Description

The Philosophicum is the most contentious of the buildings on Ferdinand Kramer’s university campus in Frankfurt’s Bockenheim district. The filmmaker Alexander Kluge, who began his training at the Frankfurt Institute for Social Research, considers the Kramer buildings to be some of the “most brilliant achievements” of post-war German architecture and praises their “delicate form”, while the more conservative writer Martin Mosebach, on the other hand, sees in them only “pure nihilism”.

Students who attended seminars there recall unbearable heat in summer and cold in winter – a factor of the construction method which minimised costs, materials and time (the steel skeleton frame was assembled in three weeks) as well as continuous neglect by the university’s building department. The nine-storey and just 11 m deep building began to decline after the humanities departments successively moved to the new Westend campus in 2001, and grew increasingly derelict after begin vacant for a few years. After debating its demolition, the university elected to sell it at the end of 2014 to the building developer Rudolf Muhr, who provides student accommodation in several cities across Germany, mostly in the form of “micro apartments” at much higher rents.

As “compensation for the additional cost of appropriate renovations to the historical substance”, the city and conservation authorities permitted Muhr to add an extension with a gross floor area of 3800 m². Stefan Forster, a declared opponent of Kramer’s urban design, developed a concept together with the conservation authorities that aimed to maintain as much of the original as possible despite the conversion. Kramer’s flexible construction proved conducive to the conversion: thanks to the external arrangement of the steel columns and lack of load-bearing walls and columns in the interior, it was possible to insert 174 micro-apartments into the grid of the existing building with a further 64 in the new building.

The conversion has turned the steel skeleton construction with curtain wall into a steel frame construction into which 18 cm thick highly insulated non-load-bearing lightweight metal panels have been inserted. To sustain possible high wind loads, the internal face of the façade was reinforced with C-profiles. The windows are mounted in thermally isolated aluminium profiles which over the entire length of the window are just 1 cm wider than the original profiles. The window arrangement and recessed ground floor level have been retained so that the overall impression of the east elevation is more or less identical save for a few minor details. The same applies to the gable ends and their brownish exposed concrete, which were insulated internally with mineral insulation boards.

The newly built five-storey block to the west is connected by a hall at ground level to the main building and by stairs on the upper floors. The wedge-shaped new building picks up the height of the surrounding blocks but is lower than the old building, allowing it to still be seen from the west. The floor plans of both buildings are identical but mirrored with the apartments arranged on the outward-facing elevations and the corridors towards the inner courtyard.

Like Kramer’s Philosophicum, the conversion and new extension are pioneering buildings – this time in terms of urban development. It marks the first attempt to preserve an important architectural monument of the campus and to retain its austere but also graceful aesthetics while also responding to the broader urban redevelopment. It represents a highly interesting but as of yet only experiment to integrate the “Island of Modernity” of Kramer’s university campus into the urban context. As such, its contribution will only be able to be fully judged once further parts of the still rather diffuse concept for the conversion of the university to a cultural campus have been completed.

Originally published in Bauwelt 10.2017, pp. 34-39, abridged and edited for Building Types online, translated by Julian Reisenberger

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