**Charlotte Cambier 1,\*, Waldo Galle 1,2 and Niels De Temmerman <sup>1</sup>**


Received: 30 June 2020; Accepted: 12 August 2020; Published: 18 August 2020

**Abstract:** To support the construction sector in its transition to a circular economy, many design instruments and decision support tools have been and are still being developed. This development is uncoordinated and raises confusion among building designers and advising engineers, slowing down the tools' adoption in practice. Moreover, it is unclear if the available design tools are able to fulfil the needs of design professionals at all. Therefore, this research identifies the knowledge challenges for the "supply and demand" of design tools for a circular construction practice. It focuses on Flanders, given the importance the topic receives in the region's policy programme and among practitioners. This study builds on a thorough literature review, and on inventorying and categorising instruments and ongoing developments. By comparing that review with the needs that were identified during interviews with a focus group, it was possible to pinpoint designers' needs for support tools and outline three urgent research tracks. More generally, it was found that the needs of our focus group are only partially reflected by the available design tools and the ongoing developments. This identified mismatch advocates for a more participatory and practice-oriented research approach when developing design support tools for circular building.

**Keywords:** design for circularity; design support tools; circular construction; circular economy
