Section 231(1)

(1) If any part of a building abutting
on a public street is within the regular line of that street, the Commissioner, may, whenever
it is proposed to repair, remove, construct or reconstruct or make any additions to, or
structural alterations of any portion of such building which is within the regular line of the
street by any order which he issues concerning the additions to rebuilding, construction,
repair or alterations of such building require such building to be set back to the regular line
of the street.