(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--
(a) to repair, rebuild or construct such building or to take down such building to an extent exceeding one-half thereof above the ground level, such half to be measured in cubic feet; or
(b) 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.
(2) When any building or any part thereof within the regular line of a public street falls down or is burnt down or is, whether by the order of the Commissioner or otherwise, taken down, the Commissioner may forthwith take possession on behalf of [[the Corporation]] of the portion of the land within the regular line of the street therefore occupied by the said building and, if necessary, clear the same.
(3) Land acquired under this section shall be deemed to be a part of the public street and shall vest in [[the Corporation]] .