A building sculpture made of lightweight concrete

Berlin: Residential and commercial building

Fig. 1 The lightweight concrete designed for the construction of the façade meets all requirements in terms of strengths, weight and manufacturability.

Fig. 2 The six-story building with the black façade made of Liapor lightweight concrete appears as if cut out of a
single block.

 The six-story residential and commercial building that has recently been completed in Rosa-Luxemburg-Platz in Berlin appears as if cut out of a heavy block. With its volumes stacked above and nested into each other the monolithic building in a black fair-faced concrete look leaves a cubistic impression and allows at the same time also a certain lightness to appear due to the large cantilever components. The building having an overall size of about 2,060 square meters was designed by the architect Roger Bundschuh in cooperation with the artist Cosima von Bonin.

One of the highlights of the new building is the black façade appearing in a fair-faced concrete free of joints. However, owing to the ambitious architecture with cantilevers of more than twelve meters, it was at the same time necessary to find an especially lightweight and load-bearing concrete which in addition had to meet perfectly the requirements of an as dark and smooth surface as possible without any lime efflorescence and shrinkage holes or glossy spots. For reasons relating to building physics and statics a double-shell external wall structure with core insulation was chosen with an...