Abstract: A building module for a ceiling having heating elements incorporated therein. The module has the form of a closed unit which can be individually mounted and removed and which comprises a frame and plates arranged on two opposite sides thereof. Heat-emitting elements are protectively arranged in the space defined by said frame and said plates and element connecting means are accessible from outside the unit and are arranged, when a unit is mounted together with other similar units to permit the elements to be connected to the intended supply source via other units located between the source and said one unit. The unit is so constructed that when mounting the same in position adjacent a similar unit there is formed a downwardly open channel between the units which channel is intended to be closed by means of a separate cover member.