The booming southwest area of Salt Lake County had the biggest jump in assessed property values, where appraisals are 28.6 percent higher than last year. Salt Lake County's smallest change in property values was in the East Millcreek area, with a 13.9 percent increase.

On the whole, Utah County's assessed property values increased by 25 percent in the past year. Just last year, the average home in Utah County was assessed at $203,000; today the average value hovers around $253,000, Utah County Assessor Kris Poulson said.

That's not to say that real estate sales figures will show the same data, however. Poulson points out that, according to multiple-listing service data, the average for single-family homes sold in Utah County was $217,100 in 2006; this year the average was $261,300, for an average increase of about 20 percent.

Utah County resident Mary Louise Sargent said she doesn't agree with those figures or any other numbers that suggest that the worth of Utah homes has legitimately skyrocketed.

"I think the whole real estate issue in Utah is inflated, highly inflated, and at some point it's going to have to come down," Sargent said. "It's just outrageous and unbelievable."

Sargent said she and her husband are planning to appeal their assessment, which they received last week, to the Utah County Board of Equalization.

The general rise in property values across Utah County helped offset any major spikes for any one particular city this year, Poulson said, so fewer people should have sticker shock when they compare their tax notices to their neighbor's.

The appraisal process

County appraisers must put a value on your home every year.

But it's not a simple process. Appraisers don't visit every single home before making a determination on your property value. Utah law only requires a review of property characteristics once every five years.

"We don't have enough people to look at 328,000 parcels a year," Burgi said.

Instead of yearly, personal visits, assessors rely on complicated computer models to appraise property.

Imagine a neighborhood with a typical 1,500-square-foot rambler with a finished basement.

The computer models can analyze other homes in the neighborhood, such as a nearby home measuring 1,400 square feet without a finished basement and another home measuring 1,600 square feet with a three-car garage.

The two homes' distinguishing factors are weighed against the typical 1,500-square-foot home, and values are assigned.

"(But we don't) just throw the data into a hopper and walk away," Ivie said.

Assessors then check for anomalies, as the model isn't always perfect, Salt Lake County Assessor Lee Gardner said.

"If we see some areas that look abnormal, we'll send someone out," Gardner said.