I toured the Bundestag (Parliament) in Berlin as part of the Federation of Canadian Municipalities’ 2005 Energy Mission to Germany.
The original building is more than 120 years old. The dome was added and the interior retrofitted in 1999 when the capital of Germany moved from Bonn to Berlin. It was also one of the first buildings in Berlin to be retrofitted for energy efficiency after reunification, and took four years to reconstruct.
The glass dome and mirrored column floods the inside with natural light. The Parliamentary chamber is located directly beneath the dome and so as people climb the circular walkway to the top they can literally look down upon their politicians. What a great idea!
The dome and column act as part of the ventilation system, capturing the waste heat and reusing it in other parts of the building. Warm and cool air is also drawn through ducts below the Parliamentary chamber and is recirculated within the chamber for passive heating and cooling; there is no air conditioning system in the building.
A photovoltaic power plant supplies some of the building’s peak energy need and the majority of its baseline need. Heat from this solar electricity generation is used in winter to heat water circulated through pipes. In summer, the heat is used to run absorption coolers. Two natural aquifers below the building provide additional heating and cooling and all surplus energy produced by the building is stored in the aquifers.