Impact fees shall be imposed and calculated for the alteration, expansion or replacement
of a building or dwelling unit or the construction of an accessory building if the
alteration, expansion or replacement of the building or dwelling unit or the construction
of an accessory building results in a land use determined to increase the number of
dwelling units. The impact fee imposed shall be the impact fee imposed under the ordinance
for the building, dwelling unit, or accessory building after construction, alteration,
expansion or replacement, less the impact fee that would be imposed for the dwelling
unit type prior to such alteration, expansion, replacement, or construction.
