This book examines green transition and circular economy in the fields of building design and Real Estate management. By outlining windows for seizing the opportunity to integrate circular approaches in current building practices, the book provides information tools to support building stakeholders (e.g. building designer and managers, manufacturers, Real Estate owners, maintenance operators, facility managers, etc.) in: (i) understanding circular re-strategies (e.g. reuse, remanufacturing, repurposing, etc.), the related requirements and the pre-conditions for their implementation within building design and management practices; (ii) reviewing design approaches at the product and building scale, also highlighting new circularity-related contents for the Briefing Documents; (iii) developing circular organizational and contract models for the procurement of Facility Management services, also integrating new circularity-related contents in Invitations to Tenders (ITTs); and (iv) assessing the quality and the effectiveness of circular practices, also highlighting circularity performance metrics and indicators in the context of corporate sustainability reporting.