Owners of the 2,583 single-family homes in Warren may be in for a surprise when they open the mail this week: News that their home may have lost 8 percent or more of its value.

The town this week is sending out notices of its recent statistical revaluation, in which every property in town — public or private, taxable or tax-free — was assigned a new value for taxing purposes.

Appraisers from Northeast Revaluation Group LLC, the town's contracted assessing firm, used sale figures, building permit records and other indicators to assign new values to each property. While some took big hits, others declined less in value. The average decline was 8 percent.

What does that mean for the average homeowner? Using an expected tax rate of $18.54, owners whose homes decreased in value at or close to the average will likely see little change in their tax bills. Those whose properties decreased in value more than the average may get a tax cut, while unlucky residents whose properties loss less than the average, or even gained value, will likely see a tax hike.

Here is a breakdown of what some of the numbers mean:

Single family homes

Warren's largest real estate category, single family homes are worth a collective $644 million, down from $693 million the last time the town completed a revaluation three years ago.

Bob Battey, who led the revaluation team for Northeast, said that while the average drop in single family homes was 8 percent, Warren saw wide fluctuations in value change depending on location. Waterfront locations and desirable spots like Touisset tended to hold their value more than the average, while other spots showed a more dramatic downturn in value.

The toughest place to own a home, value-wise, could be the north end and "older" part of town, including the Water Street area. During the town's last revalution, Warren Tax Assessor Cathy Maisano said, Water Street was "booming." Not so now.

"There was a lot of speculation about what was going to happen with the Tourister, with the economy," she said. "Then the bubble burst, and now there's not a lot of interest in Water Street."

It's not just Water Street, Mr. Battey added.

"Older neighborhoods, for instance all along Main Street, your older properties in more established areas, had a tendency to decrease in value more because of their age," he said. "Obviously the Touisset area held its value well, and waterfront areas. But you can go down Market Street or Child, and the north end of Warren, and you would find that those areas have bigger declines in value."

The flip side of that, however, is that if owners in those areas do not plan to sell they may see little impact on their tax bills, or even see a lower bill depending on how much value they lost.

Rental properties

Apart from vacant residential homes, which on average lost 17 percent of their value, the largest decline in properties across town came in two to five-family rental units. On average, those units — there are 625 in Warren — lost 16 percent of their value.

Mr. Battey believes the sharp drop in this category is due to the overall economy and difficulty owners have finding good tenants.

"The problem is that because of the economy, you can't raise rents. Every time expenses goes up and they attempt to raise rents, they lose tenants," he said. "In many cases they are forced to reduce rents in order to keep good tenants.

This becomes a problem when owners try to sell.

"People are having a more difficult time selling their rentals," he said. The difficulties with rents and tenants "does make investment property harder to sell, and from that point of view people who buy investment property and can't rent it, sell it at a reduced rate and lose money."

Not all bad

The news is not all bad, however. Though property lost value this reval and during the last one three years ago, the rate of loss is slowing. If the trend continues, could flip by the time the next reval comes around in three years.

I suppose the good thing, as opposed to several years ago, is residential is down less, condos are down less. Property values are down less, in general," he said. "It's fairly reflective of the whole market in general. Things show signs of improving."

Compute your bill

Property owners this week will receive new assessment figures for their properties from the Town of Warren. Town tax assessor Cathy Maisano cautions residents, though, not to use last year's tax rate to compute their new tax bills. Instead, she said, use the town's new estimated tax rate, which takes into account Warren's revaluation. The new estimated rate is $18.54, though a rate won't be set until after the town's budget is set, the new tax base is ratified and voters approve it all at Financial Town Meeting in May.

To find your new estimated tax bill, divide the new value of your home by 1,000 and multiply that amount by $18.54.

Residents who have questions about their revaluation, or who want to dispute it, can arrange to speak to experts from Northeast Revaluation Group, the town's reval firm. Instructions on talking to an expert should be listed on the letter mailed this week from the town.