The transition from linear to circular economy is still far from being completed, particularly in the building industry. Indeed, its specific characteristics – such as the fragmentation of its business ecosystem – hinder the implementation of circular economy practices, and, particularly, circular product design and servitization practices. This paper analyses the collaborations among the companies involved in the design and servitization of one of the major elements of a building, the building façade, and it leverages on an action research methodology based on the “Envelope for Service” research project. The role of companies involved in the design and servitization of the circular building façade has been investigated. A novel research framework has been developed to match the circular practices implemented by the ecosystem of involved companies along the useful life phases of the building façade. The research framework highlights the paramount importance of collaborations within the business ecosystem of the building façade and shows how the interactions among companies take place and facilitate circular product design and servitization. We argue and provide evidence that the engagement of the whole business ecosystem is needed in fragmented industries, like the building industry, to implement circular product design and servitization practices. Finally, a hint of the relevance of digital technologies in enabling the implementation of circular practices in such industry is provided.