A housing having three side walls and a cover is provided, wherein an opening for introducing a pipe is formed in one of the side walls. The side walls are arranged in a U-shape, with the opening being provided in the side wall forming the first side thereof, and with a pipe section that aligns with the opening being connectable to the second side forming the opposite side wall thereof. The cross-section of the pipe section, in particular its diameter, is larger or smaller than the cross-section of the pipe. As a result, the pipe and the pipe section can be slid one inside the other.