Your home may be a year older, but for taxpayers living anywhere in Fayette County, it's almost a certainty that your property tax bill will be higher this year than last, when your home was newer.

That's because property tax increases are built into the system each year due to the annual reassessment of property values by the county's Board of Tax Assessors.

But just because your house is reassessed every year doesn't mean it has been physically looked at and evaluated by a live county appraiser. That in-person process typically happens every five to six years, even though the goal is to visit every home in the county once every three years, said Chief Tax Appraiser Ellen Mills.

On the years a physical assessment isn't conducted, county tax assessors use a formula based on certain attributes of a home to calculate the home's fair market and assessed values. The system takes into account such factors as how many bedrooms and bathrooms the home has, and whether it has a screened-in porch, patio, pool or other similar amenity, Mills said.

The type of construction, such as brick or frame, is also considered in determining the final assessment of a particular home's value, along with any exterior features, Mills said.

The assessors office determines the monetary values of those attributes by evaluating home sales each year.

"That's where we get the uniformity from," Mills said. "It's fair."

A common misconception is that the assessors office takes the previous year's home value and applies a flat percentage to calculate the new assessed value for the home, Mills said.

"That doesn't happen," Mills said. "Applying a percentage across the board won't work."

In calculating the various values of property attributes, the assessor's office eliminates from consideration home sales not considered at a fair market value, Mills said, defining fair market value as "what a knowledgeable buyer would pay and what a willing seller would accept."

Some sales, for example, are between family members, adjacent property owners or others who might sell the parcel for less than it might get on the open market, Mills said.

Also eliminated from the pool of home sales are those which came in at a significantly higher rate than the fair market value, Mills added.

"Some people just aren't good negotiators," Mills said.

When an in-person inspection is conducted on a given home, the goal of each individual appraiser is to look at all of the factors that would enhance or negatively affect the sale of the property, Mills added.

That means if a house has termite problems, severe roof damage or another structural problem that could cost significant money to repair, there's a good chance it will affect the fair market value of the property, and its ability to sell, Mills said.

Appraisers don't always visually see such damage so they only know about it if they are informed by the property owner, she added.

Some problems are more obvious, Mills said.

"We look for anything that would deter a buyer," Mills said, such as a traffic problem that would keep the homeowner from getting out of their driveway at peak traffic times. "That's something a buyer would think about."

Although county tax appraisers don't get to physically observe every home each year, they do visit every subdivision to survey conditions and determine if there is any reason the value of those homes should increase or decrease, Mills added.

A subdivision near the Fayette Pavilion had a large number of sales under market value several years ago when it was first indicated that a Wal-Mart store would be located nearby at the northeast corner of Ga. Highway 85 and Pine Trail Road, Mills said.

Thus, county tax appraisers had to readjust the values of the property in the entire subdivision to compensate for that fact, Mills said.

There are similar pockets of land in the county where property values have gone down, but again that is the exception in Fayette County, Mills noted.

Some neighborhoods have such good markets that their assessment come in higher than similar homes in the county, Mills said, citing the Kedron Village area in Peachtree City as one area where homes are hot commodities.

Although older homes have depreciation rates calculated into their reassessed value each year, the appreciation of the home's value usually overtakes the depreciation, Mills added.

The overwhelming majority of the county's roughly 39,500 taxable parcels is residential, Mills said. There are only 1,700 commercial parcels, Mills added.

Although just 4 percent of the county's parcels are commercial, they account for between 15 and 17 percent of the entire tax digest, Mills said.

Homeowners can appeal the reassessed value of their property for up to 45 days after receiving the reassessment notice, Mills said. This year, 617 such appeals have been filed, she added.

The office doesn't keep a running list of how many appeals are upheld and how many have their assessed values changed either by the Board of Assessors or the Board of Equalization, Mills said.

"If somebody appeals and it's lowered, it doesn't make a difference to us," Mills said.