that a sufficient number of panels 10 12 and 14 is chosen so that the compression ring 42 is totally encircled by the panels 10 12 and 14 and obviously the number of panels required will be a function of the diameter of ring 42 obviously at least one door panel 10 must be included in order that the building b may be accessed as best shown in fig7 building b is interconnected to building b1 which is likewise interconnected with a building b2 which is interconnected to a building b3 a passageway connector 104 is connected to each of accessways 90 the passageway connector 104 is of inverted u shaped configuration the passageway connector 104 has side edges 106 and 108 each of which includes a tongue which is received within the groove 94 in the outer edge 92 of each of the accessways 90 the passageway connector 104 is similar in construction to the panels 10 12 and 14 and is therefore of lightweight configuration and may be readily transported it can be noted in fig7 that the buildings b b1 b2 and b3 are each of a different size or diameter and yet the buildings are interconnected by means of passageway connectors 104 the passageway connectors 104 are each of identical size and configuration and are able to connect with adjacent accessways 90 because the accessways 90 are also of identical size and configuration the provision of identically sized and configured acccessways 90 permits this interconnection of buildings b b1 b2 and b3 and thereby permits expansion of the usable space of the individual buildings b b1 b2 and b3 and also permits passage therebetween the assembly of building b or for that matter buildings b1 b2 and b3 is easily and.