Structural alterations, internal rearrangements and renovations may be made in a building or structure which is nonconforming because of its failure to comply with height, area, yard, off-street parking or other like requirements of this chapter, other than use, so long as the structural alteration or increase, internal rearrangement or renovation does not extend or enlarge the nonconformance of said building or structure. Enlarging the non-conformance for purposes of this section shall be viewed in a three-dimensional manner to take into account the impact on light, air and open space, as well as lateral dimensional requirements.