Reducing greenhouse gas emissions while adapting cities to the consequences of climate change is one of the major challenges in the current energy transition towards a nearly carbon-free built environment. A pressing concern regards the rising of global and urban temperatures, which are expected to increase demand for building cooling and hinder the achievement of decarbonisation goals also in continental climate zones. However, available studies and assessment methods still largely overlook the environmental impacts of cooling measures in future climate conditions. This study investigates the efficiency of implementing passive cooling measures (insulation, triple glazing, solar shading, solar reflectivity of façade and natural ventilation) during the renovation of a Swedish multi-family residential building. Novel indicators and an integrated assessment method are developed by combining a climate and energy model with a carbon footprint assessment to evaluate the carbon efficiency of the measures. The results comparison between a baseline case and applied passive measures for Representative Concentration Pathways RCP4.5 and RCP8.5 in 2018, 2030 and 2050 indicates that natural ventilation, triple glazing and solar shading ensure cooling demand reduction between 13% and 56% and have the lowest carbon footprint among the assessed passive strategies. Implementing a combination of all assessed measures has the largest cooling demand reduction potential but poses a trade-off in terms of carbon footprint.

To bridge the gap between the conceptualisation and implementation of circular value propositions, recent research efforts have focused on linking design-driven approaches with circular-oriented innovation. Such approaches can facilitate iterative processes that emphasise co-creation, prototyping, and real-life experimentation, ultimately promoting practical implementation. Still, there is a lack of understanding how companies go through the process of circular-oriented innovation, and how prototyping and co-creation support this process. This article presents a longitudinal case study of a four-year research project in which two academic teams, from Sweden and the Netherlands, collaborated with industrial partners to explore the potential of circular economy principles within the kitchen industry and develop a market-ready circular kitchen. The results indicate that prototyping plays a supportive role in the circular-oriented innovation process by making the concept of a circular economy tangible for stakeholders, facilitating knowledge exchange, and supporting overall developments towards collaborative circular supply chains. However, prototyping too early in the process linked to project deliverables carries a risk for ‘prototype fixation’, fragmented solutions, and missed opportunities for shared value creation. Co-creation was found particularly impactful during the early stages of circular-oriented innovation where it helped guide the project, enabled shared learning, built confidence and commitment amongst stakeholders, and supported the development of solutions tailored to demands of parties involved. The case study provides deeper insights on the role of prototyping and co-creation through diverse stages of the circular-oriented innovation process and extracts several lessons that might aid researchers and practitioners to navigate future circular-oriented innovation endeavours.

The transition to a Circular Economy (CE) requires designers to, more than ever, concurrently develop a circular design, supply chain and business model, and anticipate how products and buildings function over time. To address these challenges, recent studies identified specific knowledge and competencies for designers. However, it remains unknown to what extent future designers (students) are prepared to address the CE in design practice. Therefore, this study investigates how architecture students currently interpret the CE concept and whether that aligns with how they apply the concept in a design assignment. For two years, a workshop was organized with a total of 320 architecture students. The students utilized a card-based circular design tool to conceptualise circular solutions for cases varying in scale and context. According to the students, the main challenge of design for a CE relates to holistic perspectives and systems thinking. The students associate the CE strongly with the reuse of existing (waste) materials, yet results of the design assignment show holistic and diverse approaches of incorporating CE principles. The study identified slight discrepancies between experienced challenges and reported necessary knowledge of designing for a CE, which could relate to the changing role of architects in a CE.

The transition towards a Circular Economy (CE) in the built environment is crucial to achieve the Sustainable Development Goals (SDGs). Theoretical frameworks and methods for circular design have been developed. Yet, there is a lack of knowledge on circular design in practice and how circular design thinking can be supported. This study aims to provide insights on circular design in practice and how this can be supported through circular design methods. First, we reviewed existing circular design methods and developed a card-based circular design tool. Next, an interactive survey and design workshop using the tool was carried out with 12 design experts to gather knowledge on circular design in practice. Finally, we derive key learnings that can support the development of circular design methods and advancement of CE in practice. Overall, circular design remains highly conceptual and is challenging due to the interconnectedness of parameters and temporal aspects such as product life cycle. Designers need ways of educating and convincing stakeholders on the value and feasibility of circular design. Advancing the CE in practice requires circular design methods that help to contextualize the design process and reduce complexity, and examples are needed of how CE can be implemented in practice.