Nevermind, can't get the link to work. Its the building NEXT to the Rayburn building.

It's actually right next to the Rayburn. Try this view:

https://www.bing.com/maps?osid=75eb60ad-1d8a-4579-9255-9d69a953ce4f&cp=38.88756~-77.008186&lvl=19&dir=235.30698&pi=1.6833731&style=x&mo=om.1~z.0&v=2&sV=2&form=S00027