Module for walls and free standing structure

Claim 1

A building module in the form of a hollow body defined by an upstanding surrounding wall formation of rectilinear outline, said hollow body presenting opposed front and rear outer and inner faces and opposed side outer and inner faces and having a generally planar upper and lower surface and a substantially constant wall thickness throughout the extent of any given face, a pair of matching depending lug formations presented respectively below the said lower planar surface in each of the regions of said opposed side faces only and wherein each said depending lug formation in the region of said front outer face is rearwardly separated therefrom an extent measured rearwardly along said lower planar surface less than the thickness between said front outer and inner faces so as to define a first recess formation and in the region of said rear outer face is forwardly separated therefrom an extent measured forwardly along said lower planar surface greater than the thickness between said rear inner and outer faces so as to define a second recess formation and with each said lug formation having an extent front to rear corresponding to the separation between said inner front and inner rear faces whereby when the lower surface of one such module is presented to the upper surface of another such module one of said depending lug formations so presented thereto is registrable within the other such module to extend between the front inner and rear inner faces and with said first and second recess formations engaging the upper planar surface thereof in offset aligned mating relation therewith and displaceable thereover throughout a range of offset aligned mating positions between the opposed inner side faces thereof.