Contemporary building envelopes, such as insulated glass units, achieve high performance levels but often add a significant amount of embodied carbon. There is, therefore, an incentive to reduce the thickness of the glass panels. The minimum possible thickness is often governed not by strength or manufacturing limits, but rather by deflection (serviceability) limits. Despite objective criteria guiding serviceability limits, user perception of deformation remains unexplored, leading to conservative designs. This research introduces a bespoke electro-pneumatic system for deforming glass at different levels and measuring user perception. The results demonstrate the feasibility of measuring human responses to deformations in glazing and provide essential data for setting serviceability limit. The experiments and corresponding user feedback indicate that humans are mostly sensitive to reflections and that the current serviceability limit of L/50 may be relaxed, presenting opportunities for material efficiency, such as adopting thinner glass in façades.

“If it can be measured, it can be improved.”