine floor load-bearing structure. From the environmental impact calculation of the design alternatives, it can be concluded that there are several ways to reduce the environmental impact of a distribution centre. Though, the following design aspects influence this most significantly. Firstly, it is concluded that environmentally friendly material should always be chosen over other materials to reduce the environmental impact of a building. More specifically, it is recommended to design a timber sway structure (Alternative B) if the reference service life of the building is unknown or if a long reference service life is expected. For a short reference service life, it is recommended to focus on the afterlife of a building. This strategy is most effective if this is combined with a reduction in initial material use. For the main load-bearing structure, Alternative A with an end of life scenario with a high chance of reuse results in the lowest yearly environmental impact. For the mezzanine floor, the demountable floor design with a high chance of reuse of Alternative C leads to the lowest yearly environmental impact. Besides, using the building for a longer time is also an effective measure to reduce the yearly environmental impact. The reference service life may extend if a building is designed for multiple functions. This can be assessed by asking the client about their expectations of the use of the building. By assessing this issue in the design phase, it can be decided to include some overcapacity to ensure a longer reference service life.