The International Building Exhibition 1987 (IBA) was an architectural exhibition and an urban planning concept of the Berlin Senate to regain the West Berlin city center as a residential location. The idea came from the Berlin senate building director Hans-Christian Muller. The early urban development of the post-war period in Germany rejected the historical building structures. Whole neighborhoods were demolished and replaced by completely new structures. Other existing buildings were deliberately abandoned to decay, soon to be replaced by office towers. The new IBA contrasted with the Interbau of 1957. For the first time in the history of the building exhibition, the central concern was the renewal of old buildings and the insertion of new buildings in the city.
IBA-Altbau epitomised new approaches to cautious urban renewal. The growing resistance of many citizens against the destructive refurbishment of the 1970s led to a fundamental reorientation in urban renewal. The programme was divided into 'IBA Neubau' (new buildings), under Josef Paul Kleihues, and 'IBA Altbau' (mainly the repair and alteration of existing blocks), under Hardt-Waltherr Hamer. Neubau was across Tegel, Prager Platz, southern Tiergarten and southern Friedrichstadt, Altbau in Kreuzberg only. Altbau includes many new buildings, such as Alvaro Siza's Bonjour Tristesse but the tag was given to signify that such buildings were integrated into existing street blocks.
The 12 principles were first presented publicly in 1982 by the head of IBA-Altbau, Hardt-Waltherr Hamer, and passed soon afterwards by the district of Kreuzberg and Berlin's City Parliament. The aim of the 12 principles was socially-compatible preservation and resident-centric modernization of neglected inner city quarters and existing buildings. The previously common practice of demolishing existing buildings and building new buildings on the outskirts of the city was abandoned. The residents were also to be involved in planning and implementing the building projects. This secured living space, while also preserving public and social infrastructures, and developing them with projects that integrated employment, education and recreation. That was intended to create liveable urban districts.
The 12 principles can be summarised as follows:
- The renewal must be planned and implemented (preserving the substance) with the current residents and business owners.
- Planners should reach agreement with the residents and business owners on the objectives of the renewal measures, and produce technical and social plans.
- The unique character of Kreuzberg must be preserved, while trust and optimism must be restored in the at-risk city districts. Damage to buildings, which threatens their structural integrity, must be rectified immediately.
- Cautious changes to ground plans must also make new forms of living possible.
- Houses are to be refurbished step by step and supplemented gradually.
- The building situation must be improved by few demolitions, greening inner blocks and with facade design.
- Public institutions as well as roads, squares and green spaces must be renewed as required, and supplemented.
- The participatory rights and material rights of those affected by social planning must be coordinated.
- Decisions on urban renewal must be made openly and discussed locally where possible. Local representation must be enhanced.
- Urban renewal that generates trust calls for reliable financial commitments. Funds must be available rapidly and invested appropriately.
- New forms of organisation must be developed. Trustee-based redevelopment bodies (services) and construction measures must be separated.
- Urban renewal in accordance with this concept must be guaranteed to continue beyond the end of the IBA.
A similar set of regulations, though not quite as clearly formulated, was also developed for IBA Neubau for critical reconstruction. This included preservation and development of the existing urban ground plan as the memory of the city. The design vocabulary of the new architecture must be derived from an analysis of the existing buildings and reference existing building structures in ground plan and elevation. Independent application of these rules facilitates diverse design variations for the respective location.
In the context of a re-evaluation of life and economic patterns in Western Europe and the US, the focus was on the cities, their spaces, buildings and patterns of use, raising questions: Was property speculation about to turn the city into a "profitopolis"? Did pragmatic economic thinking lead the modern age into the "construction industry functionalism"? And who owned the city - and who had to decide on the design and use of their rooms and buildings? "The questions that affect urban renewal are in principle the same everywhere as in Berlin," the initiators of the IBA quote, "only in some respects the problems here are particularly massive and particularly acute,
Divided into the development of old and new housing developments - the "IBA-Alt" and "IBA-Neu" - six demonstration areas were selected, to which social, urban planning and architectural issues were identified in advance and action goals were defined. In southern Friedrichstadt, in the southern Tiergarten district, at the Prager Platz, in Tegel, in the Luisenstadt and Kreuzberg SO 36, a large number of projects developed on the basis of scale between the construction of new urban quarters and the subtle intervention in the existing buildings Action level between star architect and self-help group varied.
"Urban Repair" and "Critical Reconstruction", "Laboratory" and "Workshop", "Process" and "Cautiousness" were methods and key concepts of the IBA, which accompanied and survived the paradigm shift in Berlin planning culture. Until the anniversary year 2012, the urban spaces and buildings of the IBA are being researched and documented in a survey. Almost 25 years after the IBA, a first comparison can be drawn between what was wanted and what has become of the IBA. What has become of the thoughts and buildings of the IBA, what is still there, what has changed and how should we deal with the existing in the future? Closely related to this is the question of the historical and aesthetic value of this phase of urban planning in Berlin and the resulting buildings and structures.
Here are some of the most prominent IBA-Neubau projects: Checkpoint Charlie Apartments, Checkpoint Charlie Museum, IBA Block 2- especially Hadid IBA Housing Block 2, IBA Block 6, IBA Block 9, Hejduk Tower, IBA House for Two Brothers and Gate House, Berlin Social Science Center, Botta House - Lutzowplatz , Eco-Houses, Raimund Abraham House and IBA Lutzowplatz Apartments, the only IBA 1987 building that no longer exists - it was demolished in 2013.
Among most famous of IBA projects are IBA Block 70 and Bonjour Tristesse.