Abstract: A device for sealing openings in buildings is formed with a frame that can adapted or adjusted to the inner dimensions of the opening, and a sealing plate or panel that is fixed to the frame. At least one of the lateral faces of the frame that faces the opening in the building comprises an inflatable sealing element preferably running around the periphery. The sealing element is configured preferably as a flexible elastic sheath with an open cross-section and forms a closed chamber with at least one section of the frame.