Stonington - When property owners received their revaluation notices this week, many saw a substantial decrease in the values of their homes.

This is the first time since 2007 that the town conducted a revaluation, a time period during which real estate values plummeted and only recently have begun to slightly rebound. The town's approximately 10,000 properties were valued as of Oct. 1, 2102.

Tax Assessor Marsha Standish said this week that townwide residential property values have decreased 19 to 20 percent while commercial and industrial values have dropped 17 percent.

She stressed that these are averages and the value of an individual property is based on numerous factors.

The town appraises properties based on sales of comparable properties and then assesses them at 70 percent of their fair market value. That assessment is what property owners are taxed on once the town approves an annual budget.

Property owners cannot take their new assessment and multiply it by the existing tax rate to figure out their new tax bill because that calculation would produce an incorrect, much smaller tax bill.

This is because with the decrease in the value of properties, the town will need to increase its tax rate so it can raise the needed tax revenue to fund the budget. In addition, motor vehicle and personal property assessments still have to be included in the grand list of all taxable property in town. Finally, the Board of Finance has to adopt a proposed 2013-14 budget that voters then have to approve.

All property owners should have received their assessment notices this week. Those who have questions about their assessments or feel they are incorrect can make an appointment with Vision Government Solutions, the firm that conducted the revaluation for the town.

To schedule an appointment, go online at www.vgsi.com/schedules or phone (888) 844-4300 on weekdays between 9 a.m. and 4 p.m. The last day to schedule an appointment is Jan. 25. The PID number at the top of the revaluation notice is needed to book an appointment.

The entire 2012 revaluation can be viewed at www.vgsi.com or www.stonington-ct.gov.

If property owners are still dissatisfied with their assessment after their informal hearing with Vision Government Solutions, they can file a written appeal with the town's Board of Assessment Appeals on or before March 20.

j.wojtas@theday.com