Environmental issues such as global warming, waste occurrence and scarcity of raw materials are facing more and more attention worldwide. To face these problems, the Ellen MacArthur Foundation published the concept of circular economy in 2013, which asks for an economic system in which materials are kept as long as possible within the economic circle in order to prevent waste production and to reduce the need for virgin materials. Focusing on the construction industry as being one of the biggest energy consumers and waste producers, great opportunities for improvements towards sustainability can be found. To support the practical implementation of the theoretical concept of circular economy, this study aims for the development of a process model for the circular real estate development process following the standard of Business Process Modelling and Notation (BPMN). To reach this, first nine propositions have been formulated based on literature reviews regarding the concept of circular economy and the traditional real estate development process. Secondly, these propositions have been evaluated based on expert knowledge of 21 field experts by performing two rounds of Delphi method including personal interviews and an online-survey. Based on this analysis, it is found, that an early implementation of the concept of circularity in the initiative phase together with a clear definition of the ambition, the relevant circularity principles and necessary development partners are of high importance. Due to the need of specified knowledge, an early participation not only of the traditional team members, but also of the suppliers, producers and construction companies responsible for construction and maintenance need to be arranged in alliance with a clear documentation throughout the whole lifecycle of the building and its elements. Based on these findings, the process model has been developed in order to provide practical guidance for professional real estate developers for the development of circular real estate. This research provides the first approach of presenting a standardized and yet detailed process model useable for the practical implementation of the concept of circular economy. With this, this research is of high scientific and social relevance and forms a good starting point for further research.