Description

On the site of the former Schierenberg primary school is a cross-shaped building from the 1950s designed by the then city architect of Hamburg, Paul Seitz, as a building prototype for schools. Seitz developed three school types: a pavilion type, a honeycomb type and a cross-shaped type that was built a total of 57 times in Hamburg up until 1962. As part of the reallocation of the building to the neighbouring secondary school, the architect Christine Reumschüssel has succeeded in elegantly converting the building, in the process incorporating rooms for the fifth and sixth grades.

Paul Seitz’s school buildings from the sixties, like the town planning of that time, were isolated buildings placed on open ground. Just like the high-rises that towered above the wide urban fabric of low-rise buildings, green spaces, streets and paths, setting accents in the suburban landscape, Seitz’s “Kreuzbauten” formed dominant urban landmarks in the context of the school gardens, playgrounds and pavilion buildings. Of particular note are the communicative central staircase providing access to four classrooms on each of the four levels, the quality of the slightly trapezoidal ground plans, which could accommodate a variety of teaching forms, the prominent structural brise soleil and the overall shape of the building. Few of these school buildings are listed as historical monuments, despite being worthy candidates.

Where buildings are not historically listed, the Energy Saving Ordinance applies in full and all too often the structural qualities of these buildings disappear beneath a thick wrapping of thermal insulation. Christine Reumschüssel, who previously helped several of Paul Seitz’s buildings gain a new lease of life and has detailed knowledge of their design, used her experience to undertake an intelligent conversion of this particular “Kreuzbau”.

The building had been vacant for a long time before the renovation and the conversion was not an easy undertaking, especially since the architect – with the support of the client – had set the goal to remain as true to the original building substance as possible. A key finding was that the reinforced concrete piers on the outer face only made direct contact with the building structure where they crossed the floor slabs and therefore did not need to be insulated. The only elements of the facade requiring thermal insulation were the walls and windows. These building elements, along with the gable walls, had to be redesigned. The green-white glass mosaic panels beneath the windows and the black clinker-brick gables are therefore not reconstructions but skilful replicas of the architecture of the sixties that fulfil today’s modern building standards.

A similar principle was applied to the classrooms. The basic room layout was retained, built-in furniture refurbished and reused, and suspended ceilings and light fittings sensitively renewed. The classrooms still have their original proportions and can continue to accommodate a diverse range of teaching situations. Despite a slight reduction in incidental light through the thicker window profiles required to hold the triple-glazing, the fact that the classrooms are illuminated from two sides ensures that the interiors are pleasantly bright. The range of spaces and learning group rooms that were originally conceived as part of the building design are still relevant for modern teaching concepts. Likewise, the central staircase has lost none of its communicative qualities, despite the fact that circulation is frequently a major sticking point in the design of schools due to the complexities involved in providing a second escape route. The architect responded to this problem by skilfully routing entry and exit, inserting a few internal glass walls and adding two open, external fire escapes. These new staircases are so restrained in form and colour that they are barely noticeable.

The conversion succeeds in retaining much more than merely the structure and shell of the old cross-shaped building. Its facades have largely retained their proportions and only the slightly thicker window profiles – a simple cost decision – no longer correspond to the appearance of the original.

Originally published in Bauwelt 47.2015, pp. 30-33, abridged and edited for Building Types online, translated by Julian Reisenberger

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