Every Wilton property owner will soon get a letter from Vision Government Solutions Inc., postmarked in Massachusetts. Don’t toss it; it’s not junk mail.

It is a notification of a property’s most recent assessment as a result of the revaluation process that has been taking place a good part of this year. Vision Government Solutions is the company the town hired to carry out the revaluation.

The notices will include information about the assessment and explain how property owners may meet with an appraiser from the valuation company if they disagree with their result.

The meetings are expected to take place during the first two weeks of January.

Each assessment reflects 70% of a property’s value based on the real estate market as of Oct. 1, 2012. According to Wilton Assessor David Lisowski, property values have dropped about 20% since the last revaluation in 2007, just before the recession. That is average for towns in this area, including Redding and Newtown, and is probably not news for anyone who watches the local real estate market.

Mr. Lisowski cautions property owners not to apply the proposed assessment to the current tax rate.

“With an expected drop in valuation from the 2007 market to 2012, it doesn’t necessarily translate into a corresponding drop in total taxation for an individual property owner,” he said.

In fact, Mr. Lisowski could not say more about what types of properties have dropped more in value than others except that residential real estate took the brunt of the hit. Commercial real estate saw less of a reduction.

“Again, that is an approximation,” he said.

Revaluation is not about specific tax bills, and if property owners choose to challenge or dispute their new assessment, they will do it without knowing how, if at all, their individual tax bills will change. That’s because the mill rate will certainly rise in order to generate enough revenue for the town to operate.

The way a property owner should look at a new assessment, Mr. Lisowski has said, is to decide if it is 70% of what the owner could sell the house for. If not, that would be reason to request a meeting with an appraiser.

“One thing that will have a slight effect on overall real estate taxation is that a higher mill rate will be applied toward motor vehicles and personal property,” Mr. Lisowski said. “Those are valued at 70% each and every year.”

Revaluation is not about taxes directly, Mr. Lisowski said.

“The purpose of the revaluation is to equalize the tax burden where properties are changing over a period of time,” he explained. “When you look at that number … it is based on what those types of properties are selling for now based on what they sold for five years ago.

Property revaluation is required by the state every five years for that purpose.

Grand list

“The grand list will be less than 2007, there is no doubt,” Mr. Lisowski said. “Real estate makes up 85% of the grand list and if that has fallen by approximately 20%, we would expect the grand list to come down as well.”

The grand list for the years between 2007 and 2011 is based on those 2007 assessments, and the only real estate changes have to do with new construction and improvements made to properties.

Mr. Lisowski must complete the grand list and file it with the town clerk by the end of January. Property owners who wish to schedule a hearing with the Board of Assessment Appeals must file a “petition to appeal” with the assessor’s office by Feb. 20, 2013. The petition is available only through the assessor’s office, and will be available Feb. 1. The Board of Assessment Appeals will schedule hearings for March 2013.

The changes in relative assessed value, along with how much the 2013-14 budget spends, will affect property owners’ taxes starting in July 2013.