The 12-mile drive from Scarsdale, N.Y., to Greenwich, CT, is about 21 minutes, according to Google Maps.

That short distance equates to a huge difference in property tax rates - about twice as much in Scarsdale as they are in Greenwich. "It's a huge spread," says Peter Grabel, managing director of Luxury Mortgage Group in Stamford, CT, and a resident of Greenwich for 12 years.

A Greenwich house assessed at $700,000, for example, will have annual property taxes of $8,100, says Tod Laudonia, the city's tax collector. That's among the lowest in the state, Laudonia says.

A house of the same value in Scarsdale will have $15,687 in property taxes, based on 2013 tax levies of $22.41 per $1,000 of assessed value, according to the city's website. Scarsdale is in Westchester County, a suburban area of New York State with the highest property taxes in the country.

12 miles is just the beginning of savings

The 12 miles between Scarsdale and Greenwich is just one example of areas where homeowners can find big differences in property taxes by just moving a few miles. The services and schools may not be the same, and one area may be more rural than the other, but homes with the same assessed value will pay significantly different property taxes each year.

The annual savings is enough to sway some people from buying in a more affluent area and living only a few miles from the extra parks, greenbelts and other amenities that higher taxes may buy.

After the mortgage, property taxes are usually the second biggest cost of home ownership. Between 2007 and 20111, 60 percent of counties across the United States reported average property tax burdens of $500 to $1,500 per year, according to a study by the Tax Policy Center. Some areas in New York, New Jersey and Colorado have taxes five times the national average.

What drives property taxes up or down

Property taxes are often determined at a county government level, and help pay for services such as sewer, water, schools, parks, street improvements and other things that state taxes don't pay for.

In the Northeast, local municipalities, not the county, tend to decide property tax levels. Highly concentrated pockets of wealth in the Northeast can lead to more local autonomy in deciding what the property taxes should be.

Grabel, the mortgage expert who grew up in Scarsdale but now lives in Greenwich, says Greenwich has a lot of affluence, but it's a town without much debt and has big businesses contributing to its tax base. All of that allows Greenwich to keep its taxes low, he says.

"Scarsdale is a place where you have superbly manicured baseball fields, and it's certainly known for having excellent schools," Grabel says.

Some area of Greenwich, however, don't have street lights or sewer lines and homeowners need septic tanks. "You're a little more country-ish," he says.

Connecticut also doesn't have a county government, so individual municipalities set their tax rates and have a large hand in how many services they provide.

"It's a whole other layer of things that we don't have to pay for," Laudonia, the tax collector, says of the benefits of not having a county government requiring specific services be provided, and paid for.

"We're lucky to be a town that has an abundance of volunteers" to run city commissions and take on other responsibilities, he says, lowering the city's costs.

Other close areas with big differences in property taxes

Here are some examples of other areas in the country where property taxes differ significantly in only a few miles:

4 miles from Florham Park, N.J. to Livingston, N.J.

Only four miles separates these two towns, but taxes are almost double in Livingston what they are in Florham Park, says Anthony DellaPelle, a property tax attorney in Morristown, N.J.

A home assessed at $1 million would have $20,000 in annual property taxes in Livingston, compared to $12,000 in Florham Park, DellaPelle says.

Florham Park is in Morris County, N.J., an area that's just west of Livingston's Essex County, which is closer to New York City. Moving further west from New York can often mean more land, he says, and also lower property taxes than in Livingston.Towns with lower taxes are attracting more people in a tough economy, he says.

"Many have not only downsized, but they're moved to different towns because they can have significant tax savings just by moving two towns over," DellaPelle says.

18 miles across Lake Norman, N.C.

Crossing Lake Norman - a lake that's 34 miles long with 520 miles of shoreline in North Carolina - can be as short as 18 miles from east to west. The property taxes on the east and northeast sides can be double what they are on the west and northwest portions of the lake, says Frances Dawson, a real estate broker in the area.

The Lake Norman area encompasses four counties, seven towns and covers 60 square miles. Each town around the lake has a different governance and tax rate, Dawson says.

The west-northwest area has the lowest tax rates, ranging from 60 cents to 72 cents per $100 in assessed value. A home valued at $250,000 would have annual property taxes of $1,500 to $1,800 in this more rural area that's still bout 30 minutes away from Charlotte, N.C. Buyers get more home for their dollar on the west side, she says.

The east-northeast areas have tax rates ranging from 83 cents to $1.22 per $100 of assessed value. A home valued at $250,000 would have annual property taxes of $2,075 to $3,050. The area is more developed and has more options for dining, shopping and entertainment, but homes are often smaller for the same price on the opposite side of the lake, Dawson says.

"Most buyers opt for smaller home/lot along with the higher tax rate in order to be within 15 minutes of a greater number of lifestyle enhancing businesses and entertainment options," she says. "However, even those families choosing to live less expensively on the west side of Lake Norman are only 20-30 minutes from any place on the more developed east side of Lake Norman."

15 miles from Cobb County to Fulton County, GA

The Atlanta metro area is a large area, but drive 15 miles across the Chattahoochee River from Cobb County to Fulton County, and you'll find higher property taxes in Fulton County.

Based on a $500,000 home, a Cobb County homeowners would pay $5,712 in annual property taxes, versus $6,607 in North Fulton County. Go to Forsyth County, which is only separated by a single road from North Fulton, and the annual property tax on the same home is $4,345.

The difference is even greater for someone over age 62, points out Chris Lambrecht, author of the upcoming book "Living Among Friends, a Boomer's Guide to Housing." Homeowners in Cobb County are exempt from school taxes, but they aren't in Fulton, representing about 75 percent of the typical property tax bill, Lambrecht says.