perimeter columns 33 to the underside of the peak of the roof thus the lower portion of the corner columns 31 and perimeter columns 32 and 33 provide a convenient anchor point for specialized reusable concrete forms 90 see fig1 for the basement wall 23 without requiring more than one set of columns from basement level to roof level these special forms 90 for the concrete basement walls or ground level slab where no basement is used are sized and coordinated at the factory they have bolt hole 91 and bolts 92 coordinated to threaded sleeves 31a on the perimeter columns so that installation at the building site is accomplished very quickly with no measuring or leveling required the forms are automatically in plumb condition columns can also extend vertically to heights of more than one story in such cases the center columns extend to a height terminating a sufficient distance above said perimeter columns to provide a slope roof a typical reusable concrete form 90 shown in fig1 is pre assembled in a factory with all necessary bolt holes 91 and bolts 92 coordinated to internal threaded sleeves 31a affixed to perimeter columns 31 32 and 33 sleeves 31a have a length that determine thickness of basement walls 23 and interior diameter approximately equal to that of hole 91 referring again to fig1 one vertical edge of special forms 90 designated as the receiving edge 93a is comprised of two plates 94 and so spaced as to leave an opening in between the opposite vertical edge of form 90 designated as protruding edge 93b is comprised of one plate 95 so positioned that at installation plate 95 inserts between plates 94 and is locked.