This document specifies general requirements for showcases for safe and secure display of cultural heritage objects complying with the requirements for preventive conservation. This document is only focused on so called passive showcases with unpowered climate conditioning systems, displaying the objects in ambient air. The role of the showcase in the preventive conservation is established by a risk assessment taking into account several risk factors mentioned in this document. As the design of the showcase has an influence on its properties, some general consideration about the showcase design are given. The procurement of showcase(s) and the development of the design of the showcase(s) involve all stakeholders of the project; a structured project plan is proposed.