By Katie Wilmeth, The Examiner

With the Dulles Corridor in Fairfax and Loudoun counties expecting to add more than 220,000 new jobs and 86,000 new households in the next 25 years, developers are clamoring to build new commercial and residential properties around the 11 future Metro stops.

“I think if Metro goes in, it’s wide open all over again,” said Gerald L. Gordon, president and CEO of the Fairfax County Economic Development Authority.

Currently, the first phase of the Metro — the first five stops in Fairfax County including four in Tyson’s — is scheduled to be completed by 2011.

Metro will create a similar situation to the opening of the toll road in 1984, he said, which initially spurred the tremendous growth in the Dulles Corridor.

In the Tyson’s Corner area alone, new office space could increase by more than 20 million square feet in the next 25 years.

But unlike the current Dulles Corridor — which evolved primarily into a commuter destination with hundreds of office buildings and large-scale campuses for big-name corporations — Fairfax County officials and developers say the new Dulles Corridor will be a pedestrian-friendly destination where families can work, live and play.

“We’re using the rail to create walkable communities,” said Patty Nicoson, president of the Dulles Corridor Rail Association. “That’s just as important as transportation.”

The new “transit-oriented developments,” as they are called in the urban planning world, will look similar to developments along the Rosslyn/Ballston corridor in Arlington and create a better balance between those who live and work in the Dulles Corridor, said Arthur C. Nelson, director of Virginia Tech’s Urban Affairs and Planning Department.

For example, in Tysons there are about 116,000 employees and only 17,000 residents. The Rosslyn/Ballston corridor has about 100,000 employees and there are about 70,000 non-single family homes in Arlington.

“Arlington has really set the national model for how to use developments that maximize these Metro systems,” he said. “If properly designed [the Dulles Corridor] could be as large or larger than the Rosslyn/Ballston corridor.”

Although the condominium market has been on the decline in recent months and is expected to continue its slide, many proposals in the corridor will be mixed-use developments with condos or apartments — not subdivisions of single-family homes.

But “all it takes is a small percentage of this rather large number to want to live at these rails stations to make them vibrant,” Nelson said. “You don’t even need 10,000 of these households to make a transportation-oriented development” a success.