(1) Residential property located in an area which was previously zoned residential but has been changed to a zone other than residential shall be appraised, assessed and taxed as if such property were in an area zoned residential as long as such property is continuously used by the owner thereof solely for residential purposes.
(2)  "Residential property" as used herein is defined as any tract of three (3) acres or less which is used by the owner thereof solely for residential purposes.