The Circular Economy (CE) paradigm has been gaining momentum. However, the tools and methods used to design, measure and implement circularity are not immediately suitable for decision making and practice by key stakeholders. This article details a qualitative and a quantitative method to evaluate characteristics such as circularity, adaptability and reuse of building elements amongst others in order to provide decision-makers, such as building clients, architects, investors and policy makers, an objective way to assess the benefits and constraints of circular buildings and elements. The study implements the method in the case study, the Circular Retrofit Lab in Belgium, and uses a multi-criteria decision approach to evaluate qualitative parameters and life cycle assessment and life cycle costing to quantitatively evaluate the circular solutions proposed in this study. As such, the paper shows how a multi-criteria decision approach can be applied to evaluate circular building solutions in the context of practical architectural projects, in this case assessing the suitability of three interior wall systems for applications with different turnover rates. The study shows that the overall performance of the evaluated wall systems varies largely from one expected user scenario to the other.@en

Living in an age of rapid changes, designers are challenged to create solutions that remain sustainable in a continuously evolving environment. Since most of our earth's resources are finite, these solutions should incorporate efficient material use and reuse. Buildings and structures are always in transition. Facilitating these transformations is vital to the sustainable development of our built environment. With our group we study, develop and assess transformable structures on different scales, in different contexts and for various time-spans and purposes. This paper presents our work on transformable structures, based on four case studies: a kinetic curved-line folding component, a temporary and rapidly assembled structure, a dynamic wall assembly and a BIM tool for material flow assessment of adaptable buildings. Although varying in scale or purpose, these cases demonstrate the same key principles of transformability. Reducing the complexity of the connections and structural system facilitates an easy and rapid assembly, but also allows users and locals to participate in the assembly, maintenance, reconfiguration and deconstruction of the structure. Apart from benefits during the assembly and adaptability, it is important to assess transformable structures and building solutions on their material and cost effectiveness. With BIM tools it is possible to incorporate this assessment already in the conceptual design phases of a project, as illustrated in the fourth case.@en