The provisions of this chapter do not require any changes or improvements to be made to lawfully existing structures. However, when an improvement is made to any existing structure, the provisions of § 58-34 shall apply.
The following provisions shall apply whenever any improvement is made to an existing structure located within any identified floodplain area:
A. 
Any modification, alteration, reconstruction, or improvement of any kind to an existing structure to an extent or amount of 50% or more of its market value shall constitute a substantial improvement and shall be undertaken only in full compliance with the provisions of this chapter.
B. 
The above activity shall also address the requirements of the 34 Pa. Code, as amended, and the 2009 IBC and the 2009 IRC.