How to build (in) the future? Legitimacy of socio-technical visions in a bio-based construction sector

• We study how actors in the (bio-based) construction sector envision its future. • We analyze how legitimacy affects the collectivization of socio-technical visions. • Legitimacy of a vision functions as a necessary condition for its general validation. • High general validation across all types of legitimacy constitutes a dominant vision. • The selective use of bio-based construction materials is the dominant vision. The use of bio-based materials offers opportunities to mitigate the climate impacts of construction, with buildings potentially acting as carbon sinks. However, it remains unclear what a future bio-based construction sector will look like. One reason for this are diverse socio-technical visions for the use of bio-based construction materials. In this paper, we use discourse analysis across a comprehensive set of expert interviews to pinpoint (competing) socio-technical visions of a bio-based construction sector in China, India, Germany and Italy. Drawing on the sociological literature on legitimacy, we examine the legitimacy of socio-technical visions as a necessary condition for their collective adoption by stakeholders in the sector. It enables us to conceptualize the development and validation of visions, providing a framework for transition studies to track one part of the collective adoption of visions. This, in turn, adds to the understanding of the formation of ideations that potentially influence transition processes.