Setting back of building to building line or control line

17. If any building or any part thereof, erected before the appointed day, referred to in section 14, lines between the building line and the middle of a highway, the Highway Authority may, whenever any such building or part thereof has, either entirely or in greater part, been taken down, burnt down or fallen down by notice, require such building or part thereof, to be set back to the building line or control line. Explanation :-For the purpose of this section, "the appointed day" shall, with reference to any highway boundary, building line or control line, mean- (i) the day on which the notification is published in official Gazette under sub-section (2) of Section 12 proposing to fix such highway boundary, building line or control line; and (ii) if any modification is made in proposed highway boundary, building line or control line; the day on which the notification is published under sub-section (1) of Section 12 fixing such highway boundary, building line or control line.