The base amount of any owner-occupied single-family dwelling or nonagricultural property may be further increased above the limitations provided by section 3 of this Act, if there is a change in the use or classification of the property, or to account for any addition or expansion to the property. An addition or expansion to the property may only result in an increase in the assessed value above the limitations provided by section 3 of this Act by the difference between the real property with the addition or expansion and the real property as if no addition or expansion was made. The renovation of existing structures does not constitute an addition or expansion of the property. 29