Abstract: A joint assembly for a casing cell or the like, which may form the housing of an air-conditioning appliance serves to attach a plurality of wall members to respective adjacent wall members by means of joining elements of the tongue and groove type for enabling a detachable fitting, the adjacent wall members abutting with abutting faces inclined to the main surface of each wall member, wherein the tongue type elements positively engage the groove type elements provided in at least one of the abutting faces and defining an undercut edge for the tongue elements, and two of the wall members of the casing cell which are arranged opposite and rigidly connected to each other and receive the other moveable wall members by insertion in a rectilinear direction essentially perpendicular to an opening face defined between the rigidly connected wall members, at least one of the joining elements being resiliently deformable.