As one of the oldest Portland cement factories in both Germany and Europe, Bonn’s 1858 rawmill is a historic listed building. Together with the neighbouring Director’s Villa and water tower, the “Rohmühle” has become a symbol of the new Bonner Bogen development. The complex is now home primarily to office space, with a restaurant on the ground floor. And what Rhineside restaurant would be complete without a sheltered outdoor dining area?
Combining the interior with the great outdoors
Since the Rohmühle and the other buildings that make up Bonn’s old cement factory are listed, the architects needed to come up with a design solution that would make the Rohmühle stand out as an independent new element separate from its roots, while still ensuring it fitted in as part of a functional whole with its neighbours. The old patio was the obvious place for an extension, due to its attractive location on the bank of the Rhine. The patio was extended to stretch closer to the river bank, and given a complete overhaul with an exposed concrete supporting wall and fishbone brick paving. The paving carries over into the wintergarden, making the area seem more like a distinct outdoor area, rather than an extension of the indoor gastronomy space. This aesthetic is reflected further by the fact that the wintergarden can be cut off entirely from the building using a bi-folding door, and opened out onto the outdoor area instead.
With a slender sight line of 99 mm in the panel butt joint, the Highline and Ecoline bi-folding door systems used in the wintergarden maximise the glass area in play, providing almost complete transparency. At the heart of the glass front is a multi-functional break profile, which combines a range of technical details to enable the use of slender profiles with large, heavy elements without compromising on thermal insulation. With its smooth-running, low-wear, stainless-steel carriage technology and accessible floor track, the Solarlux bi-folding door is the perfect choice for the Rohmühle restaurant. Based on an accordion principle, the glass elements can be folded open along the a width of around 12 metres and stowed away as a compact unit at the side, thus providing a seamless transition between the indoor area and the wintergarden. What’s more, the wintergarden’s facades open up on all three sides, allowing the patio in front of it to be expanded as needed. But even when they are closed, the area offers guests spectacular views of the Rhine.
