Grey Warden Vault

Prerequisites
In order to access the Grey Warden Vault, you must have told Riordan about the safety of Arl Eamon's estate. It is during this sequence that he makes you aware of the vault's existence.

After defeating Arl Howe, speak to Riordan in Eamon's state room. He will make you aware of the vault's location, though his directions are not clear and the location is not marked on your map.

Location
The location of the Grey Warden Vault is in the same warehouse involved with Solving Problems. Once you are aware of the vault's location, the door to the vault will be behind a shelfing unit.