The Building and Construction Union (German: IG Bau-Steine-Erden, IG BSE) was a trade union representing building workers in West Germany. Construction workers in Germany were organised in the German Union of Building Trades until 1933, when it was banned by the Nazis. A new union was founded in October 1949, at a conference in Karlsruhe. It was the last of the sixteen affiliates of the German Trade Union Confederation (DGB) to be established, because of difference of opinion between the communist-influenced construction union in the British occupation zone, members of the South Baden and Bavarian union who would have preferred to remain independent, and restrictions on unions in the French occupation zone.