— Order unanimously affirmed with costs. Memorandum: Supreme Court properly denied petitioners’ motion for summary judgment in this tax certiorari proceeding brought pursuant to article 7 of the Real Property Tax Law challenging the assessment increase of petitioners’ property as unequal, excessive and illegal. The tax assessment by the taxing authority is presumptively valid and the burden is on the petitioner to show by substantial evidence that the assessment is excessive, illegal or unequal (see, Matter of Adirondack Mountain Reserve v Board of Assessors, 99 AD2d 600, 601, affd in part and appeal dismissed in part 64 NY2d 727). Here, petitioners failed to tender evidence in admissible form "sufficiently to warrant the court as a matter of law in directing judgment” in their favor (CPLR 3212 [b]; see also, RPTL 720 [2]; Zuckerman v City of New York, 49 NY2d 557, 562). The conclusory averments in the affidavit tendered in support of petitioners’ motion, that the increase in the assessment of petitioners’ property was due only to a perceived change in the use of the property and was imposed *996selectively, were insufficient to defeat the presumption that the assessment was valid. (Appeal from Order of Supreme Court, Oneida County, Shaheen, J. — Summary Judgment.) Present — Denman, P. J., Callahan, Balio, Lawton and Davis, JJ.