Section 48-49-40 applies to buildings that existed upon the effective date of this chapter as follows: (1) No reconstruction, alteration, or expansion may aggravate or intensify a violation by an existing building or structure that did not comply with SECTION 48-49-40 upon its effective date. (2) No reconstruction, alteration, or expansion may cause or create a violation by an existing building or structure that did comply with SECTION 48-49-40 upon its effective date.