Set against the redevelopment of the former Expo 2020 site into a sustainable, human-centric neighbourhood, the discussion opened not with glass but with human beings, how we feel, how we behave and what we need. Benjamin Beer of Werner Sobek Dubai, chairman of the Middle East region of the Society of Façade Engineering, put that case, joined by Arwa Alzaabi at the same firm; Jasmin Hodzic at Guardian Glass; Renato Cilento at Turner & Townsend; and Subraya Kalkura of John R Harris & Partners.

Light, glass, façades and buildings, seen through the people who live inside them rather than through their performance sheets.

The science made the case that light is never just illumination. Blue light at around 460 nanometres is used clinically, phototherapy that treats newborn jaundice by converting bilirubin into a form the body can clear, a condition that affects most babies in their first week. And the 2017 Nobel Prize in Physiology or Medicine was awarded for uncovering the molecular machinery of the circadian rhythm, the way our biology tracks the light–dark cycle to hold a 24-hour clock, mediated by melatonin. What reaches the eye sets the body’s internal time.

That is where the façade comes in, because a solar-control coated glass is a light filter: it changes the spectrum and the intensity of what gets through, which means the glass specified on a building is quietly shaping the circadian health and well-being of everyone behind it. The panel weighed this against the question of Sick Building Syndrome and whether filtered daylight still counts as “natural”, and where green-building goals and human-centric design might pull apart.

The discussion pushed façade thinking past thermal and daylight performance toward a human-centric standard, glass judged not only by its g-value but by what it does to the people living their days behind it.