Re-use of Building Products in the Netherlands

Over the years, the consumption of materials for construction exceeded more than half of the total materials consumed in the Netherlands, and construction waste exceeded the volume of solid waste produced by households. Since the introduction of the "Ladder van Lansink" (in the 1970’s) and the further development of the European Waste Framework Directives followed by the Circular Economy concept, waste prevention has been considered a priority measure. Whereas the goals to improve waste management towards waste-to-resource and waste elimination evolved from guidelines to political action (throughout the EU), reuse of products remained a less implicit strategy. The reuse of building products is an ancient practice; nonetheless, limited information is available regarding the aspects involved in the existing process. Reuse of building products has seen limited regulatory changes and remained a vague procedure within the resource efficiency discourse in the Netherlands. Building products remain in use for long time spans, which affects the planning and integration of strategies to recover them for reuse. When they are released from buildings (after renovation or demolition) and recovered, these products may not be compatible with new updated technical building requirements, or may not be competitive with upgraded, certified and cheaper new products. The weight, size, and practical challenges to deconstruct buildings are also factors affecting the harvest of such products. Besides these technical and economic aspects, used goods are susceptible to subjective evaluation regarding their "style" and used appearance. Contrary to different forms of waste treatment that transform used products into commodities; used products have intrinsic cultural, historical and aesthetic values influencing their economic value. To foster the integration of industrial activities to promote more efficient use of resources from the anthropogenic environment, it requires a better understanding of the constraints and opportunities among relations within a non-linear economy. This research departs from the desire to understand the practice of reuse of building products from a systemic standpoint, to illuminate its current condition and help to foresee future perspectives. System The holistic approach in this research implies the investigation and representation of a network of multiple factors influencing the process of reusing in analogy to the nature of sustainability as a systemic concept that infers a holistic construction of different conceptual subsets. To perceive the continuity of the strategy of reuse, this research positions the object of study from an evolutionary perspective where relations condition the action of reuse. These relations are dynamic and contextually bounded defining the commercial feasibility of products to be reused rather than wasted. Understanding these relations enables to construct an analytical discourse that takes into consideration a multidisciplinary approach from which different strategies can be designed while contemplating their connectivity. From a pragmatic research tradition, the central research question explored is: What are the perspectives for reuse of building products from the housing stock, given contextual factors that influence the process chain and reserves? The Industrial Ecology concept provides a system’s perspective and the foundation of this study’s methodological framework to answer the main research question. It postulates that the internal relations of the industrial process, as well as relations that go beyond the industrial boundary, are sources of perturbations in the natural system, which is driven by human activities and motivate changes in material and substance flows by demand for services provided by products. Through this systemic perspective, to effectuate reuse of building products in the Netherlands, this research proposes to examine this practice as an industrial ecosystem. It describes the activities; actors and how different factors influence the process of building products' reuse. This research is the result of a collaboration between the Faculty of Industrial Design Engineering and Architecture and the Built environment of TU Delft to construct a multi-scale scope ranging product thinking and regional resource management. The investigation departs from the following assumptions: Reuse of products brings environmental benefits. This study does not evaluate which conditions and what are the environmental benefits of reuse. Nonetheless, the study acknowledges that not one-measure fits all, nor that reuse is the best measure in all contexts. The study departs from the premise established by existing guidelines in waste management and the CE (Circular Economy) concept that waste prevention including reuse should be prioritized. Assessing singular aspects of reuse can lead to limited or partial interpretations, risking future ineffective action plans or their complete absence. The practice of reuse is inferred in this study as a cluster of activities that co-exists with other clusters of activities (recycling industry, technological evolution of construction systems and product innovation, waste management, lifestyle, environmental education, policy, primary resources among others), and that changes occurred in each of these parts can also affect the performance of reuse. Single focus analyses are needed but complementary to the holistic approach to increment knowledge and verification of findings. The Industrial Ecology concept is used to emphasize the relevance to develop a systemic vision of reuse. The approach developed in this research exposes the connectivity between different factors and activities within the process and illuminates how these activities are performed. As result, different paths could be designed to improve the performance of the system. Description of the existent practices can help sharpen the understanding of the waste prevention of building products among scholars, practitioners, and policymakers. This research departs from the observation of the existing practice of reuse in the Netherlands to develop a tangible form of analysis and representation of the phenomena in the real world. The research contributes to the waste prevention and management debate, the possible conceptual vagueness, lack of detailing and transparency of what reuse consists, and how waste prevention is equivocally related to curbing economic growth. It also adds knowledge to the concerns of building a systemic approach for a CE exposed by previous scholars. Research structure A design-based research framework is applied to articulate how the study was performed. The analysis was divided into two main parts: The organizational, socio-economic and technological aspects of building products reuse. This segment examines internal relations of the industrial system of reuse, comprised by a description of the organization of activities and actors involved that characterize the supply chain and the practice of commercial reuse of building products in the Netherlands. The relations that go beyond the industrial boundary are clustered by the social, cultural economic, and technological factors influencing how building products are harvested from the building stock for consumption. Conventionally, natural systems are assessed regarding the impact caused by industrial activities or the availability of resources to supply these same activities. As the anthropogenic environment evolves, it is relevant to comprehend how fit the industrial system is in this dynamic context, leading to the second part of the study: The evolution of the housing stock as dynamic reserves (supply of reusable products). The industry of reuse, by analogy, relies on the evolution of the building stock to supply the consumption of reusable building products. To exam this relation, the study investigates what products are commercially reusable (present). These products are a reference to the examination of the housing stock evolution (reserves), which affects the supply of reusable products in speed, composition, and amount of products released from the stock. Finally, the research methodology delimits the industrial ecology of reuse as the sum of different relations influencing the flows of products harvested for commercial transactions of used building products. The representation of this network of relations reveals vulnerabilities and potentials in the industrial system to support future effectuation and evaluations for practice and policy. The conceptual model proposed is a map, a tool to assist the formulations of plans and tests in the learning curve to systematically implement waste prevention measures in the Netherlands. Findings The following limitations guided the mixed methodology proposed in this study: Scarce information about the practice of building product reuse in the Netherlands including social demand for used products; the availability of hard numeric information in waste prevention and periodic consumption of building products for housing construction; the metabolism of the building stock in the Netherlands including information about the survivability and obsolescence of houses as well as periodic physical description of housing the stock at the product level and building sizes. In the first part, the research process was based on literature review, surveys and semi-structured interviews with practitioners in product reuse, experts in construction waste management, governmental agencies and designers. The central object in this stage is the representation of the industrial system of reuse connected to several relations that influence its performance. The key findings in this segment were: Organizational The practice of reuse currently functions as an appendix of the demolition industry, bringing benefits as well as disadvantage