Project type: Urban Planning, Adaptive Reuse
Location: Berlin, Germany
The south-east corner is the busiest entrance to the parkland of the former Tempelhof airfield due primarily to its good transport connections. The design for a new central library for the city and state of Berlin at this point, and its articulation as a high-rise structure, reorganises the entrance situation next to the axis of the former runway and establishes the building as a landmark and gateway to Berlin for visitors from near and far.
The design proposes extending the typical Berlin-style rectangular block-courtyard structure at the edges of the site, while decreasing its height successively storey for storey from west to east ending with a four-storey building plus stepped-back roof storey along the edge to the park to produce a defined border of a more appropriate scale. The same principle is used to the south of the library site.
Two urban figures delineate this extension of the city. Firstly, we extend the north-south arc of the old airport railway line causing the street to widen into a public square, and then we slice through it with the axes of the two runways, resulting in a linear space between the two former runways. This sense of movement is nevertheless of secondary importance, as it opens onto a large urban space that is defined by the large volume of the library and surrounding buildings.
The design positions the Zentrale Landesbibliothek (ZLB) as a tall rectangular volume within this space, creating two clearly defined urban spaces between the library and block edge. Its rectangular form and position within the urban space continues the overall pattern so that there is no abrupt shift in the urban experience as one emerges from the surrounding urban realm. Nevertheless, its dominant height, change in scale to twice the block width and formal articulation sets it apart from the surrounding urban blocks, giving it an unmistakable presence and identity that is visible from afar.
As an urban hybrid, this ‘mega-block’ succeeds in connecting the quarters to the south and north through its kinship with the rational order of the urban blocks. The parallel alignment of the faces of the urban blocks results in a play of self-similar spaces and volumes that help it be experienced at street level as part of a continuous urban realm. At the same time, it stands out as a solitary character, due to its large size on the one hand and its architectonic articulation on the other.
The position of the ‘mega-block’ in terms of its proportions and east-west orientation sets up a discourse with the succession of spaces around it. Shifted close to the runway edge, the library stands in line with the row of poplars that flank the main entrance corridor to the parkland of Tempelhof’s airfield. To the west, on the large urban space, the axis of the runway is continued in the form of water surfaces. This helps give the urban space a human scale and the noise of the water muffles traffic noise from the urban freeway and railway line. This urban space has the character of the city, its stone surfaces optimised for pedestrian flows coming from Tempelhofer Damm, the underground car parks and railway station exits. Green islands and street furnishings help break down the size of the large urban space into smaller-scale ‘urban microclimates‘.
In the north east corner, a compact but tall block steps forward from the urban block structure, functioning as a kind of gatehouse to the library square at Tempelhofer Damm. At the same time, its position narrows the square at the hinge-point where the large urban space meets the widened street space to the north and linear tree-lined space adjoining the residential quarter north of the library. These different interpretations of piazza or piazetta serve to avoid the problem of left-over space around a freestanding solitary building and help to zone the urban realm according to prominence and degree of use, so that each of these urban spaces can acquire its own identity.
The dominant architectural gesture of the new library reinforces the intended qualities of the urban space. Its grand entrance and approach opens onto the square welcoming the estimated 10,000 visitors per day, many of whom will arrive via public transport. The longitudinal placement, the ascending series of stairs running from east to west, connects the city in the west to the parkland areas in the east both functionally and symbolically.
The building’s design embraces a new spirit of civic openness. In modern Berlin, the library of the future is one of the few large indoor urban spaces in the city that people can use without having to purchase something. In the context of today’s urban and democratic rituals it therefore has the potential to become a new kind of civic meeting place in the city that goes beyond its central purpose as a place of reading and repository of knowledge. As such, the library comprises not just the reading rooms and study areas one would expect but also a large, public sculptural stair that is cut into the mass of the building so that it is at once part of the building and of the urban realm.
The architectural design compresses the extensive functional programme into a twelve-storey building the size of a football pitch. The main mass of the building is efficiently stacked in a rational block which is clad by a transparent façade system that ensure it receives natural light along its entire length. The building’s depth is nevertheless sufficient to ensure stable environmental conditions in the core zone of the book stacks despite the transparent facades.
The building’s transparency is the first and most obvious indicator of its public openness. A diagonal void running through the building serves on the one hand to zone and illuminate the respective storeys and rearward areas and on the other as a giant architectural gesture inviting all to enter this modern 21st century library.
The enclosed book stacks and supporting ancillary spaces of the library are located in the six lower storeys of the abstract rectangular volume. Out of this block of books, a void has been cut that allows one to see right through the building from the entrance at the urban square up to the sky. This void ascends in the form of a large sculptural public area that extends the urban realm up to the lobby zone on the seventh floor. Lifts, escalators and stairs criss-cross the void, traversing the space from the street to the upper levels. The street furniture from the urban square likewise springs nimbly onto the ‘hillside’ of the large stair looking back over Berlin, inviting people to occupy the sculpture with their own rituals.
The gesture of the grand stair slicing through the side of the building like a gash in an upturned mountain continues on inside in the form of an atrium in the lobby and public zones. On climbing the ‘book mountain’ to the roof, one is rewarded with a breathtaking view over the airfield of Tempelhof airport from on high. From this perspective, the flat expanse of the airfield can be seen in its entirety and appreciated as a space in the city.
The diagonal atrium divides the building into different zones and activities providing numerous opportunities for different kinds of personal and communal interaction. Th library of the future must provide a range of attractive places to meet and be. Access to knowledge in the 21st century is not confined to solitary study but also encompasses forms of collective discovery. As such, GRAFT’s design for the ZLB is a place of communal movement and experience. The grand stair is not just a walk-on sculptural landscape but also a reinterpretation of the atrium and reading rooms of old as a place for dreaming and imagining high above the city. This elevated public space extending sublimely to the horizon radiates beyond its immediate environment, inscribing itself into the memory of the city, its architecture serving as a landmark inviting all to come and partake of the knowledge of Berlin.
“I have always imagined that Paradise will be a kind of library” – Jorge Luis Borges, The Last Voyage of Ulysses
The compact, rational building figure and concentration of services ensures optimized internal operational procedures. The frame structure employed also affords maximum flexibility for future adaptations. The advantageous surface to volume ratio is only compromised where the sculptural stair cuts through the building but does not impact on the general efficiency of the building.
The structural framework has a large grid of columns, maximizing the use of prefabrication and efficiency. The floor slabs conduct the load via prefabricated elements to beams at 11-metre spacings, resulting in a cost-effective but also highly-flexible construction. Rigid utility, stair and lift cores serve to stiffen the building.
A common energy concept is proposed for the entire quarter around the library that can accommodate fluctuations in energy demand between the library and the residential and retail areas around it. Energy provision at the scale of the quarter is more efficient and obviates the need for extensive technical installations on the roof of the library. The energy concept comprises a combination of cost-effective heat pump (powered by photovoltaic panels) complemented by a gas-fired condensing boiler. Such systems are practically carbon neutral, cost-effective and already widely used in the neighbourhood. A geothermal heat pump can cover 70% of the annual heat demand given the corresponding outdoor temperatures. The pumps are powered by photovoltaic energy with surplus energy being returned to the power grid. With this system, the cost of energy provision is approximately 30% lower than that of district-heating systems.
The library combines a compact building mass with a highly-efficient façade and also maximises use of natural light and winter sun. Rainwater from the roof and outdoor areas is retained for reuse. The water surfaces on the urban square, together with the prevailing wind direction create a pleasant microclimate and can help reduce outdoor temperatures in summer. Planting on the grand stair also counteracts the negative effect of wind gusting and draughts.