The invention relates to the construction and arrangement of wall components (4) which are to be attached to the posts (2) and spars (3) of a basic frame for machines, instruments, equipment and the like. These wall components (4) extend from the middle of one post (2) to the middle of another (2) and are supported on the upper faces of the posts and the spars (3) between them by their folded upper web (8). The side edges (9) of the web (8) extend to approximately the middle of the face of the post and then run obliquely (10) inwards. A section (5) covering the posts (2) at the top is recessed where the web (8) is supported. Running around the inside edge of the wall component (4) there is frame-like spacer (6), the depth of which determines the distance by which the outer wall (7) of the wall component (4) projects beyond the outside of the post.