Old stock exchange, Zürich


As part of a comprehensive renovation of the old stock exchange in Zurich in Bleicherweg 5, the existing roof with skylights was replaced with translucent aerogel elements in 2012. The replacement, which was executed by the company WEMA, the Okagel elements of the company Okalux were used. Due to the high wind loads on the roof near the lake, no standard glazing with external shading could be used. The translucent aerogel elements have a very low total energy transmission, a relatively high light transmittance as well as good thermal properties. Thus, no external shading is necessary while at the same time good light scattering in the interior and good thermal insulation is achieved. The used okagel elements have a g-value of 0.12, a visible light transmittance of 0.24, and an Ug-value of 0.6 W/(m²·K). Usually, such a u-value is only achieved with a much heavier 3-fold glazing. The elements are realized with a laminated safety glass inside and outside, 2 x 6 mm each. Approx. 680 m² of roof areaa was equipped accordingly.