Section 499-G. Tax lien; interest and penalty

All taxes, with interest,
  required  to  be  paid  retroactively  pursuant  to  this  title   shall
  constitute  a  tax  lien  as of the date it is determined such taxes and
  interest are owed.  All interest shall be calculated from the  date  the
  taxes would have been due but for the abatement granted pursuant to this
  title  at  the applicable rate or rates of interest imposed by such city
  generally for non-payment of real  property  tax  with  respect  to  the
  eligible  building for the period in question.  When a provision of this
  title requires the payment of a penalty in  addition  to  interest,  the
  amount  of  such  penalty  shall be equal to the amount of interest that
  would have been payable pursuant to such  provision  had  such  interest
  been calculated at the rate of three percent per annum.