Resilient Storage is a project that focuses on designing a protocol for Belgian museums to implement short term energy-savings strategies, decrease CO2 emissions and improve preservation conditions. Cultural institutions’ mandate to optimally preserve their collections often encourages them to invest in Heating, Ventilation and Air-Conditioning (HVAC) systems to strictly control the indoor climate in their collection storage. These HVAC systems induce high operating costs and energy use. Today’s context calls for a combined strategy, one that reduces an institution’s environmental impact and at the same time sustains or even improves preservation conditions. Resilient Storage aims at helping museums to define an optimal indoor climate, taking into account the collections requirements, the capacity of the building envelope and climate control systems, and the human needs. This requires an interdisciplinary approach between preventive conservation specialists, engineers, collections and facility managers, with support from upper management. The Resilient Storage project focuses on how the building’s inherent hygrothermal properties can be used in order to reduce the energy consumption for indoor climate control, while maintaining an adequate climate for the preservation of the collection. The protocols starts with a focus on documentation. The indoor climate and energy consumption of the climate control system are monitored for several months in two cultural heritage institutions to obtain insight into the buildings’ current behavior. This allows identifying possible pre-existing issues, such as incorrect relative humidity, and other obstacles, such as a faulty air tightness or a detrimental ventilation rate. Based on these findings, a number of tests and interventions are defined for the case-study museums. This article will focus on several tests that are conducted in order to evaluate and improve the indoor climate at two Belgian museums: the Belgian Comic Strip Center (Brussels, Belgium) and the FeliXart Museum (Drogenbos, Belgium). Both museums are chosen because they have different building envelopes, (HVAC) systems and collections. The FelixArt Museum houses a modern art collection. The building dates from 1996 and is equipped with a HVAC system for both exhibition rooms and storage spaces. The Belgian Comic Strip Center on the contrary is housed in a 1905 Art Nouveau building. They focus on temporary exhibitions and have therefore a smaller storage area that houses predominantly comic books. They have limited climate control consisting of one small air conditioning unit per depot. In the FeliXart museum, a first test investigates the impact of reducing the ventilation rate in the storage area. A second and third test aims at widening the acceptable bounds of both temperature and relative humidity. A fourth test investigates the impact of reducing the amount of fresh air in the ventilation air mix. At the Comic Strip Center, the first test indicated that shutting down the two air Conditioning units for several days results in a rapid, significant increase in temperature and a slow but nonetheless significant decrease in relative humidity. In subsequent tests, the plan is to reduce climate variations in the surrounding exhibition area, as this significantly impacts the storage area.