(1)If any part of a building abutting a public street is within the regular line of that street, the municipality may, whenever it is proposed -(a)repair, rebuild or construct such building or pull down such building to an extent, measured in cubic meters, exceeding one-half thereof above the ground level, or(b)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 order, as respects the additions to, or rebuilding, construction, repair or alterations of, such building, require such building to be set back to the regular line of such street.
