The specialist lecture covers the topic of green building in general, as well as green building in relation to clean room technology. The focus of the lecture is on the presentation of possible cycle models for interior fit-out products in clean rooms (e.g. ceilings, walls, floors) with examples for the preservation, reuse, processing and recycling of individual components. Furthermore, various circular models, such as purchasing with return or renting products, are explained. Another focus is on the explanation and future importance of EPDs (environmental product declarations) - also and especially for cleanroom technology. Finally, recyclable products are presented using the examples of floors, ceilings and walls.