The Reichstag building in Berlin is the seat of the Bundestag, the lower house of the legislature. Originally built in 1884, it was heavily damaged during the infamous Reichstagsbrand of 1933, when the Nazis set it on fire. It was restored after the war and in 1999, to celebrate unified Germany, received its now-iconic glass dome, designed by British “starchitect” Sir Norman Foster.
In addition to being visually and symbolically interesting, the dome is an energy efficiency wonder. It serves to both light and ventilate the parliamentary chamber beneath it. A cone covered in 360 funnel-shaped mirrors descends through the dome to reflect natural light into the chamber below. The mirrors also allow visitors inside the dome to see what is going on in the chamber below.
To avoid direct sunlight or unneeded heat, an electronic sun-shade is programmed to rotate around the dome to block the sun based on the season and time of day.
Air is ventilated out of the chamber through the center of the mirrored cone, where it passes through a heat recovery mechanism that collects remaining heat before the air leaves through a round opening at the top of the dome.
Three hundred square meters of solar panels on the surrounding roof, plus two combined heat and power units that run on German biodiesel, provide 82% of the energy for the Reichstag and surrounding buildings.
Waste heat is stored as hot water in a reservoir 300 meters below the building, and can be pumped up to provide heating in winter or power an absorption cooling plant in summer.
These innovative energy efficiency measures have helped reduce the building’s CO2 emissions from 7000 tons to between 400 and 1000 tons annually. The building itself is like a power plant for the government quarter. A beautiful and iconic landmark, the Reichstag dome is symbolic of the German government’s commitment to clean energy and environmental sustainability.