## 8 Discussion  
This section discusses the results of the application to the case study using IMM approaches during the design and call for tenders phases, which was presented in the previous section. Regarding the preliminary design phase, the application of the proposed methodology allowed the definition of a precise and complete waste audit and digital material inventory, which supported the planning and optimization of the selective demolition phase. Close-range photogrammetry for field surveys was the easiest and safest survey technique considering the abandoned status and the height of existing facilities [52], allowing for a limited number of on-site surveys and adding the possibility of in-depth analysis in remote mode. Figure 13 compares CDW management and demolition phase planning in a traditional process and considering the proposed methodology. The use of a digital database as a material inventory promoted always available and up-to-date data that were organized and structured in a machine-readable form, thus ensuring data readiness and processability and agile data management [80; 81]. The case study confirmed that the definition of a waste audit allowed to [5]:  
* Support the definition of reuse and recycling practices and the higher quality and easier traceability of waste through the proper identification and separation of materials;
* Plan selective demolition activities with their associated costs of execution;
* Ensure an unbiased competition amongst the participants in the call for tenders that could depend on reliable information regarding existing site and building conditions and demolition costs, allowing them to propose appropriate construction site plans. Figure 12: Total percentages of reused, recycled, and landfilled waste. The selective demolition costs represented 127% of the estimated non-selective demolition ones, clearly highlighting the importance of applying proper waste audits and selective demolition planning. As a matter of fact, if lower non-selective demolition costs had been considered during the call for tenders phase, the actual increased selective demolition costs would have only been identified during the actual demolition phase. This would have caused the necessity of increasing the project budget or could have resulted in disputes between the Public Client and the company, causing time delays or increased costs. Therefore, the correct identification of selective demolition costs is paramount to ensure the proper development of the tender and construction phases. Considering the design phase, the creation and use of a BIM model of the designed buildings allowed the reduction of construction waste and the promotion of waste minimization during design reviews and clash detections between design disciplines, designers, and specialists [39; 42]. In addition, the possibility of defining on-site reuse strategies, in particular by using concrete wastes as secondary raw materials, resulted in savings for the purchase of a considerable amount of new raw materials, with positive results both regarding the project budget and the environmental aspects, fostering local circular economy practices, and demonstrating the concept of waste as a resource [23; 24]. Concerning the call for tenders, the proposed methodology enabled to:  
* Support of the Public Client in including sustainability criteria for the evaluation and scoring of the bids and in analyzing the environmental impact of the bids, while acquiring the necessary competences for proper GPP implementation [11];
* Promotion of the integration of CDW management and minimization, sustainable resource use, and selective demolition procedures among the participants.