The invention relates to a device for passing pipes or cables through an opening in a building. Said device comprises a sleeve-like housing that has an axial passage channel that is open at its opposite ends; bristles that are mounted on the walls of the passage channel in such a way that they are opposite each other and that are extended inwards in such a way that they mesh with one another in order to close the passage channel; and flexible strips of material that are mounted in the passage channel and that are coated with an intumescent material.