© Duccio Malagamba

In 1992 Foster and Partners was one of fourteen non-German practices invited to enter the competition to rebuild the Reichstag. The practice won the competition after a second stage in 1993.
The building s transformation is rooted in four issues: the Bundestag s significance as a democratic forum, a commitment to public accessibility, a sensitivity to history, and a rigorous environmental agenda.

As found, the Reichstag was mutilated by war and insensitive rebuilding; surviving 19th-century interiors were concealed beneath a plasterboard lining. Peeling away these layers revealed striking imprints of the past, including graffiti left by Soviet soldiers. These scars are preserved and historical layers articulated; the Reichstag has become a living museum of German history.
The reconstruction takes cues from the old Reichstag; for example, the original piano nobile and courtyards have been reinstated. But in other respects it is a complete departure, opening up the interior to light and views. Within its masonry shell it is transparent, its activities on view. Public and politicians enter together through the reopened formal entrance. The public realm continues on the roof in the terrace restaurant and the cupola - a new Berlin landmark - where helical ramps lead to an observation platform, allowing the people to ascend above the heads of their political representatives.

The building's energy strategy is radical. It uses renewable bio-fuel vegetable oil derived from rape or sunflower seeds - which, burned in a cogenerator to produce electricity, is far cleaner than fossil fuels. The result is a 94 per cent reduction in carbon dioxide emissions. Surplus heat is stored as hot water in an aquifer, 300 metres below ground; the water can be pumped up to heat the building or to drive an absorption cooling plant to produce chilled water; that too can be similarly stored below ground. The Reichstag s modest energy requirements allow it to perform as a power station for the new government quarter.
The Reichstag s cupola is also crucial to its lighting and ventilation strategies. At its core a light sculptor reflects horizon light into the chamber; a moveable sun shield blocks solar gain and glare. As night falls, this process is reversed. The cupola becomes a beacon, signalling the strength and vigour of the German democratic process.