Basically, the software assumes that chimneys begin on the floor in which they are inserted and extend upwards through all upper floors and the roof. Therefore, when floors are copied, a new chimney is not created, instead the existing chimney in the floor of origin is extended by the height of the additional floor. A chimney is treated as a single object, but is split into sections, with a section for each floor and a section above the roofing, so that the various sections can be allocated different visualisation materials or textures.
The options for height set either an absolute height in relation to the floor in which the chimney is situated, or a relative height above the highest ridge of the roof defined for the current building. If a roof has several ridges and you do not want the highest one to determine the height of the chimney, then an absolute height has to be specified. Under structure you can specify the number and the dimensions of the vents, as well as an option for ventilation. Here it is important that the absolute dimensions of the chimney match the number and the length of the vents.
The 2D representation of the chimney in 2D plan views depends by default on the shape of the 3D model. Other representations can be allocated using 2D symbols from the catalog. A representation using a symbol file is automatically scaled to match the absolute dimensions of the chimney.