The E.ON Energy Research Center ERC is the new institute for energy research of the RWTH Aachen. As a distinct, cubical building it is situated on a plain that terraces into the existing gentle slope. The main entrance opens into a generous continuum of rooms, connected with one another by air spaces and stairwells. Five research institutes, seminar rooms, workshops, laboratories and engineering areas are spread across five levels, rounded off by work stations for those studying and visiting, as well as open kitchenettes. The underlying spatial idea pursues the principle of „overlapping sciences“ – the borders between institutes and storeys merge into a generously-appointed communication space. An innovative colour concept facilitates the optimal orientation inside the building. A high standard of the interior in terms of technical convenience, acoustics and sound insulation contributes towards the quality of the stay in the building, which boasts a consistently barrier-free design. Its multi-storey glass openings on either side of the concrete façades open up the rooms even visually and create lookouts. Efficient technology has been implemented for the energy supply, in line with the institute‘s credo, ranging from concrete core activation, geothermal energy and a combined heat and power unit, to a photovoltaic system and decentralised façade ventilation units.