From his ninth floor office in Tysons Corner, Va., zoning lawyer Antonio Calabrese enjoys a commanding view of the extensive office construction boom under way in Northern Virginia, a development that has transformed the once remote Dulles Toll Road corridor into a mecca for high-tech companies — and generated voracious demand for real estate lawyers.

The 15-mile stretch running west from Tysons in Fairfax County all the way into Loudoun County has become one of the most sought-after corporate addresses in the country. As it attracted such big names as America Online Inc., MCI WorldCom Inc., the Oracle Corp., and Nextel Communications Inc., the region also piqued the interest of national real estate developers like Sam Zell of Chicago, Boston Properties Inc. of Boston, and the Trammell Crow Co. of Dallas.