HARRISON – Overall property values have risen from $196 million to $276 million after a recent refactoring by Parker Appraisals of Windham.

The new valuation, a nearly 41 percent increase, has caused the mill rate to drop from $17.40 per $1,000 of property value to $13.35.

Selectmen approved the new rate Tuesday, which includes an overlay of $33,261.

Town Manager Mike Thorne called the increase “substantial” and largely the result of huge jumps in recent years in the market value of shoreland property on Long and Crystal lakes.

Long Lake properties have, in many cases, doubled in value compared to their assessments after the last revaluation in 1996, Thorne said. Crystal Lake property values have also risen, but not as fast as values on Long Lake, he said.

In the refactoring, Thorne said, Parker Appraisals looked at the sale prices of town properties and compared those selling prices to current town assessments. In some cases, assessments were 50 percent lower than sales values. State law requires towns to keep their assessments within 70 percent of market value.

“The idea is to bring the values up to where property is selling for today,” Thorne said. Refactoring is an interim measure to stave off a more expensive revaluation process, in which appraisers go out and physically visit all property in town, he said.

Different percentage increases were used for different areas of town, and “across the board you increase by the same factor,” he said.