as shown in the drawing to be connected together at a plurality of juncture points 1 at each such juncture point a buffer 4 which will be described in more detail is connected to the frame structure to support a fabric like sheet 5 which may be a gas impervious plastic material which is draped over the frame 2 it will be observed in fig1 that the frame elements 6 are connected together at juncture points 1 to form the latticelike frame network 2 in three dimensional configuration extending from a base b the fabric like sheet material 5 is thus draped over the frame 2 as a canopy to form an enclosure and is secured along its bottom edge to the base b in any well known and acceptable manner in many such building constructions a source of air is provided at slightly more than atmospheric pressure to keep the sheet or canopy 5 slightly expanded and out of general contact with the frame structure 2 however there will be inevitably some engagement between the canopy or skin and the frame and heretofore this has been the source of a problem causing great wear and stress to the canopy 5 whether it be inflated or not at the juncture points 1 in keeping with the present invention such wear and stress on the canopy or skin is greatly reduced by the provision of a buffer 4 at each juncture point the preferred form of such.