W. Va. Code § 11-1B-18

(a) All property as defined in section three of this article shall be appraised at its true and actual value as that term is defined in subsection (i), section three, article one-a of this chapter.

(b) County commissions shall proceed in a timely manner to hold the review hearings and issue determinations in accordance with the provisions of this article and the guidelines and regulations of the Tax Commissioner. If all hearings have not been held, or completed, or determinations thereon have not been issued, by June 1, 1987, the Tax Commissioner shall deem the values appealed from, and the results thereof, substantially correct and the review procedures substantially complied with, for purposes of subsection (c) of this section. In such instances, the county commission shall proceed to hold review hearings and issue determinations in accordance with the provisions of this article and the guidelines and regulations of the Tax Commissioner, and shall complete all hearings and issue all determinations on or before August 1, 1987, at which time it is the duty of the county commissions to have all hearings held and completed, all determinations issued, and the results thereof reported to the Tax Commissioner.

(c) Upon completion of the review procedures provided in this article, and after certification by the Tax Commissioner to the Governor, President of the Senate and Speaker of the House of Delegates that, with the exception of those matters pending under subsection (b) of this section or in the circuit courts of this state or on appeal to the Supreme Court of Appeals, said review procedures have been substantially complied with and further that the results thereof are substantially correct, the final valuations arrived at, by, and through the appraisal process to establish value of all property for the year 1983, as provided for in article one-a of this chapter and by this article, shall be and the same are hereby directed to be used for ad valorem property taxation in the year for which lien would attach on July 1, 1987. Such valuations shall be adjusted and maintained by the assessor in accordance with regulations governing the appraisal of property for property tax purposes and instructions provided by the State Tax Commissioner to reflect consideration of such substitutions, alterations, accretions, improvements, additions, replacements, destructions, removals, casualties, acts of God, waste or like occurrences or circumstances, as well as economic and other factors which result in or cause an increase or decrease in the value of any such property or any other divisions, redivision or other change in such property since its reappraisal for the year 1983.

In the implementation of such values, the assessor of each of the several counties shall assess the property subject to ad valorem taxation (other than public utility property) in the manner and subject to the procedures for return, assessment, equalization and review heretofore provided in this code, at sixty percent of the market value less such exemptions and allowance for phase-in which may be applicable.

With respect to property, the market value of which has changed since the reappraisal, the assessor shall enter on the computer network provided for by section twenty-one, article one-a of this chapter, the basis of any change in value utilized in such assessment.

With respect to property not subject to reappraisal at the time of the reappraisal, or property on which improvements have been made, the assessor shall use as a basis for phase-in of the reappraisal, the statewide phase-in rate promulgated by the Tax Commissioner for like property.

(d) The Tax Commissioner shall be provided by the assessor with any information, findings, or reasons relied upon by the assessor in increasing or decreasing values as a result of economic or other factors if applied by the assessor to any species or class of property generally or uniformly.