Directions from Route 66 to 28 North towards Dulles Airport. Take the Willard Road Exit.
WEST on to Willard Road.  Through one light (Lee Road) and then less then 1/2 mile to the last building on the left.   

Directions from Herndon/Reston:  Rt 28 South.
Pass Rt 50 to next exit, Willard Rd. WEST. 
 Go through one traffic light (Lee Road) and then less then 1/2 mile to last building on the left.

14805 Willard Road - Chantilly, VA 20151

For you visual folks, here is what you are looking for.