Judgment, Supreme Court, New York County (Stuart Cohen, J.), entered February 7, 1994, which granted respondent’s motion to dismiss this CPLR article 78 petition seeking, inter alia, a reduction of the real estate tax assessment on petitioner’s property, and order, same court and Justice, entered April 11, 1994, which, insofar as appealable, denied petitioner’s motion to vacate the above judgment pursuant to CPLR 5015 (a) (2) and (3), unanimously affirmed, without costs.
The proceeding was properly dismissed on the ground that petitioner’s exclusive remedy for the reduced tax assessment she seeks is a certiorari proceeding under RPTL article 7 (Kahal Bnei Emunim v Town of Fallsburg, 78 NY2d 194, 204). Petitioner’s claim that respondent’s assessment methods understate the exemptions he is entitled to under the J-51 program is not a challenge to the method employed in the assessment of several properties, but rather to an overassessment of a specific property that necessarily involved the mental observations and judgment of individual assessors in placing a value on petitioner’s improvement costs (see, Matter of Board *417of Mgrs. v Board of Assessors, 202 AD2d 417, 419-420, lv denied 83 NY2d 757). ”[I]n the absence of any legally mandated criteria, it is within the expertise and discretion of the Commissioner of Finance to ascertain fair market value” (78 S. First St. Hous. Dev. Fund Corp. v Crotty, 150 AD2d 218, 222 [Milonas, J., dissenting], revd on dissenting mem 75 NY2d 982). Also properly dismissed, on the ground of res judicata, was petitioner’s claim alleging violation of her due process and equal protection rights and seeking to compel respondent to implement uniform, reasonable and predictable assessment standards, the parties and issues concerning such assessment standards being identical to those in a previous article 78 proceeding (Matter of Barklee Realty Co. v New York City Dept. of Fin., 147 AD2d 994; see, O’Brien v City of Syracuse, 54 NY2d 353). Contrary to petitioner’s contention, the previous proceeding did adjudicate her constitutional claims on the merits. Concur—Sullivan, J. P., Rosenberger, Ross, Asch and Tom, JJ.