Environmental assessment of design choices of green walls based for materials combination and plants

Purpose: Green infrastructures have been considered as a sustainable solution to deal with the problems in dense urban spaces. This acceptance has led to the use of various materials and methods in designing and producing green infrastructures. The purpose of this study is to emphasize the components and materials used in the green walls system. By determining the environmental impact of each element, it can be replaced with another component with the same function. This approach ultimately leads to the sustainable design of systems. Methods: Accordingly, two green wall systems were selected for the environmental assessment using the life cycle assessment method. Data related to all processes and components involved in each system are reviewed for a 10-year lifespan. For each system, eight different scenarios of component composition are considered. The functional unit is 1 square meter and the ILCD method is used to evaluate the impact of the life cycle. OpenLCA software and Ecoinvent® v3.7 database are used to model and analyze all 16 scenarios. Results: The results clearly show that the components and materials used in the production and construction of the green wall system have a very high impact on the environmental performance of these systems. A better design can be achieved by doing an environmental assessment, identifying the undesirable components in the system, and replacing them. Different scenarios' results show the potential to improve the environmental performance of systems in all impact categories. This highlights the great importance of the green wall system's design, material selection and maintenance methods. Conclusions: Considering the ability of the LCA method to identify the weak and strong points of the systems, the lack of using this method in the design phase is strongly sensed. With this method's help, it is possible to produce more sustainable systems. On the other hand, the studies conducted in the field of green walls are limited compared to other green infrastructures. At the same time, the design of the green wall system can be changed based on geographical location, weather conditions, access to raw materials and consumer needs. As the number of studies on these systems increases in different places and weather conditions, it can help the stability of these systems.