In order to underline the symbolism of “V”, particular emphasis was given to transparency. This goal was achieved, using over 1,700 sophisticated, production-optimised heroal elements from the heroal S 77 SL lifting-sliding system and the heroal W 72 window system. Since numerous custom-made units were required, due to both form and dimensions, and stringent demands for quality, design and technical detail had to be adhered to, the Sipral a.s. metalworking company made a conscious choice for heroal as a system supplier: “Not every manufacturer in the segment has the capacity to reliably realise such complicated projects, or to satisfy our stringent requirements. For this reason, we made a deliberate choice for the innovative family-owned heroal company, which provides outstanding “made in Germany” quality,” says Leopold Bares, Chairman at the Czech company Sipral a. s. According to him, heroal is the sole manufacturer in the sector to have its own, in-house, state-of-the-art bending and folding service. Additionally, heroal’s in-house, highly weather resistant surface coating ensures long-term, top-quality colour stability, gloss retention and durability against weathering. Particular attention was paid to technical aspects - given the unusual design and the building’s height, construction had to achieve specified wind load resistance rating class C3 and water tightness 8A. Windows and lifting-sliding elements were also required to achieve a noise insulation rating of up to 39 dB, thermal insulation of 1.5 W/m²K, and class 4 air permeability. This posed no problem for heroal – the heroal W 72 and heroal S 77 SL systems exceed these requirements.