Creating a Resource Cadaster—A Case Study of a District in the Rhine-Ruhr Metropolitan Area

Spatiotemporal tracking of building materials and their related environmental impacts

Urban development will increase the demand for new buildings expected to cause significant environmental impacts in the coming decades. Spatiotemporal prediction for new buildings, their typologies, resource quantities and types required for construction, and the associated impacts are crucial to effectively tackle strategies to reduce the related greenhouse gas emissions. Within the context of Denmark, this study establishes a prognosis of expected yearly embedded impacts across the country towards 2050 based on Business as Usual (frozen policy) trends. Through the Holt-Winters method's additive version, the study forecasted the future amount of building types in each Danish municipality. The embedded impacts disaggregated into building types, components, materials, and life cycle stages are calculated from the material intensity coefficients of real projects. Considering a 'business as usual' scenario, the prediction shows an increase in demand by 6.5 % for new gross floor areas compared to the number of current buildings constructed in the past years. The GHGs from the upstream processing of materials correspond to 7 % of current consumption-based yearly emissions in Denmark. To strive for sustainable development, the findings of the study help inform stakeholders in the built environment to better correlate the material mechanism 'supply-demand' for circularity and where efforts to minimize the impacts should be prioritized.

Circular economy in Brazilian construction industry: Current scenario, challenges and opportunities

The effective implantation of the circular economy (CE) presents a great challenge to the industrial sectors, mostly in those of greater environmental impact, such as construction industry. In Brazil, this industry has been growing over the last 20 years; however, such growth was based on an extractivist economy without any consideration to the end of its products lifespan. Only in 2017, 45 million tonnes of construction and demolition waste were generated in the country. This paper presents the current context of public policies in the Brazilian construction industry and proposes initiatives to introduce principles of CE. An exploratory study was developed, and all the 45 references presented in Appendix A of the review paper of Benachio et al. were considered to draw new ideas. These ideas are related and compared to key points in Brazilian regulations. Twelve opportunities for the improvement are listed and organized by construction stages (planning and design, materials manufacturing, construction processes, use and demolition). The ones related to design and planning using Green building information modelling, and materials manufacturing with recycled waste are highlighted due to the existing actions, standards, and Federal legislation. It was found that some sectors and the government already have actions related to CE (based on the 3R principle), but still there are several initiatives needed for its effective implementation in the Brazilian construction industry.

Mining the Built Environment: Telling the Story of Urban Mining

Materials are continuously accumulating in the human-built environment since massive amounts of materials are required for building, developing, and maintaining cities. At the end of their life cycles, these materials are considered valuable sources of secondary materials. The increasing construction and demolition waste released from aging stock each year make up the heaviest, most voluminous waste outflow, presenting challenges and opportunities. These material stocks should be utilized and exploited since the reuse and recycling of construction materials would positively impact the natural environment and resource efficiency, leading to sustainable cities within a grander scheme of a circular economy. The exploitation of material stock is known as urban mining. In order to make these materials accessible for future mining, material quantities need to be estimated and extrapolated to regional levels. This demanding task requires a vast knowledge of the existing building stock, which can only be obtained through labor-intensive, time-consuming methodologies or new technologies, such as building information modeling (BIM), geographic information systems (GISs), artificial intelligence (AI), and machine learning. This review paper gives a general overview of the literature body and tracks the evolution of this research field.

Circular Digital Built Environment: An Emerging Framework

Digital technologies are considered to be an essential enabler of the circular economy in various industries. However, to date, very few studies have investigated which digital technologies could enable the circular economy in the built environment. This study specifically focuses on the built environment as one of the largest, most energy- and material-intensive industries globally, and investigates the following question: which digital technologies potentially enable a circular economy in the built environment, and in what ways? The research uses an iterative stepwise method: (1) framework development based on regenerating, narrowing, slowing and closing resource loop principles; (2) expert workshops to understand the usage of digital technologies in a circular built environment; (3) a literature and practice review to further populate the emerging framework with relevant digital technologies; and (4) the final mapping of digital technologies onto the framework. This study develops a novel Circular Digital Built Environment framework. It identifies and maps ten enabling digital technologies to facilitate a circular economy in the built environment. These include: (1) additive/robotic manufacturing, (2) artificial intelligence, (3) big data and analytics, (4) blockchain technology, (5) building information modelling, (6) digital platforms/marketplaces, (7) digital twins, (8) the geographical information system, (9) material passports/databanks, and (10) the internet of things. The framework provides a fruitful starting point for the novel research avenue at the intersection of circular economy, digital technology and the built environment, and gives practitioners inspiration for sustainable innovation in the sector.

