The international solar thermal market has progressed strongly over the last years. Especially in China, the USA and Europe, the manufacturing and commissioning of installations has grown rapidly. The major share of worldwide installed solar-thermal collectors consists of vacuum tube and glazed flat plate collectors. Both types are currently produced by time-consuming and cost-intensive manufacturing processes requiring different material classes. Novel polymeric materials and their implementation in solar-thermal systems are recognized as key technologies for the attainment of mid- and long-term development targets of the solar-thermal industry. Additional markets are identified for solar collectors which can be integrated in the building envelope properly. The presented proposal addresses the necessary R&D work to select and develop suitable polymer grades and collector designs to enter these markets with cost efficient and durable solutions to increase the share of renewable energies for domestic hot water and heating applications significantly on a world-wide scale. The main objectives are:• Innovative thermo-siphon solar-thermal systems designed for polymer components and systems for polymeric flat-plate collector, which are designed for high efficiency and durability and appropriate for the integration into the building envelope.• New polymer material grades with promising cost performance ratio and proven long-term durability for absorbers, which can be processed either by injection moulding or extrusion.• Prototypes, which are tested and qualified with respect to durability, performance and potential for building integration.The special requirements and conditions of solar thermal systems for polymer based collectors will be taken into account on all levels of the project. Interaction with the ongoing Task 39 of the IEA Solar Heating and Cooling Programme facilitates synergies and a broader dissemination and exploitation of the results.