No abstract

Among the approaches of circular construction, the reuse of buildings can be considered the most desirable as it leaves a large portion of embodied carbon untouched. At the same time, it also minimises the energy effort of modifying, transporting or reprocessing the components. However, its underlying mechanisms and boundaries are largely understudied as convertibility and adaptability are currently at most rudimentary integrated neither into legal frameworks nor the architectural or technical design process in practice. In this paper, a new methodology is presented based on the models of Brand (1995) and Leupen (2006) to describe the adaptability of buildings as a function of their structure. The model also includes the circulation system and the specific areas of use. In the discussion of structurally determined usability, several concepts are introduced, such as structural porosity, pockets of use, diversity of pockets of use and diversity of circulation. The method is applied to three case studies that offer different adaptabilities due to their structural configurations. As the permeability or structural porosity of slabs significantly contributes to the usability throughout the structure’s lifetime, ribbed slabs seem to increase adaptability. Together with the spatial structural porosity of the grid, it proves to be a helpful criterion for good appropriability and convertibility. The method proved beneficial in understanding the dependence of the change of use on a given structural configuration. It helps to name the essential aspects, objectify them and make substantially different buildings comparable.

The reuse of construction components is considered as a higher value process in a Circular Economy (CE) than recycling. However, this is not yet widely adopted as many barriers still prevent the successful integration of the concept. The ISO20887 standard advocates that the implementation of construction standards will benefit circular reuse. Yet, these standards still need to be developed. To better understand the views of the construction sector, a survey was sent to the network of the Green Deal on Circular Construction (GDCC), led by Circular Flanders. The survey (number of recipients = 629, response rate = 16%) investigates the current implementation of Design for Disassembly and the reuse of construction components. Additionally, it investigates the respondents’ view on how a further morphological standardisation of components and connections, as well as standardisation of procedures can facilitate this reuse of construction components. The result is a concrete set of action points and corresponding actors who need to take responsibility. The stakeholders point out that there is no legal framework for component reuse. Yet, this framework can only be created through their largescale cooperation to create the needed construction standards that will truly enable the circular reuse of components.