Text description provided by the architects. The Hambach open pit located approximately 40 km west of the City of Cologne, which is 299 metres deep and covers an area of 8,500 hectares, is the largest lignite surface mine in Germany. Approximately 40 million tonnes of brown coal are extracted from here each year. The Fo¬rum:ter¬ra nova that was built at the future boundary of the surface excavation zone will serve as an information and exhibition centre about surface mining and as a café and event site for the surrounding communities. It was built on behalf of the company RWE Power AG and the design was the winner of an international competition.
The purpose of the building prompted us to take on topography in an architectural context: the facade of the forum consists of filled, coloured concrete layers and resembles a cross-section through differently coloured layers of earth and coal seams, which can also be seen near the Forum:terra nova: the earth crust at the surface excavation cut several hundred metres deep gives an insight into the age of dinosaurs about 5 to 25 million years ago.
Inspired by the motif of the layers we applied alternating colour pigments to the concrete gravel used for the facade, which resulted in seven differently coloured layers. When complete the facade surfaces were milled off in order to emphasize the impression of a rough, original block of rock. The inside is a totally different matter: in contrast to the rough outer surface you find perfectly formed smooth, exposed concrete surfaces complemented by wood, leather and glass installations.
Daylight enters through the boxed windows in the ceiling and illuminates the central, two-storey-high atrium with the café, the main hall of the foyer. Exhibition and lecture rooms are located on both sides of the atrium on the upper floor. They are linked by the "distant view passage", which is perforated by telescope-like round windows and opens up into a view of the surface excavation landscape.
With the asymmetrically arranged bull's eyes within an elsewise closed cube shape the building seeks the balance between retentiveness and the inviting openness of an information centre. The section of the building located above the ground is designed as a fully developed volume that stands freely on 14 adjustable independent foundations. These foundations can be adjusted hydraulically in case of any ground movements resulting from the surface excavation activities.