Almost two years ago, Prince William County launched a generous program to encourage property owners to fix up their houses, apartments and businesses.

The program promised to be a win-win situation for everyone. Owners making improvements would get tax breaks worth thousands to millions of dollars. The county would boost economic development and revive flagging neighborhoods. The deal was available to 42,000 houses, 1,700 business and 30 apartment complexes.

But in the 20 months since the tax exemption has been available, just three property owners have taken advantage of it. A house in Brentsville, a small commercial building in Quantico and an apartment complex in Triangle have gotten top-to-bottom renovations in the past year--and their owners won't pay a cent in taxes on the properties' new value for 14 years.

"The changes are pretty dramatic," said county Finance Director Chris Martino, who oversees the program.

He acknowledged that the number is small, but said the program still might need a few years to catch on with property owners.

Prince William has received 36 inquiries about the tax breaks since they became available in January 1998.

The deal allowed Joseph Outland to increase by 40-fold the value of a 100-year old farmhouse in Brentsville he purchased last year. The dilapidated house, worth just $6,100 on a 10-acre lot he bought for $90,000, now is worth $242,700, county records show.

But Outland, a builder, is paying just $100 in property taxes to the county, a deal that will last 14 years under the tax break. The tab without the break: $3,000 a year.

"I went out of my way to find a piece of property to do it," Outland said. "I put an awful lot of effort into fixing up the house, but it was well worth it."

Settled into his newly renovated farmhouse, Outland sold his Manassas home last winter for $240,000.

The 30-year-old Shenandoah Station apartments in Triangle--newly named from the Belleau Wood Apartments after the property changed hands in January 1998--also are profiting from the tax exemption with a major face lift.

"Literally, we gutted out these apartments," said manager Melissa Peckhouse. "It's like night and day."

The three-level, 170-unit complex is getting balconies, patios and brick facades. Because the rehabilitation isn't completed, county officials said, it will be a few months before they can calculate what the owners would have to pay in taxes without the exemption.

The third property getting the exemption is a two-story, white commercial building on Fifth Street in Quantico, owned by Douglas and Marie Humston, county records show. The property is still under renovation.

The intent of the program was to head off the first hints of blight in some of the county's older neighborhoods, ensuring that the highest real estate taxes in the state would not thwart redevelopment efforts.

Houses up for renovations must be at least 15 years old, business properties at least 20, and hotels or motels 35 to qualify for the tax break. Owners with delinquent tax bills are barred from applying.

The property must be improved enough to increase its value by at least 25 percent. For every $100,000 in value added to the property, the owners will save about $1,300 in annual taxes, Martino said.

Unlike the handful of other Virginia jurisdictions that offer the tax break, Prince William places fewer restrictions on it. There's no cap in the amount of added value eligible for a break. Property owners could, in theory, raze a property and build something new from the ground up--and still qualify.