spiritof1776

Thought I'd add a thread because when I searched for walk-in biometrics info for the Alexandria VA ASC office on VJ not a lot came up. Just to let people know it is very easy to do an early walk-in here. The office is currently open Tues-Sun, 8am-4pm but check the USCIS website for up-to-date info. Also the website does not have any parking information but there is plenty of free parking right outside the building. You cannot take cell phones in so leave them in your car.
The ASC was very quiet (I went on a Tuesday). The first guard checks your ID and appointment letter (does not matter if you are early - even though the board above their head may say different!), you fill in a questionnaire (make sure you know your SSN if you have one) then you hand it all over again to a receptionist. Then there is a very short wait before the fingerprinting and photo. I think I was in and out in about 10-15min. Everyone was very efficient and friendly, plus it saved me an 8am appointment with bad traffic!

Did this, they were cool about it.

Just a quick update for anyone reading this post now or in the future.
I rang USCIS and I was told they were sending me a new biometrics appointment, each time I rang I made a point of double checking with the level two officer that the letter had a) been sent out again and b) to the correct address. Each time I asked they assured me that it had, so I decided to wait until I received the new letter. However, after receiving an RFE that was sent sometime after this letter was supposed to have been sent out a separate officer told me no letter was ever generated!
So I followed the walk in advice and the very friendly staff sorted it all out for me. If anyone comes up against a similar issue with biometrics, I would advise you to not to wait for any letters and try and do a walk in.
And thanks for all your help everyone.