In the present paper an overview is given on design options and sizes of the main components of worldwide installed solar heating and cooling (SHC) systems. Within an IEA project over 300 systems could be documented, including over 130 large scale custom made installations. The implemented hydraulic schemes have been analyzed following 6 main criteria. References and examples are given where single solutions have been implemented. The analysis starts with the solar loop. The focus is on: possible connections of the collectors field with the heat store – if available – and possible layouts to supply heat to the thermally driven chiller (TDC) or to the heating distribution system. The layout by means cooling is supplied to the users is also analyzed, including possible cold stores. Interconnection between stores – if more than one is included – and integration of back-up systems, on both the hot and cooling sides, are discussed as well. Concerning the sizing, statistical analysis have been carried out to identify common practices for basic ratios, e.g. collectors ‘area per nominal TDC power, storage capacity per unit of collectors area and so on. The research shows that there are many different design options implemented worldwide. Only in recent years a standardization process of design and sizing has started, mainly driven by companies specialized on the installation of these systems relaying on in house proven solutions.