Quality assurance in reverse logistics supply chain of demolition waste: A systematic literature review

The reverse logistics supply chain (RLSC) facilitates the greening of the traditional construction industry supply chain. Despite the growing interest in this approach, limited studies focus on quality assurance (QA) in RLSC, which is crucial to resolve the issue of the low quality in reprocessed products. This study aims to explore the elements which contribute to the QA of RLSC of demolition waste (DW) by conducting a systematic literature review (SLR). A total of 91 articles available in six search engines between 2000 and 2019 were exposed to descriptive and content analysis. The descriptive analysis revealed that most of the articles were experimental studies (35%) and published during the recent period of 2013-2019 (64%). Furthermore, 60% of articles were originated from developed countries while 32% originated from developing countries. The results of the content analysis established that an information-centric integrated system of process, people, policy and technology is needed for QA in RLSC, which is supported by government, regulatory bodies, industry and universities/research institutions. The study addresses the existing gap by proposing a conceptual framework, which could be considered as the foundation in enforcing QA in the RLSC of DW. Finally, the implications for research and practice and some recommendations for further research were presented. The study facilitates in paving the path to sustainable development through building the foundation to enforce QA in RSLC of DW.

Clean construction and demolition waste material cycles through optimised pre-demolition waste audit documentation: A review on building material assessment tools

Waste from the construction sector poses huge challenges for sustainable waste management. This is not only due to the vast amount of waste produced in construction and demolition activities, but also due to pollutants potentially contained in these products. Subject to these conditions, waste management must ensure recovery of as many resources as possible, while making sure to keep material loops clean. This demanding task requires more knowledge about the existing building stock and an adaptation of current demolition processes. Innovative technologies, such as Building Information Modelling, or modern frameworks, such as Geographic Information Systems, offer a high potential to synoptically provide stock material information for future demolition activities for individual objects to be deconstructed as well as for whole cities as a basis for managing the anthropogenic stock and potential urban mining. Suitable methods of data collection allow for acquiring the desired input for the generation of building stock models enriched with demolition-related information. With the latter, selective deconstruction strategies as well as appropriate waste stream routing agendas can be planned and executed, thereby securing safety at work during the demolition process itself and a waste stream routing according to the waste hierarchy. This review article gives an overview of currently deployed building material assessment tools (data capture and visualisation), both a prerequisite for improved information on materials and geometry (and thereby mass/volume). In addition, this article describes workflows employable for the purpose of urban mining in end-of-life buildings, of which one holistic approach will be described in depth.

High-Resolution Mapping of the Urban Built Environment Stocks in Beijing

Improving our comprehension of the weight and spatial distribution of urban built environment stocks is essential for informing urban resource, waste, and environmental management, but this is often hampered by inaccuracy and inconsistency of the typology and material composition data of buildings and infrastructure. Here, we have integrated big data mining and analytics techniques and compiled a local material composition database to address these gaps, for a detailed characterization of the quantity, quality, and spatial distribution (in 500 m × 500 m grids) of the urban built environment stocks in Beijing in 2018. We found that 3621 megatons (140 ton/cap) of construction materials were accumulated in Beijing's buildings and infrastructure, equaling to 1141 Mt of embodied greenhouse gas emissions. Buildings contribute the most (63% of total, roughly half in residential and half in nonresidential) to the total stock and the subsurface stocks account for almost half. Spatially, the belts between 3 and 7 km from city center (approximately 5 t/m²) and commercial grids (approximately 8 t/m²) became the densest. Correlation analyses between material stocks and socioeconomic factors at a high resolution reveal an inverse relationship between building and road stock densities and suggest that Beijing is sacrificing skylines for space in urban expansion. Our results demonstrate that harnessing emerging big data and analytics (e.g., point of interest data and web crawling) could help realize more spatially refined characterization of built environment stocks and highlight the role of such information and urban planning in urban resource, waste, and environmental strategies.

Developing an Urban Resource Cadaster for Circular Economy: A Case of Odense, Denmark

The significant amount of secondary materials stocked in products, buildings, and infrastructures has directed increasing attention to urban mining and circular economy. Circular economy strategies and activities in the construction industry are, however, often hindered by a lack of detailed knowledge on the type, amount, and distribution of secondary materials in the urban built environment. In this study, we developed such an urban resource cadaster through an integration of the geo-localized, bottom-up material stock analysis with primary data on building material intensity coefficients for a case of Odense, the third largest city in Denmark that is undergoing major construction works. We quantified the total amount and spatial (including vertical) distribution of 46 construction materials stocked in buildings (residential and nonresidential), roads, and pipe networks (wastewater, water supply, and natural gas). In total, 66.7 megatons (or 329 tons per capita) of construction materials are stocked in Odense, in which aboveground stock only makes up for a third of the weight but hosts a wide variety of materials. This urban resource cadaster at high resolution can inform a variety of stakeholders along the value chain of the construction industry to better plan for construction materials and component recovery and smart waste management.