The Müllerstrasse 16/20 building in the heart of Zurich is considered a pioneering project for the sustainable transformation of existing buildings. On behalf of Swiss Prime Site Immobilien AG, the building, which was constructed in 1980, was extensively refurbished for 220 million Swiss francs according to circular economy criteria and transformed into a modern office building.
For this project, the specialist for dynamically switchable liquid crystal glass eyrise B.V. supplied 3327 square metres of eyrise s350 solar control glass. With their neutral grey tint, the switchable glass not only blends in visually with the newly designed aluminium element facade.
See also: Glas Trösch offers switchable insulating glass
Thanks to their variable g-value, they also help to increase user comfort and reduce the CO2 emissions caused by the construction (grey energy) and operation of the building. This means that the eyrise glass can score points in several categories at once for the desired certification according to the Swiss Minergie standard and the SNBS sustainability label.
The client commissioned Allco AG (as general contractor) and the architectural firm Ilmer Thies Architekten AG, Zurich, with the planning and project management.
Cost-effective: Why was eyrise s350 chosen?
Commenting on the decision to use eyrise s350 solar control glass, co-owner Felix Thies explains: "Early on in the project, we toyed with the idea of working with switchable glass. The existing building was fitted with external venetian blinds, which are not only susceptible to wind loads, but were also costly to maintain. A life cycle analysis showed that the higher purchase price for the switchable liquid crystal glass compared to conventional glazing with external sun shading was amortised relatively quickly."
And Urs Baumann, Chief Investment Officer at Swiss Prime Site Immobilien AG, adds: "What particularly impressed us about eyrise s350 was the speed with which the degree of shading can be dynamically adjusted to changing weather conditions almost unnoticed by the building user. As the heat input and therefore the need for air conditioning is reduced in summer, this has a positive effect on energy consumption and CO2 emissions during operation. The elimination of conventional sun protection devices also resulted in an increase in rentable space for us as an investor."
Manufactured with green energy
Another advantage of the eyrise liquid crystal solar control glass is that it is produced exclusively in Europe using one hundred per cent renewable energy.
This not only enables rapid availability and short delivery routes, but also helps to reduce the proportion of grey energy, i.e. the CO2 emissions tied up in materials and buildings. Compared to standard glazing in combination with external venetian blinds, 750 tonnes of CO2eq could be saved.
Also interesting: Dynamic solar control and fire protection for the Alto Pont-Rouge in Geneva
"The social aspect was another important argument," Baumann continues. "The access to natural daylight and the unobstructed view, which is maintained even in the darkest shading level, contribute to the well-being of future users. This is why the eyrise glazing can score points in all three areas - society, economy and environment - for sustainable building certification in accordance with SNBS.
The appearance of the switchable glass is also perfect
The total of 1082 large-format eyrise s350 modules blend in perfectly with the colour of the unitised facade designed by Aepli Metallbau AG and made from recycled Circal aluminium from Wicona. The solar shading glass is controlled automatically via the building technology.
As certain areas of the facade are exposed to more sunlight than others, individual elements were combined into packages that can be switched independently of each other.
An analysis of the position of the sun over the course of the day and year carried out by eyrise provided valuable data for fine-tuning which parts require more and which require less sun shading. In addition, the shading can be adjusted manually by the user.
