In 2004, Altenau School in Borchen was extended by three classrooms, two specialist rooms, a library and a media library. The extension building, which runs parallel to Schulstreet, gives the school a strong presence in the Haarener street / Schulstreet area. At the same time it forms a spatial border to the school grounds to the south. 

The new building has been arranged as a single loaded composition over two floors. All the rooms are accessed via the corridors on the north side. The connection of the two storeys through galleries and airspaces create exciting spatial experiences and promote communication within the building. The long sides of the structure include large areas of glass and thus enable penetration of indoor and outdoor spaces with numerous vistas. The horizontal aluminium louvres, which run approximately two metres from the façade, protect the classrooms and specialist rooms facing south from direct sunlight.