Using recycled aggregates has many positive environmental impacts because of the conservation of natural resources and minimization of waste. The use of recycled aggregates in downcycling processes is already common in Germany, whereas utilizing them to produce high-quality recycled concrete is rarely applied in practice. The reasons behind this lag have been investigated based on surveys and interviews with stakeholders. Miscommunication and missing information were identified in all stakeholder groups. Therefore, establishing a robust network and facilitating knowledge transfer by specifying the demand for recycled aggregates in the case study region have been considered as prerequisites. Therefore, the paper presents a novel concept of a stakeholder network for an integrated construction and demolition waste center. The conceptualization integrates the recycling companies and construction product manufacturers in one venue with research, service, and educational divisions. The design of the facilities is based on calculations regarding future construction activities and the demand for concrete production. The proposed concept aims to supply the region in the west of Germany with high-quality recycled products while also establishing a robust network that offers benefits in terms of logistical optimization and knowledge transfer.@en

Die offensichtliche Rolle des Baugewerbes beim Klimawandel bestimmt derzeit den architektonischen Diskurs. Historisch gesehen konzentrierte sich die Nachhaltigkeitsdebatte primär auf den Energieverbrauch während der Nutzungsphase von Gebäuden, seit die Politik in den 1970er Jahren Energieeffizienzbeschränkungen eingeführt hat, was zu einer verbesserten Energieeffizienz während dieser Phase führte. Wenig Fortschritt wurde jedoch bei der Herstellung und dem Abriss von Gebäuden erzielt, was zu einem immensen Verbrauch von globalen Ressourcen, einer hohen Produktion von Abfall und einem bedeutenden Anteil an globalen CO2-Emissionen im Bausektor geführt hat [1]. Infolgedessen besteht eine moralische Verpflichtung für die Bauindustrie, Ressourcen zu erhalten und ihre Auswirkungen auf die Umwelt auszugleichen.@en

The construction industry, accounting for a significant portion of energy consumption and greenhouse gas emissions, is pivotal in achieving Europe's ambitious climate neutrality goal by 2050. Circular Economy (CE) principles and the renovation of existing buildings are identified as promising strategies to reduce raw material and energy consumption. However, the lack of knowledge and guidelines for effective CE design and construction in the built environment, along with heterogeneous metrics and standards, pose challenges. The research outlines an investigation study aimed at developing Key Performance Indicators (KPIs) for evaluating building products based on CE principles, focusing on façade renovation. The study emphasizes the need for a holistic approach, considering both material input and output flows, and introduces qualitative and quantitative KPIs addressing aspects such as recyclability, modularity, and local materials. The research proposes established frameworks like Life Cycle Assessment (LCA), Material Flow Analysis (MFA), and the Level(s) framework, but recognizes their limitations in assessing circularity comprehensively. The methodology involves a comprehensive analysis of material streams and circularity potential for nine components crucial to achieving a net-zero façade renovation. Results from the material flow analysis demonstrate the environmental impact of selected building products, such as insulation panels and photovoltaic panels. The research underscores the importance of informed design choices, leveraging adaptable KPIs, and visualizing resource flows to enhance decision-making for sustainable construction practices aligned with CE principles.@en

Die Transformation der linearen Wirtschaft hin zu einer Circular Economy birgt das Potenzial, den aktuellen Ressourcenverbrauch und Emissionsausstoß der Baubranche zu reduzieren. Dabei werden ein radikales Umdenken aller am Bauprozess beteiligten Akteure und die Umsetzung von Wiederverwendungs- und Recyclingstrategien gefordert. Geschlossene Stoffkreisläufe führen zu neuen Aufgaben und Rollen, gleichzeitig steigt die Komplexität während der Entwurfs- und Bauphase. Unterstützend wirken digitale Werkzeuge, Fachplanende mit Wissen über zirkuläres Stoffstrommanagement und interdisziplinäre Netzwerke. Denn zukünftig werden Anforderungen an Gebäude bezüglich Ressourcenschutzmaßnahmen steigen. Um wettbewerbsfähig zu bleiben, ist ein ganzheitliches Wissen über Umweltauswirkungen entscheidend.@en

