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 VII, § 76-7.02 of this chapter 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, enlargement, or change to the exterior layout of an existing structure shall be allowed within any Floodway Area/District that would cause any increase in the base flood elevation.
B. 
No expansion, enlargement, or change to the exterior layout of an existing structure shall be allowed within AE Area/District without floodway that would, together with all other existing and anticipated development, increase the base flood elevation more than one foot at any point.
C. 
Any addition, modification, alteration, reconstruction, rehabilitation, 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, and shall also address the requirements of the 34 Pa. Code, as amended and the 2018 IBC and the 2018 IRC or the most recent revisions thereof as adopted by the Commonwealth of Pennsylvania.
D. 
Any modification, alteration, reconstruction, rehabilitation, or improvement of any kind to an existing structure, excluding any addition 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, rehabilitation, or improvement of any kind occurring as a result of being repetitively damaged shall be undertaken only in full compliance with the provisions of this chapter.
F. 
Any addition to either a Pre-FIRM or Post-FIRM structure shall be undertaken only in full compliance with the provisions of this chapter, including elevating the lowest floor of the addition up to, or above, the regulatory flood elevation.
G. 
Within any Floodway Area/District (See Article IV, § 76-4.02A), no new construction or development shall be allowed, unless the appropriate permit is obtained from the PA DEP Regional Office.
H. 
Within any AE Area/District without floodway (See Article IV, § 76-4.02B), no new construction or development shall be located within the area measured 50 feet landward from the top-of-bank of any watercourse, unless the appropriate permit is obtained from the PA DEP Regional Office.