Sustainability and energy efficiency were what the design of the Z3 in Stuttgart, Germany, focused on right from the start. Since completing in 2012, Züblin's headquarters has served as a test subject for buildingintegrated photovoltaics (BiPVs). To this end, the southern facade was equipped with photovoltaic (PV) modules that were only attached using a structural, load-dissipating adhesive bond, without additional mechanical fastening. Züblin, one of Germany's biggest construction companies, closely cooperated with Kömmerling Chemische Fabrik, an adhesive and sealant manufacturer based in Pirmasens, for this project.
From 2020, all new buildings in EU member states must generate as much energy as they consume. PV systems are perfectly suited to generating renewable energy near buildings; they have low emissions, minimal noise levels and are low maintenance, and can take on a building's functions when integrated, as can the facade. However, BiPVs' downsides are visual appearance and the standardisation of elements complicating the provision of individual facade designs. The opposite is now being demonstrated by Züblin's fivestorey Z3 office, which was designed by MHM architects. In 2014, the nearly zero-energy building was awarded a DGNB gold certificate.
A glued PV facade with screenprinted pattern - designed by UNStudio - was finally added to the south side of the building last year, as part of the EU-funded research project Construct-PV. Thanks to the load-dissipating adhesive from Kömmerling, the elements were harmoniously integrated in the architecture without needing additional mechanical securing. The building is characterised by wooden pilaster strips and contrasting, dark-looking facade sections, where windows alternate with graphite-grey glass balustrades. The tempered-glass balustrades, which were glued down before in a load-dissipating manner in accordance with structural glazing principles, were replaced by glass-glass PV modules. Kömmerling not only supplied the structural-glazing silicone for the modules' glued attachments, but also assisted with the approval procedure. Without mechanics, the attachments needed to be approved on a case-by-case basis.
Kömmerling has been part of the US adhesives group H.B. Fuller since October 2017. The acquisition of Kömmerling's parent company, Royal Adhesives & Sealants, drew attention to the German locations of Pirmasens and Langelsheim. Together, the companies grew into the world's largest provider of adhesives and sealants for insulating glass applications. The acquisition raised the annual sales of H.B. Fuller to $2.8 billion. In combination with Royal and Kömmerling, H.B. Fuller has deepened its expertise in highquality adhesive and sealant applications that are employed in a number of industries, such as electronics, hygiene, medicine, transport, construction and renewable energies.