Case description

Design phase

To create a circular building the starting points mentioned before can be formed into four strategies. These strategies (table 6) are reduction, synergy, production, and management. These strategies are derived from seven base points of creating a circular economy and are hierarchical (DCBC, 2018). By applying these four strategies on the focus points of material and energy the circularity of the mall is increased. The focus will be placed on materials and human culture. Materials To reduce the most of materials usage an investigation must be completed that shows the importance of the new construction. In this consideration, other sustainable solutions must be included, and the decision must contain an explanation that indicates that this was not an option. Secondly, the designer must consider the need for the total volume of the building and must be aware of the option to limit this volume (DCBC, 2018). Examples of this could be: • Can the users take advantage of nearby facilities to reduce the amount of space? • Can the multiple users share the available space (e.g., meeting rooms)? • Can the users work with new organisational concepts (e.g., flex workers)? • Optimising the available space. • Reducing the oversizing. After the first steps, a conclusion can be made that a new building is necessary. If this is the case, the first strategy can be applied to reduce the number of materials used even further. Three design concepts are suggested for this purpose. These design concepts are originating from Table 4 in the previous chapter. The first design concept is to design with flexibility in mind. By implementing flexibility in the original design, the building can be transformed during its lifetime to a new purpose. It extends the lifespan of a build and thereby reduces the number of materials used for that project. The second design concept is to design with adaptability in mind. By implementing adaptability, the designer creates a design that can be changed according to the demand of the future. This new demand could arise from a change in the climate, weather, heat, and surroundings. By applying this concept, the building would not require a large transformation to meet the new standards thus saving materials. The third design concept is to design

Reduction

Synergy

Production

Management

The first step is to reduce the demand for products. Research has shown that this step has the largest impact on the reduction of resources. Also, many resources can be saved by having an intelligent design that optimises the amount of space. After the demand for resources is reduced by the first step. The second step is to use the wasted resources from the surrounding area. This relates to water management, heat management and the use of materials from demolished products. Only after exhausting the locally available resources can new resources be created. These new resources must be sustainably created, are created from reused sources, are locally fabricated and are created from ecological sources. The last step is to create a feedback loop to optimise the system. This should contain information about the change in the behaviour of the users and the demand for resources during the operational phase.

Table 6: Four strategies of circularity (DCBC, 2018) a demountable building. A demountable building does not limit the number of materials used during the lifespan of the building, but it does make it relatively easy to reuse the elements.

Culture and society These two values are essential for the built environment, and buildings can positively influence diversity. It is crucial that in the design of a building not only materials are selected that have the lowest impact during its lifetime but also contribute to cultural heritage preservation. It is also relevant that space is created where functions can be located that mitigate the negative social impact (DCBC, 2018). As part of the redesign challenges, the aspect of materials, energy and culture and society and the corresponding design solution should be used as a basis from which the new design is created.

Execution phase

The same four strategies are used to implement circularity in the execution phase of the process. The focus in the execution phase will focus on material reduction and the topic of culture and society. During the execution phase, the material cycle should be as close as possible to minimise waste production. It is a part of the first strategy reduction. It can be done by choosing an alternative technique to use a material (DCBC, 2018). An example of this is the 3D printing of concrete. Also, a different application of the material than in the traditional technique can reduce the number of materials needed to create the same element (Weber, 2018). If the needed materials cannot be optimised further, the contractor should look for the materials in existing projects as part of the second step Synergy. The contractor should start looking for whole elements from other projects that can be reused. Examples of this are structural walls and roofs. Secondly, the contractor should look for components. Examples of this are windows, interior walls, and ceilings. In this process, the idea that the materials must be reused again after the completion of the new project should be integrated. It also means that demountable elements can be used instead of the traditional way of building with static alignments (DCBC, 2018). After the point where the materials cannot be extracted from the existing project anymore, the materials may be fabricated. New materials must be created based on the circular principles mentioned in the third step Production. Firstly, if new material is produced then it must be created from sustainable sources. To find out if a material is sustainable, the findings from horizon 2020 can be used. It is an initiative of the EU to provide information about eco-efficient materials (Pacheco-Torgal, 2014). Secondly, if that material is scarce or certified as a critical material, the usage should be minimised. Thirdly, the positive impact the material has on the environment should be maximised (DCBC, 2018). By following these steps, negative effects of the materials are mitigated. Lastly, according to the step management should the materials be documented (DCBC, 2018). This can be done in the form of a material passport mentioned in the previous chapter.