This chapter shall not apply to any existing or proposed buildings,
or extension thereof, used or to be used by a public utility corporation,
if, upon petition of the corporation, the Pennsylvania Public Utility
Commission shall, after a public hearing, decide that the present
or proposed situation of the building in question is reasonably necessary
for the convenience or welfare of the public.
Should any article, section, subsection, paragraph, clause,
phrase or provision of this chapter be declared by a court of competent
jurisdiction to be invalid, such judgment shall not affect the validity
of this chapter as a whole or any part or provision thereof other
than the part so decided to be invalid or unconstitutional.
This chapter shall become effective five days after the date
of final passage.