Here's a new Payday 2 trailer that explains the Safehouse.
"Join David Goldfarb -- Game Director of PAYDAY 2 -- as he takes us into the Safehouse, the aspiring criminal's sanctuary, where you will be able to hone the skills that will keep a good heist from going bad. The Safehouse also acts as players bragging rights -- you can spend cash on upgrading it, making it into your own crime nest. Players can see how much cash they have earned in their own personal vault and try out the customised weapons they own in their private shooting gallery. Pre-order PAYDAY 2 now to receive the Lootbag DLC."
Payday 2 is currently in Beta that started on July 24th, 2013, and is scheduled to be released worldwide August 27, 2013 for Xbox 360, PlayStation 3 and PC.