A multi-element housing is disclosed for the containment of multiple membrane separation elements in parallel. The multi-element housing is characterized in that the elements are grouped in parallel with a feed/retentate zone, defined by a space enclosed by two tube sheets arranged at the same end of the elements. The central mandrels of the elements pass through the feed/retentate zone space defined by the two tube sheets and empty permeate outside the defined space into a permeate collection zone from which it is removed, while the tube sheet directly attached to the element is in open relationship to the interior of the membrane element and retentate accumulates in the space between the top tube sheet and the bottom tube sheet from which it is removed.