In five related proceedings pursuant to Real Property Tax Law article 7 to review real property tax assessments for tax years 1994/1995 through 1998/1999, the City of New York and the Tax Commission of the City of New York appeal from a judgment of the Supreme Court, Richmond County (Pesce, J.), dated October 5, 2004, which, after a nonjury trial, reduced the real property assessments on the subject property for each of the tax years in question.
Ordered that the judgment is affirmed, with costs.
*916At issue on this appeal is the value, for real property taxation purposes, of three power generation units and transmission facilities located on Staten Island. Consolidated Edison Company of New York, Inc. (hereinafter Con Edison), which owns them, and the City of New York, which taxes them, agree that the generation units and transmission facilities are specialty properties that must be valued using the reproduction-cost-new-less-depreciation (hereinafter RCNLD) method. However, Con Edison argues that the value of “functional obsolescence due to excess construction costs,” a type of depreciation, should be deducted from reproduction cost to arrive at the value of the subject property, and the City argues that such a deduction is improper. The Supreme Court agreed with Con Edison. We affirm.
Despite the shortcomings inherent in RCNLD valuation (see Matter of Allied Corp. v Town of Camillus, 80 NY2d 351, 356-357 [1992]; Matter of Great Atl. & Pac. Tea Co. v Kiernan, 42 NY2d 236, 242 [1977]; G.R.F. v Board of Assessors of County of Nassau, 41 NY2d 512, 514 [1977]), the RCNLD method is used for valuing specialty property because the preferred methods for determining value, comparable sales and income capitalization, fail to yield a meaningful result with respect to such property (see Matter of Great Atl. & Pac. Tea Co. v Kiernan, supra at 239-240; People ex rel. New York Stock Exch. Bldg. Co. v Cantor, 221 App Div 193, 197 [1927], affd 248 NY 533 [1928]). Nevertheless, RCNLD is merely a methodology, not an end in itself. “[T]he ultimate purpose of valuation, whether in eminent domain or tax certiorari proceedings, is to arrive at a fair and realistic value of the property involved so that all property owners contribute equitably to the public fisc” (Matter of Allied Corp. v Town of Camillus, supra at 356; see Matter of Commerce Holding Corp. v Board of Assessors of Town of Babylon, 88 NY2d 724, 729 [1996]; Matter of Great Atl. & Pac. Tea Co. v Kiernan, supra at 242), that is, the standard for assessment remains market value (see RPTL 306).
Although the City’s appraiser agreed with Con Edison’s appraiser that depreciation for functional obsolescence due to excess construction costs is properly deducted from reproduction cost in determining value, the City’s appraiser did not apply this deduction in his calculations based upon the conclusion of the Corporation Counsel’s office that the deduction was not permitted. That conclusion was incorrect. Depreciation for functional obsolescence due to excess construction costs is, where indicated by the facts, a necessary measure of “disutility diminishing in some way the value of the property” (Matter of *917Onondaga County Water Dist. v Board of Assessors of Town of Minetto, 39 NY2d 601, 605 [1976]; see Matter of Long Is. Light. Co. v Assessor for Town of Brookhaven, 202 AD2d 32, 42-44 [1994]).
Contrary to the City’s argument, Matter of Brooklyn Union Gas Co. v State Bd. of Equalization & Assessment (65 NY2d 472 [1985]) does not preclude consideration of depreciation for functional obsolescence due to excess construction costs in valuing specialty properties. The issue in Brooklyn Union was whether certain underground gas mains were specialty property (id. at 481). Finding that they were, the Court of Appeals held that valuation by the income capitalization approach was not appropriate. In reaching that conclusion, the Court rejected the argument that the distribution mains in issue could not be treated as specialty property because they could be replaced by newer, less expensive mains. Thus, while the Court reiterated that the proper way to value specialty property was by the RCNLD method, it neither defined the parameters of that approach to valuation nor held, as the City contends, that depreciation for functional obsolescence due to excess construction costs was precluded.
Also contrary to the City’s contention, the deduction allowed by the Supreme Court did not effectively value the subject property based on replacement cost. Replacement cost is objectionable as a method of appraisal for real property tax purposes because it measures future value, rather than value on the taxable status date (see Matter of Allied Corp. v Town of Camillus, supra at 360), which is the valuation issue for real property taxation purposes (see RPTL 301). Depreciation for functional obsolescence due to excess construction costs, by contrast, adjusts reproduction costs to account for reductions in the value as measured by those costs due to changes in materials and technology (see Appraisal of Real Estate at 403 [Appraisal Institute, 12th ed]), and as such is an appropriate factor in determining the current value of a specialty property that would otherwise be overvalued by the use of reproduction cost alone (see Matter of Allied Corp. v Town of Camillus, supra at 356-357; Matter of Great Atl. & Pac. Tea Co. v Kiernan, supra at 242; G.R.E v Board of Assessors of County of Nassau, supra at 514). “The command of section 306 of the Real Property Tax Law that all property be assessed at full value does not pronounce an inelastic approach to valuation” (Matter of Merrick Holding Corp. v Board of Assessors of County of Nassau, 45 NY2d 538, 541 [1978]). That the amount of depreciation is calculated by comparing reproduction cost to replacement cost, *918or even that the calculation resulted here in a valuation equal to that which would have been reached on the basis of replacement cost, is not a basis to reject the methodology, at least in the absence of a reasoned valuation basis for doing so. The record here presents no such basis.
We also reject the City’s contention that consideration of depreciation for functional obsolescence due to excess construction costs was inappropriate here because the subject property was economically viable despite its technical and design inefficiencies. Complete lack of economic viability is not required before depreciation for functional obsolescence due to excess construction costs may be considered (see Matter of Long Is. Light. Co. v Assessor for Town of Brookhaven, supra at 42-44). Contrary to the City’s contention, the authorities upon which it relies do not compel a contrary conclusion. Barber & Bennett v State of New York (34 AD2d 303 [1970]) and Congregation of Sons of Israel v State of New York (54 AD2d 794 [1976]), in addition to being condemnation cases, hold only that “there can be no rigid rule as to what facts will require a finding of obsolescence as a matter of law, but that each case must be considered upon its own facts on this issue” (Barber & Bennett v State of New York, supra at 307), a showing which the state did not make in either of those cases. Matter of Niagara Mohawk Power Corp. v City of Dunkirk Assessor (221 AD2d 912 [1995]) was affirmed on the ground that the court had properly stricken the petitioner’s appraisal reports “[b]ecause petitioner’s appraisers admitted to employing a series of improper deductions” (id.), not on the basis of any substantive determination made by the Supreme Court.
To the extent that it is relevant at all, the Niagara Mohawk case stands only for the proposition that a deduction for functional obsolescence due to excess construction costs was not appropriate in the circumstances presented there. Here, by contrast, there is no showing other than that such a deduction is appropriate, since both appraisers agreed that proper valuation of the property required the deduction. On this record, therefore, the deduction for depreciation as a result of functional obsolescence due to excess construction costs was appropriate.
Accordingly, the Supreme Court correctly reduced the tax assessments for the subject real property. Adams, J.E, Ritter and Spolzino, JJ., concur.