For the existing building, intended to serve as office premises, which, in terms of height, consists of ground floor + 1 floor + 2 setback floor, retrofitting works were performed, as well as an addition of extra floors and enlargement to ground floor + 3 floors (P+3E) and reconversion into areas intended to serve as teaching premises. The central row of reinforced concrete columns was demolished and replaced by two rows of steel columns, without though demolishing the slabs. The load transfer from the former columns to the new ones was achieved through an inventive uplifting system, our own concept.