To reduce the heat loss in heritage buildings, this graduation research aims to explore what alternative solutions arise when thin glass is used to design an insulating glass panel that replaces the single glazing? To do so, six different designs are proposed. The first two are an IGU with thin glass and laminated thin glass. The third design is made with a hollow twin-wall sheet of PC and laminated to thin glass. The fourth and fifth proposal are laser cut PMMA connected to thin glass. While design four uses a honeycomb pattern, the fifth proposal experiments with a more freely design of cavities. The last proposal uses glass balls in the cavity of the IGU.

Based on the computer analysis, design 5 and 6 fail on the thermal properties and design 1 and two cannot handle the wind load. For design 1, 2, 3 and 4 prototypes are made but design 4 did not succeed during this research. The others were then tested on the U-value and the maximum force before breakage. This concluded that design 3 performed thermally as expected but design 1 and 2 performed worse, due to a flaw in the computer modelling. Converting the force to the maximum distributed load showed that all designs could handle the wind load. The materials were also tested on ageing due to UV rays. Only the polycarbonate changed significantly over ten years, but with an extra UV-coating, this is avoidable.

The aesthetic of the design 3 and 4 and the opinion of the public are tested with a survey. It can be said that the division between design 3 and 4 was fifty-fifty. If the other design had a better U-value, they did not switch. Depending on the function of the space behind it, people chose design 3 for more private spaces and design 4 for more public spaces. To show the final appearance and precision of the designs, a rendering and details are given. After this, a table is made to compare the designs based on stars which concludes that design 2 is the best alternative solution to replace single glazing in heritage buildings.