When you go to bed after Memory Block 2, you will notice your closet door is open. Press any button to get a piece of paper Desmond notes as a code. The code will unlock your bedroom door, which allows you to go out as often as you like after you go to bed, as well as to open the meeting room area. You can also pick up various items to unlock Lucy's password.
Complete the game and watch the entire credits. You will be given the access code for the computer attached to the Animus. Hack the computer to access an inbox, outbox, and deleted message. Look at the inbox and select the email about the conference room. You can go to the conference room and access it via the keypad.