The replacement of any multiple-family dwelling existing prior to July 1, 1999, by a new multiple-family dwelling with an increased bonus density of 20% subject to the provisions of § 164-153.1. However, an historically significant structure may be replaced under this subsection only if said structure was destroyed by fire, windstorm, flood, explosion, any cause of nature or any other cause not attributable to the negligence or misconduct of its owner. For purposes of this subsection, an "historically significant structure" is defined as any structure that is:
(1)
Included in the survey of historic structures for Westminster;
(2)
Described in The Building of Westminster by Christopher Weeks;
(3)
Located in the local Historic District;
(4)
Listed individually in the National Register of Historic Places;
(5)
Is a contributing structure in the Westminster National Register District.