Even though the activities in an institute of reciprocating engines are different to those in an institute of turbomachinery, it was suggested that a double institute be built from the point of view of economy and the limited number of suitable sites available. Walter Henn designed the present complex consisting of three independent buildings built in 1965. Although the three-storey teaching and research building with the same common-use rooms – drafting rooms, seminar rooms, library and offices – has the smallest volume, it forms the centre point of the complex. It is connected by glazed crossings to the test halls.
The set-back building with a square plan shape is reserved for turbomachinery, the adjoining side wing for reciprocating engines. The two research institutes are connected by a shared main entrance. The various possible testing arrangements of the institute were highly influential on the design and structural configuration of both test halls. The scope of the Institute of Reciprocating Engines' testing work on internal combustion engines covers test beds for sound insulation as well as engine ventilation, which are integrated as permanent systems into the building. The testing activities at the Institute of Turbomachinery on the other hand demand a high degree of flexibility in the floor plan layout and in the building height. In order to be able to perform the various series of tests efficiently anywhere in the building and bearing in mind that the test equipment has to be dismantled, reassembled or moved around fairly often, it was decided to do without fixed testing installations and to provide an extensive power supply system. All the buildings have a framed load-bearing structure with masonry infill panels; the connecting walkways are structural steelwork only. The exposed masonry of the test halls is constructed in manganese brown hard-fired facing brick, while the office building has a suspended rear-ventilated light-coloured exposed aggregate finish concrete facade.