In Leipzig, the German National Library's latest extension has opened after an almost four-year construction period. Founded in 1912, this is the library's fourth extension. It was designed by Gabriele Glöckler, winner of a European architecture competition, and planned and executed by the team Glöckler and ZSP Architekten architecture office. Urban development and design The fourth extension not only adds a new autonomous architectural element to the Deutscher Platz but also provides a harmonious link between the main building and the Book Tower of the German National Library. The first two annexes stretched out behind the the façade of the German Library, built in 1916 by Oskar Pusch. In the 1970s, however, the GDR, set a cool, windowless complex consisting of five high towers slightly apart from the the historic building. The newly created extension closes this gap and links the neo-classical rectangular building, rendered less severe by Viennese art-nouveau nuances, with the book towers to form a whole entity. The new extension means the three very different building styles now interact with one another. Building concept According to the architect, “The concept “envelope– cover – contents” translates the function of the building into architecture. “Function creates Form” The extension of the German National Library in Leipzig is a bold curve and focuses on the function of the building. The German Book and Writing Museum is located on the slightly recessed ground floor. It opens up to the view of passers by; the positioning of the new entrance creates a visual link with the original building's main entrance. “The contents are protected by a compact cover around the repository area. A light envelope forms the exterior shell and connects the separate areas”, explains the architect. “Allusion is made to both Leipzig's musical tradition and the German Music Archives by using façade elements in graduated tones of red to interpret Bach's Goldberg Variation number four. Realisation of the Outer envelope The building's exterior wall construction (cover) enfolds the supporting skeleton of floors and piers (contents). A glistening silver envelope, acting as all weather membrane, encompasses the various areas and defines the outer shape of the building, creating a climate buffer around the fully air-conditioned book repositories. The recumbent tome's sleek envelope, made of ALUCOBOND® aluminium composite panels, fits snugly around the volume offering protection to the contents as well as the cover. The envelope's triangular pattern of joints suggests a tangible, abstract cloth-like surface. This surface effect continues in the cover and can be found once again in the interior: in the staircase as well as on the ceilings or in the reading room. The demand for consistency stems from the envelope's design concept, and material qualities such as lightness, formability and rigidity are essential for such a consistent application. The protective role which the envelope plays is not merely a visual impression but a real and durable function. There is a fluent transition to the towers in terms of material. Neutral white ALUCOBOND® has been selected to face the book tower and emphasise its cubic visual aspect. Energy concept The envelope and cover are integral parts of the energy concept. Insulation and weatherproofing material was attached to a wood construction. The mounted metal sub-structure supports the ALUCOBOND® tray panels bent on two sides. The rear ventilation of the well insulated double-shell building envelope can be regulated by flaps. So, the heat from the sun's rays can be expelled in the summer and in winter, when the flaps are closed, the stationary air serves as insulation against the cold. The exacting demands made on the thermal engineering, a constant humidity of 50% at 18 degrees Celsius in the book repository, were linked with the use of geothermal energy by an innovative concept. Geothermal energy was used to supply a large part of the building with heating and cooling water. There are 48 borehole heat exchangers sunk into boreholes measuring, all in all, 6 000 metres in length and124 metres in depth on the Deutscher Platz. This holistic energy concept creates about a 50% reduction in energy costs in comparison with conventional methods. Background: German National Library The German National Library, as largest German library, collects all German and German language works as will as foreign publications pertaining to Germany. It was founded in 1912 in Leipzig and is currently also located in Frankfurt am Main and Leipzig. Approximately 6000 000 actual media units (books, magazines, CDs, CD ROMs, DVDs) are added to its collection every year. At present, it has about 26 million works which are accessed annually by more than 226 000 reading room users. The German Music Archive, the German Book and Writing Museum and the German Exile Archive (1933-1945) also form part of the National library. A total area of 14 000 square metres is now home to the German Book and Writing museum as well as the German Music Archives which were previously located in Berlin. Building history of the German National Library in Leipzig Main building 1914-1916 First extension 1934-1936 Second extension 1959-1963 Third extension (book tower) 1976-1982 Fourth extension 2007-2011 NEW: The extension is to be presented at the Architecture Biennial in Sao Paolo 2011 The Federal Chamber of Architects (BAK), in conjunction with the Federal Chamber of Engineers (BingK), has compiled the German entry for the Sao Paulo Architecture Biennale 2011, following a commission by The Federal Ministry of Transport, Building and Urban Development. 20 projects were selected as winners from the 120 submitted. The theme of this year's contribution is “Building culture made in Germany”. Sigurd Trommer, BAK President, commented on what is required of the projects, “ In Sao Paulo, we want to present not only the high quality of our building culture and urban development but also the quality of engineering associated with German planning services. Alongside international relevance, it is about providing examples of sustainable building and solutions to specific national and climatic factors”. The IX. Sao Paulo International Architecture Biennial takes place from 1st November to 4th December 2011 PROJECT DATA: Building name: 4th Extension of the Germany National Library Leipzig Location: Deutscher Platz 1, Leipzig Commissioning body: Federal Ministry of Transport, Building and Urban Development, Chemnitz Regional Tax Office/ Free State of Saxony Federal Ministry of Finance since 1.1.2011: Public Enterprise Saxon Property and Construction Management Planning: Design: Gabriele Glöckler Planning and execution: work group Gabriele Glöckler/ ZSP Architekten Construction period: 2007 – 2011 Material: ALUCOBOND ® A2 Quantity: 15 085 m² Application: Renovation of the book towers: panels suspended on bolts: ALUCOBOND ® A2 white 16 New building in book spine form, SZ 20 triangular shaped panels in: ALUCOBOND ® A2 brilliant metallic Fabricator: Prefabrication: Aluform, Bad Rappenau Mounting: Henke AG, Zwickauer Straße 39, 01187 Dresden Further Information Excavation: 12m deep, 115m long, 30m wide (=3 450m²) Excavated material: 42 000 m³ Foundation on 1.9 m thick floor slab Concrete used: 14 000 m³ Steel used: 3 500 t Roof boarding: 4 700 m² Reinforced concrete beams: 1 500 m Timbering: 3 000 m² Underpinning of the existing building using back-anchored high pressure injection ( 2 200 m³ of concrete was pumped under the existing foundations to act as stabiliser) 1 300 m rear anchorage in horizontal layers, 3 800m (250 units) tie back anchors Geothermal energy use via 48 borehole
