law: 79. Assessment in case of amalgamation of premises.
  If any land or building, bearing two or more municipal numbers, or portions thereof, be amalgamated into one or more new premises, the Chairperson shall on such amalgamation assign to them one or more number and assess them to property tax accordingly:
  Provided that the total assessment on amalgamation shall not be greater than the sum of the previous assessments of the several premises except when there is any re-valuation of any of the said premises.