An Iowa Supreme Court ruling today could set a standard for county property tax assessors when they determine the taxable value of new buildings.

The court reversed two lower court opinions when it upheld a $99 million assessment of Wellmark Inc.'s headquarters at 1331 Grand Ave. Wellmark had appealed the assessment to the Polk County Board of Review, which upheld the assessment, then to Polk County District Court, where Judge Lawrence McClellan lowered the assessment to $78 million, resulting a property tax refund of nearly $1 million in January 2014.

McLellan made his determination based on comparable sales, cost and income approaches that are used in assessments. The appeals court said that the actual value of the building was difficult to determine in the light of the fact that there were sales to use to help determine the value of the Wellmark headquarters.

However, Polk County argued that the actual $150 million cost of the new building should have been given more weight in the earlier court rulings. Assessors used that cost in determining the value for tax purposes, maintaining that the Wellmark headquarters did not lose substantial value the day it opened.
 
Wellmark also has appealed a $99 million assessment in 2013 and a $101 million assessment in 2015.

Wellmark apparently will have to repay the refund it received in 2014.

Polk County Assessor Randy Ripperger said the Supreme Court ruling set a standard for his assessors when they determine the value of newly constructed buildings.