A device, structure, use and method for detecting a leak in a building, particularly in a roof, and/or in a wall and/or a ceiling and/or a floor, particularly in a wet room, of the building, comprising at least one pipe in which a fluid can be conducted, wherein a suction device is in fluid connection with a first end of the at least one pipe. An absorbent material is provided and a second end of the at least one pipe is arranged such that the fluid can be removed from the absorbent material, and at least one measuring device for analyzing the fluid is in fluid connection with the pipe.