Circular economy is an economy model aiming to overcome the current linear economy and closing resources loop. Circular economy is still far from being widely widespread and implemented. The transition to circular economy is particularly tough in complex and highly fragmented sectors where information, materials and products’ flows are interrupted multiple times at different stages. Among these complex and fragmented sectors, the building sector stands out given its high resource consumption and emissions. Collaboration is needed to implementation circular economy in the building sector. Indeed, collaboration enables to spot in advance any issues and/or mismatches that may arise along the whole value chain given that the different actors belonging to the value chain jointly collaborate since the starting design phase. We have focused on buildings’ façade, as they are responsible for 10% to 20% of the total embodied carbon emissions of the building and they are external elements easy to be accessed, maintained and assembled. The different actors involved in the façade value chain have been identified, through action research methodology. Besides, the collaboration among the actors involved, on the one side, in the circular product development (i.e. exploration phase) and, on the other side, in the circular business model design (i.e. exploitation phase) have been detected. We posit that (i) collaboration is key in order not to have mismatches along the whole value chain and be able to exploit the potentialities of circular economy, (ii) different actors are involved in exploration and/or exploitation phase performing the same or different roles, depending on their specific skills and resources.