The internationally-acclaimed extension to the German National Library in Leipzig features a series of bespoke façade solutions from Wicona.
Designed by Gabriele Glöckler and realised by the Glöckler team and ZSP Architekten, this stunning building has a glistening and sleek envelope that makes a strong visual impression. The scheme provides more space to archive Germany’s national cultural heritage, which increases by around 600,000 new media every year, and houses almost 140km of shelving, the German Book and Media Museum, and the German national music archive, which has been relocated from Berlin to Leipzig.
This is the library’s fourth extension and an important aim of the project was to unify the three earlier and very different architectural styles – from the historic 1912 neo-classical façade to the 1970s windowless tower complex.
Several bespoke façade solutions were developed for the project by Wicona in conjunction with the fabricator, MBM.
The glass for the vision areas of the Wicona curtain walling is coloured in 15 graduated shades of red and grey, which allude to Bach’s Fourth Goldberg Variation and Leipzig’s long musical heritage. These elements also deliver a light-reflecting factor of more than 50 per cent using a screen printed dot pattern and give the building a changing aspect in different light and weather conditions.
The book repository is designed to resemble a book on its side. Here, Wicona’s WICTEC 50 unitised curtain walling system carries aluminium composite cladding, which was installed in a triangular pattern of silver panels. Bespoke triangular-shaped windows based on Wicona’s WICLINE casement system, were also inserted into the cladding to reflect the design of the aluminium panels.
The façade has 36cm insulation for exceptional energy efficiency and almost achieves Passivhaus standards. This helps to maintain the carefully controlled internal environment required for the storage of precious books. Air locks are used for entry and exit into the repository, and temperature and humidity levels inside the air conditioned rooms can only fluctuate between very narrow tolerances, from 14 to 16°C.
On the ground floor, the 3.4m high unitised panels are fixed to a supporting steel structure which contains heating elements to warm the aluminium mullions and transoms. Around 100m of cantilevered aluminium shelving is fixed to the façade, which also provides shade from the sun.
The aluminium cladding features on the museum bridge and the connecting core to the existing library building. Here automatic parallel outward opening vents were integrated into the curtain walling, for natural ventilation where required and are concealed when closed for a seamless appearance. Solar control is provided by integral blinds within the glazed units.
The museum bridge has a mixed building envelope, comprising ‘stick’ curtain wall glazing, a rear-ventilated façade, and a unitised façade using an adaptation of the WICTEC-EL system.
The curtain walling on the project helps to realise the scheme’s transparent architectural design theme, which is in keeping with the organisation’s aim to promote the treasures and services of the National Library – and help to turn the extension into an eye-catching gem.
The Wicona façades, which were all specially-developed solutions, were individually tested at the Wicona Test Centre at Bellenberg, Germany. Tests were carried out for air permeability, static and dynamic water tightness against driving rain, and resistance to high wind loads.
The German National Library complex now presents a series of stylish buildings for a historically valuable cultural treasure. The new extension provides 7,000sqm of air conditioned storage space and 4,000sqm of exhibition space. The facilities are designed to accommodate all German publications that will be archived over the next 20 years under modern conservation conditions.