The sites under serious consideration for the new Homeland Security headquarters reflect a shift in federal building design from grand temples of democracy to unassuming suburban campuses and signify the rise of Northern Virginia as the center of the nation's national security apparatus.

Each of three buildings identified as top contenders by those familiar with the search is in a landscaped office park in Fairfax County -- two in Tysons Corner, the third in Chantilly. There is not a Corinthian column in sight. None of the three is closer than nine miles from the White House.

The Chantilly site, now unoccupied, most recently housed a telecommunications company, Alcatel. "It's a typical suburban office building," said one of the location's biggest boosters, Fairfax County Supervisor Michael R. Frey (R-Sully).

But if the Department of Homeland Security's interest in these relatively anonymous office parks comes as a surprise to some, others see Northern Virginia's coup as the culmination of the long-standing and flourishing relationship between the region and the defense industry.

With the construction of the Pentagon in the early 1940s -- followed by CIA headquarters in Langley in the early '60s -- the defense industry and Northern Virginia began to grow as one.

The Fairfax Chamber of Commerce took note of those institutions when it lobbied Homeland Security chief Tom Ridge last month with this pitch: "The unparallelled diversity [of] Northern Virginia's labor pool will serve the department well. . . . Many Northern Virginians boast a wide range of skills related to their experience in the numerous information technology, engineering/R&D, defense-contracting, aerospace and biotechnology companies based in our region."

It was still not clear yesterday whether another location could emerge. Also uncertain is whether the rented site would become the department's permanent headquarters or whether it might build a campus elsewhere.

A congressman knowledgeable about the search said the Chantilly location, on Conference Center Drive, is the likely choice. "Based on our internal investigation, the final decision has been made, probably for a location in Chantilly," said Rep. James L. Oberstar (Minn.), ranking Democrat on the House Transportation and Infrastructure Committee.

But real estate sources were less certain, and a department spokesman said last night that the field is still open. "No decision has been made, no lease has been signed, and nothing is final," said the spokesman, Gordon Johndroe.

Local governments across the region have lobbied for months to host the new department, created by the consolidation of all or parts of 22 government agencies. A workforce of 177,000 people nationwide is forecast, with about 10 percent based in the Washington area. Some 2,000 employees are expected to work at headquarters initially.

As news spread yesterday that one of the Northern Virginia locations probably would become the department's home, Democrats and others objected to the locations and the process by which they were selected.

"We are spending $250 million, a quarter of a billion dollars, for a 10-year lease. After 10 years, my friends, you could have bought this building," said Del. Eleanor Holmes Norton (D-D.C.). Norton added that such a deal would have every appearance of "a sweetheart lease."

Norton cited a District study that estimated the city stands to lose $342 million over 10 years if the department located elsewhere. She said that the decision "undermined the economy of the nation's capital" and that the city had been "cheated" in the competition. Federal leasing guidelines, she said, steered the project toward the suburbs by favoring office parks and did not take into account access to Metro.

A document laying out the Bush administration's plans for the office lease was signed Dec. 24 and "slipped under the doors" of House members after Christmas, when most offices were empty, Democrats complained yesterday.

Bypassing normal review procedures, Republicans rammed language approving a lease into a spending bill that the House approved by voice vote last night. They said the measure satisfies a 1947 law that requires all Cabinet agencies be based in Washington, "except as otherwise expressly provided by law."

House Democratic Whip Steny H. Hoyer, who represents Prince George's County and Southern Maryland, condemned the maneuver as a power grab by President Bush at the expense of the District, Maryland and members of Congress.

"This is yet another example of this administration taking steps to bypass the constitutional right of Congress to approve acts of the executive branch," Hoyer said.

If one of the Northern Virginia sites wins final approval, it would be the first time a Cabinet agency was established outside the District since the Department of Defense moved into the Pentagon during World War II.

"I'm not surprised that they may be choosing Northern Virginia. Tysons Corner was basically built for the defense industry," said Tom Nicholson, a partner in West Group, which developed much of Tysons.

Premium office space in the District costs about $37 per square foot; in Fairfax, where office vacancy rates are as high as 20 percent, the per-square-foot rate is about $23.

A spokesman for the General Services Administration, which manages federal real estate, declined to comment.

Traffic tie-ups plague all three Fairfax locations. The Chantilly site is near Route 28, which is snarled at rush hour; the gridlock at Tysons Corner is legendary.

"The federal government is proposing to add 17,000 cars to the rush-hour traffic on Interstate 66, Route 28, Route 7 or the ramps into Tysons Corner," said Laura Olsen, assistant director of the Coalition for Smarter Growth. "This would turn an already horrible commute into a traffic nightmare."

Local officials, however, said the Tysons and Chantilly sites are designated as work centers, the buildings already exist and the road system will catch up eventually. Improvements are already underway on Route 28.

Staff writers Spencer S. Hsu and Lyndsey Layton contributed to this report.

Del. Eleanor Holmes Norton (D-D.C.) speaks during a news conference called by Democrats opposed to a Northern Virginia location for Homeland Security. With her are Rep. James L. Oberstar (Minn.) and Rep. Jerry F. Costello (Ill.).This vacant office building in Chantilly could become the headquarters of the new Department of Homeland Security.