The Fairfax County Office of Assessments has begun mailing notices of reassessment to county property owners.

The notices, which should all be sent by mid-April, are being sent only in cases where the assessment is being changed.

State law requires that real property be assessed annually, that assessments be at fair market value, and that properties of the same class and similar value be taxed similarly. Most property changes in value every year.

The Office of Assessments currently appraises the total value of Fairfax County real estate at slightly more than $13.9 billion. That represents an increase of $1.5 billion (11 percent) due to appreciation and an increase of slightly less than $975 million (7 percent) due to new constructions, remodeling, subdivision of land and rezoning.

While an average property that has undergone no change will experience an 11 percent assessment increase due to appreciation, county officials say, individual properties may vary widely around that average, with some having no increase or even a reduction while others may increase in value by as much as 30 to 35 percent.

Inquires concerning any assessment should be referred to the Office of Assessments at 691-2371 or visit the office on the fourth floor of the Massey Building at 4100 Chain Bridge Rd., Fairfax.