(a) Municipalities and counties which have adopted a comprehensive plan containing a capital improvements element are authorized to impose by ordinance development impact fees as a condition of development approval on all development pursuant to and in accordance with the provisions of this chapter. After the transition period provided in this chapter, development exactions for other than project improvements shall be imposed by municipalities and counties only by way of development impact fees imposed pursuant to and in accordance with the provisions of this chapter.

(b) Notwithstanding any other provision of this chapter, that portion of a project for which a valid building permit has been issued prior to the effective date of a municipal or county development impact fee ordinance shall not be subject to development impact fees so long as the building permit remains valid and construction is commenced and is pursued according to the terms of the permit.

(c) Payment of a development impact fee shall be deemed to be in compliance with any municipal or county requirement for the provision of adequate public facilities or services in regard to the system improvements for which the development impact fee was paid.