210-3(D)(3)(d) Construction, rehabilitation, restoration, repair of a non-residential structure, interior renovations or interior finishes within an existing structure, or addition to an existing non- residential structure that was permitted prior to the enactment of this Section shall not be subject to the provisions of this Urban Commercial Corridor Overlay District, provided that such construction is on a lot of record and does not affect a change to more than 20% of the existing gross floor area of a permitted structure or 2,000 gross square feet, whichever is less.