The circularity principle in the design process of the public client

Abstract

The climate is changing and industries world-wide need to transform to assure a liveable earth for future generations. Within the construction sector, this requires a different approach and perspective on the life-cycle of civil engineering assets since the construction industry and its build environment is the world’s largest consumer of raw materials and responsible for 25-40% of the CO2 emissions. To make the transit to a more sustainable system, an increasingly discussed approach is a shift from the current linear lifecycles to a circular orientated economy. This latter means the preservation of used materials rather than dispose. In this way, the lifecycle loop of the materials is closed and the energy demand and the scarcity of raw resources is reduced. This more circular way of constructing entails the integration of the assets’ end-of-life phase and its’ circular solutions into the design. The reuse of assets, flexibility and adaptability in its’ function, modular based structures and a material database are all possible ways in dealing with assets after their lifetime in a circular manner. The shift towards a circular economy provides the possibilities for reducing the use of primary materials, protection of material resources and reduce the carbon footprint. This enhances a more sustainable practise of the construction industry though asks for major changes in its current operation. Clients play a substantial part in the transition towards a circular construction industry due to their responsibility in the formulation of the scope, project ambitions and requirements in the initiation phase of a project. Rijkswaterstaat, the biggest public client in the Netherlands, has the ambition to tender all the projects climate neutral and circular together with enhancing the sustainable living environment by 2030 and be fully circular by 2050. Circular pilot projects and programs are developed to promote the use of circular principles in the initiation phase, although circularity is currently often seen as an additional feature instead of an integral design principle. This results in a late consideration of the aspect and therefore a low level of circularity. To enhance circularity in projects there is a need for a clear and integral design process that includes circularity and an increase in knowledge among all team members of a project on circularity and the possibilities for the design. The aim of this research is to unite the circularity principles with the design process of hydraulic infrastructure projects and enable circularity to become common practice and a way of thinking. This is accomplished with a framework for implementing circularity in the design process based on state-of-the-art literature and results in a flowchart that aims to guide a project team to consider circularity and its opportunities during the integral design process of an asset. The flowchart visualizes the important development steps needed for the implementation of circularity, together with a circular way of approaching de design of an asset that includes the circular design principles. Thereafter, the public clients’ current design process and practice on implementing circularity is researched in an empirical quantitative study. These findings are reflected against the approach based on literature and show the points of attention for the public client on implementing circularity in the design process. The flowchart is verified with a case study on the project Weir Grave concerning the reconditioning of a historical weir in the river Meuse in the province of North-Brabant. This case study showed that the flowchart is valuable for the implementation of circularity and includes the significant aspects to consider. Although, the flowchart is not yet an applicable chart for design teams due to the high amount of information, layout and English language. A workable version with instructions is realized to improve this. Various barriers accompany the implementation of circularity in the construction sector with the most substantial being the necessary integral character of the industry and design process along with the timing of including the aspect in this process. An integral design method benefits circularity because numerous aspects and lifecycle phases of an asset influence the level of circularity. The integral character also assist the required early consideration of circularity, which is now often considered too late in the design process. Currently, the circular guidelines for the public client are focused on their role as an acquisition party and not on their part in the design. Therefore the design steps for circular assets are not part of the clients’ procedure, although this procedure does influence the possibilities for circularity. Therefore, the public client needs to take circularity into account prior to the tender procedure, in the initiation- and design phase, as relevant decision that influence the possibilities for circularity are made in these phases. This also influences the collaboration with the market party and requires a clear and uniform ambition towards them. Additionally, support, knowledge and an organization wide approach on circularity are of significance when implementing circularity in the design process. This reduces the current risk avoidance culture on circular design and supports the decisions made. One of the most practical measures to enhance circularity in a project is the implementation of the aspect as a requirement from the start in the clients’ internal project assignment and in the tender towards the market to create a responsibility for considering the aspect.