Since the oil crises during the 1970s, there has been a growing awareness of thermal losses through windows in buildings. Nowadays, double-glazing is a common product for moderate maritime climate. In the Netherlands two permit requirements are calculations regarding nearly zero energy and environmental performance of a building. In order to reach nearly zero energy buildings, triple glazing and even quadruple glazing is considered as possibility. This has negative affects on the environmental performance of a building, because glass does need a lot of resources for production. A solution to that challenge could be the application of thin glass sandwiches, a structural sandwich with two ultra-thin faces (0.5mm) of glass. The structural sandwich is common in the aviation industry to stiffen and strengthen an element without adding significant weight. Downside is the increased conduction through the core material. Question is: to what extent can a thin glass sandwich panel, compared to regular insulated glass units, counterbalance its decreased thermal performance by reducing embodied energy during production? This research focusses on the material choice, quantity and distribution in the core of a sandwich panel in order to maximize thermal performance for a moderate maritime climate. In order to do so, materials from the CES library are evaluated. Detailed analytical calculations are used to determine the thermal performance regarding different patterns. FEA simulation software is used to determine the thermal performance regarding the cross-section of the actual thermal bridge between the two faces. From this research, the best solution is picked and evaluated on energy consumption, order to identify the effects on a building scale. General trends are identified and transformed into a design for a thin glass sandwich. Next to that, design guidelines are extracted for designers in order to design a thin glass sandwich without the need of calculating.