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 Article VI shall apply.
The following provisions shall apply whenever any improvement is made to an existing structure located within any identified floodplain area:
A. 
No expansion or enlargement of an existing structure shall be allowed within any floodway area that would cause any increase in the elevation of the one-hundred-year flood.
B. 
No expansion or enlargement of an existing structure shall be allowed within any FE area that would, together with all other existing and anticipated development, increase the one-hundred-year flood elevation more than one foot at any point.
C. 
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.
(1) 
The above activity shall also address the requirements of the 34 Pa. Code Chapters 401 to 405, as amended, and the 2003 IBC (Sections 3402.1 and 1612.4) and the 2003 IRC (Section 323.1.4).
D. 
Any modification, alteration, reconstruction, or improvement of any kind to an existing structure, to an extent or amount of less than 50% of its market value, shall be elevated and/or floodproofed to the greatest extent possible.
E. 
Any modification, alteration, reconstruction or improvement of any kind that meets the definition of "repetitive loss" shall be undertaken only in full compliance with the provisions of this chapter.
F. 
The requirements of 34 Pa. Code Chapters 401 to 405, as amended, and the 2003 IRC (Sections 102.7.1, R105.3.1 and Appendices E and J), or the latest revision thereof, and the 2003 IBC (Sections 101.3, 3403.1 and Appendix G), or the latest revision thereof, shall also be utilized in conjunction with the provisions of this section.