The basic issue in the instant cause concerns the appropriate factors to be considered in the valuation of real property for tax assessment purposes where the land in question is zoned for less profitable uses as compared with neighboring lands zoned for more profitable uses.4
*311Section 2, Article XII of the Ohio Constitution, directs that “land * * * shall be taxed by uniform rule according to value.” The term “value” as used in this constitutional provision has been defined as the amount at which property could be sold to a willing buyer by a willing seller on the open market. State, ex rel. Park Investment Co., v. Bd. of Tax Appeals (1964), 175 Ohio St. 410, 412. In determining this amount, this court has held on several occasions that, for tax assessment purposes, all facts and circumstances which may affect the value of property must be taken into consideration. American Steel & Wire Co. of New Jersey v. Bd. of Revision (1942), 139 Ohio St. 388, 392; paragraph one of the syllabus in B. F. Keith Columbus Co. v. Bd. of Revision (1947), 148 Ohio St. 253.
Likewise, the General Assembly has provided in R. C. 5715.01 that the Commissioner of Tax Equalization “ * * * shall adopt, prescribe, and promulgate rules for the determination of true value and taxable value of real property by uniform rule * * *. The rules shall provide that in determining the true value of lands or improvements thereon for tax purposes, all facts and circumstances relating to the value of the property, its availability for the purposes for which it is constructed or being used, its obsolete character, if any, the income capacity of the property, if any, and any other factor that tends to prove its true value shall be used.”
Despite the fact that in Ohio taxing authorities must consider all factors affecting the value of property, this court has stated that “ [n] either the glories of the past nor the dreams of the future should befog the issue in the valuation of Ohio real estate. The test is single — its present true value in money. ’ ’ Fiddler v. Bd. of Tax Appeals (1942), 140 Ohio St. 34, 37. Thus, not every conceivable factor affecting present market value will be sufficiently relevant to merit consideration, and this court will remand decisions made by the Board of Tax Appeals it finds to be unreasonable. B. F. Keith Columbus Co. v. Bd. of Revision, supra.5
*312In tibe instant canse, this court must decide whether it was reasonable for the Board of Tax Appeals to consider the appraisal of appellee in establishing the present true market value of the property, given the fact that the city’s appraiser treated the property in question as if it were already zoned for its highest and best use (which in his opinion was a modified U-7 zoning classification), despite the fact that as of January 1, 1974, 3.04 acres of the property were still zoned U-l A-l.
Although the question concerning future zoning as a proper factor in determining the value of property for tax assessment purposes is of first impression in this state, this court held in State, ex rel. Park Investment Co., v. Bd. of Tax Appeals (1972), 32 Ohio St. 2d 28, that, pursuant to Section 2, Article XII of the Ohio Constitution, valuations of property cannot be limited to considerations of current use only, since other factors comprising market value such as “location and speculative value” are excluded.
Since the proper method of valuation in Ohio is based on the fair market value that the assessed real property would bring if sold on the open market, evidence of potential uses of the land under future zoning laws cannot be completely proscribed from the valuation process in all cases. Because the proper test of fair market value is what a willing buyer will pay to a willing seller, the record may show in a proper case that a willing buyer will pay more for property than its current zoning classification would justify.6 However, before the taxing authority may increase a taxpayer’s assessment to reflect this willingness of buyers to speculate, the record must support such conclusion. A belief on the part of the real estate appraiser that property is more valuable than its permitted uses indicate, without market data to support such belief, is insufficient.7
*313In the instant canse, appellants’ appraiser, ■ believing the highest and best nse of the property to be office development under a modified U-7 zoning classification, treated the 25.76 acres as if it were already zoned for such purpose. No evidence was offered to show that in the. past buyers were paying higher prices for property zoned residential in the hope of a future zoning change, or, that the city of Beachwood was rezoning property purchased for future development as a matter of course. In fact, the record shows that: (1) in sale No. 10 of appellee’s appraisal report, such sale was contingent upon rezoning of the property, and (2) that the city of Beachwood refused to rezone appellants’ U-l A-l properties to a higher permitted use until December 15, 1975, at which time it did not liberalize the density restrictions of U-7 zoning.
Therefore, it was unreasonable for the Board of Tax Appeals to consider appellee’s estimate of $1,438,639.78 in making its own determination that the fair market value of the property as of January 1,1974, was $966,000.
Appellee’s estimates were based on conclusions that were not shown to be reflective of present market conditions. Although speculative value of property may. be con-' sidered in a proper case, this is not that case.
This court reverses the decision of the Board of Tax Appeals and remands the cause to the board for revaluation consistent with this opinion. ■ ••
Decision reversed.
Celeerezze, W. BrowN and Locher, Jj., concur.' O’Neill, C. J., and Herbert, J., concur in the judgment. P. BrowN, J., dissents.This cause is limited to tax assessment proceedings only, and does not affect prior eminent domain cases discussing the appropriateness of future zoning as a factor to be considered in valuing property.
Given the circumstances of that case, this court held that corner influence was an unreasonable market factor to be considered in estimate ins the value of the land.
Smith, Issues and Problems in the Valuation of Real Estate, 30 N. Y. U. Inst, on Fed. Tax. 209, 213 (1972); International Association of Assessing Officers, Assessing and the Appraisal Process, 37 (2 Ed. 1968); Parvin, Market Approach to Value, in Encyclopedia of Real Estate Appraising 21, 22 (Friedman Ed. 1968).
See Hedberg & Sons Co. v. Hennepin (Minn. 1975), 232 N. W. 2d *313743,- where, in a tax assessment appeal, the Supreme Court of Minnesota rejected the appraisal of the county’s expert since he valued the property in question as if it were already zoned for its highest.and best use based only on his belief that development and future favorable zoning would come to the area soon.
See, also, Kensington Hills Development Co. v. Milford Township (1968), 10 Mich. App. 368, 159 N. W. 2d 330,