This modular office structure in the middle of Berlin’s parliamentary district was conceived for the German Bundestag. The building reacts to the complexity of its surroundings with great simplicity: a simple H-shaped plan mediates between the comb-like structure of the neighbouring Marie-Elisabeth Lüders House and the block-like nature of its adjacent urban fabric. The H formation creates two parts: while the southern one comprises a cour d’honneur through which the semi-public areas including a spacious staircase can be reached, the northern one – protected from the noise of the railway by a glass wall – houses a green courtyard, the main security area as well as most of the 400 offices. The offices have been designed as prefabricated modules made of solid timber. Window elements, a timber frame with thermal insulation and integrated sun protection as well as a substructure for the façade cladding of coloured glass are built into the module while it is still at the factory. Only the floor slab, the technical rooms on the ground floor and the central atrium will be constructed on site in prefabricated reinforced concrete. The material concept for the interior design follows the constructive logic of this hybrid construction; as the shell materials of timber and concrete will remain visible. Due to its modular construction method, the building is particularly suitable for deconstruction: individual modules can easily be demounted and then recycled at another location. The approximately 2,500 cubic metres of timber that will be used to construct the 470 modules will grow again over the next 15 years.