are sized to snuggly fit over the annular setting pins 103 to control the geometric placement of the modules fig4 illustrates the abutment of modular units 12 13 16 and 17 along matelines m 3 and m 4 and how tension tie rods 108 and 115 connect successive vertical stories of a modular building according to the invention modular units 12 and 13 are placed on top of respectively modular units 16 and 17 with corner columns 104 of units 12 and 16 and of units 13 and 17 in overlapping alignment but separated by connection plate 100 the precise alignment of corner columns 104 of modular units 12 and 13 with corner columns 104 of modular units 16 and 17 is assisted by annular setting pins 103 and column base caps 111 as described above floor purlins 114 of modular units 12 and 13 lie on top of ceiling purlins 106 of modular units 16 and 17 separated by connection plate 100 connection plate 100 is affixed to ceiling edge purlins 106 at connector angles 107 tension rods 108 extend through corner columns 104 of modular units 16 and 17 and through tension rod holes 102 in connect plate 100 tension rods 108 are threaded and are affixed to connection plate 100 using washers 110 and tie rod nuts 109 tension tie rods 108 extend upward beyond connection plate 100 into the interior of corner columns 104 in modular units 12 and 13 upper story tension tie rods 115 extend through tension rod holes 102 in a connector plate 100 which is affixed to the.