More than 2,500 properties could undergo significant changes in value for Clark County’s 2013 revaluation, according to preliminary analysis by the county auditor.

Auditor John Federer said of Clark County’s approximately 66,000 properties, 2,570 required adjustment in valuation — both increases and decreases — due in part to inaccuracies in the last reappraisal that resulted in a record number of appeals.

Property owners whose valuations could be significantly adjusted will get letters in the mail next week.

Federer said about 1,804 properties increased in value by about $5,000 or more since the 2007 reappraisal, and about 766 decreased in value by about that much or more.

“I’m not surprised just based on what has transpired since the last reappraisal and the energy the constituents have put forth to help us make sure our information is accurate,” Federer said. “People were really interested to make sure that what we have is accurate.”

The Clark County Auditor’s Office received more than 2,800 appeals of property values after the county’s 2007 revaluation under the administration of former Auditor George Sodders, a Democrat who later lost to Republican Federer.

After the revaluation, Sodders announced “inconsistencies” in the $1.2 million revaluation by Findlay-based Appraisal Research Corp. after a Springfield News-Sun investigation revealed disparities among the new values.

The appeals marked a record number for the county. And among the 11 counties in the state that had mass reappraisal in 2007, Clark County had the highest reported number of appeals, though two other counties had more parcels, according to News-Sun archives.

Sodders told the News-Sun on Friday that the number of complaints compared to the total number of parcels in the county is a small percentage error. He also attributed the number of appeals in part to the recession.

“There were a record number of appeals in Clark County and in other counties in the nation … But when was the last time we saw a housing bust and a recession as deep and as long as it was? We hadn’t seen anything like that since the Depression,” Sodders said.

“Clark County was spared compared to a lot of other markets, not just in Ohio but in the nation,” Sodders said.

In an attempt to ensure accuracy for the 2013 state mandated revaluation, Federer said his office spent the past 18 months gathering and analyzing data collected from field visits and from information provided by property owners.

“It’s imperative that we go into our 2013 reval with correct and accurate information,” Federer said.

Tanya Schilling, appraisal and technology director, said the most significant changes are a result of inaccurate information in the auditor’s database from the previous administration.

“From what we can tell, because we don’t know historically, because neither one of us were here for ‘07, it doesn’t appear that a physical inspection had taken place for that revaluation, with the number of changes that we have,” Schilling said.

Sodders said physical inspections were done in 2007 as required by law and dismissed claims by those that say otherwise as attempts to score political points.

“The law was followed. The discovery phase was done and not only was it done it was supplemented with our Geographical Information System to see what it looked like,” Sodders said.

As of last Monday, data collectors found 465 properties with new construction, and 224 had demolished structures. Inaccurate information about the size of the foundation of structures on property also was found. Data collectors visited properties to ensure accuracy, Federer said.

“There are some where there are structures on the parcel that have been there for a number of years, way prior to the ‘07 that we did not have, so I don’t know how you can go out and view the parcel and not see a building there,” Federer said.

Schilling said officials are still collecting data for the 2013 revaluation.

“This is just discovery. We’re just fixing the data from ‘07,” Schilling said.

Property owners who receive letters may review and discuss their property information in the auditor’s office during the “open book” period from 8 a.m. to 4:30 p.m. on weekdays between Sept. 17 and Oct. 5 in the A.B. Graham Building, 31 N. Limestone St.

To schedule an appointment, call the auditor’s office at 937-521-1878.