Ind. Code § 36-9-39-16
(b) The total number of lots shall be computed as follows:
(2) If all or any part of the sewage works is located within an area that:
(C) is subject to zoning restrictions that prevent an increase in the number of residences;
each parcel of land that is abutting on or served by the sewage works and that contains a residence shall be included in the total number of lots as if the parcel was a platted lot.
(3) Except as provided in subdivision (2), if all or any part of the sewage works is located in an unplatted area, the number of lots to be included in the total number of lots shall be determined by dividing:
(B) one hundred twenty-five (125) feet.
The result determined under clauses (A) and (B) shall be rounded to the nearest whole number.
(4) The front footage of property may not be used to determine the number of lots included in an unplatted area if the front footage:
(B) is restricted against usage because of:
As added by P.L.98-1993, SEC.10.