Circularity for Educators’, and a second platform for interaction and direct exchange that we call ‘Educators for Circularity’, are part and parcel of the Circular Impulse Initiative (CII), a project intending to enhance the integration of circularity in BK education. Whereas the first provides with content on either circularity or pedagogy, the latter offers the opportunity for all of us to meet and share our experiences and learn from one another. More than 40 professors and researchers have contributed so far with videos and additional resources that are open and accessible to all. @en

The Urban Mining (UM) approach as part of the Circular Economy (CE) model has emerged as a significant paradigm in the construction industry due to its evident positive impact on the environment. Within the AEGIR project, UM plays a decisive role as the solution will consider components as sources of anthropogenic materials which can be cyclically used, recycled, and reused. Therefore, the processes of reclaiming the AEGIR compounds after their end of life was analyzed and recommendation for optimization in regard to waste and resource reduction were proposed. Task (T) 3.2. designated as ‘Urban Mining Approach to Enhance Sustainability and Circularity of the AEGIR Solution’ aims to achieve the overall goals of the AEGIR solution of low embodied energy, the use of local bio-sourced materials and recycled materials. This goal will be achieved by identifying, mapping, and prioritizing regenerative strategies for handling building components and materials in a circular way. The Deliverable 3.4. entitled ‚Resources with potential to be recovered‘ critically assesses the current material flow of each AEGIR component in terms of primary or secondary material and the availability of resources in the new components and materials with valid circular life strategies following the UM approach. The analysis involves a comprehensive evaluation of the material flow of each product, encompassing the entire value chain such as supply chains, current recycling strategies, and potential for future reuse or recycling. The circularity of AEGIR components will be determined through the implementation of Key Performance Indicators developed in D. 2.3. and Material Flow Analysis as a standardized method. The results will be utilized to collaboratively develop the products with manufacturers. By implementing this approach, the project can effectively utilize existing resource stocks and reduce the resources and emissions associated with the production of new components. In Chapter 3 of the report, results for each AEGIR component are presented. The analysis of the AEGIR solution reveals that certain components already align with the principles of UM. The results presented in this report will serve as a basis for integrating sustainability approaches in the development of a CE roadmap and standardization measures in WP3. In summary, this report focuses on current material flow of components and their potential as future material after their end of life. The AEGIR project aims to adopt circular material flows by applying environmental requirements on components and incorporating CE principles. @en

The construction industry plays a vital role in promoting economic prosperity and sustainability. However, it is also the largest consumer of resources and the largest producer of waste. Therefore, the implementation of circular economy principles in the building sector is crucial. The AEGIR project aims to develop a solution that adopts a clear approach to sustainability and incorporates circular economy principles. A Circular Economy (CE) offers a promising alternative to a linear economy as it seeks to increase the use of renewable or recyclable resources, reduce the consumption of raw materials and energy, and protect the environment by minimizing emissions and material losses. The project's scope is to define and apply circular principles on the material, product, and building levels. The project workflow includes nine work packages (WPs), including the development of concepts, products, and solutions and implementation on pilot cases. WP2 focuses on the overall concept solution design that sets the basis for the different developments. Task 2.3 aims to define the overall concept for circularity as a solution for AEGIR, taking into account various regulations and approaches to circularity established in Europe. As a first step, existing sustainability frameworks were reviewed. The Levels(s) methodology, which provides a set of indicators and common metrics for measuring the sustainability performance of buildings along their life cycle, was explored. The methodology assesses the environmental performance, health and comfort, life cycle cost and value, and potential risks to future performance of buildings. Additionally, the Cradle-to-Cradle model and R-Strategies were introduced as definitions for circularity.@en