Companions and where they basically live:

• Solas - The Cylinder of Judgement
• Vivienne - The Balcony of Self-Importance
• Sera - The Room of Hoarding
• Cullen - The Tower of Isolation
• Cassandra - The Yard of Frustration
• Varric - The Hall of Wild Tales
• Dorian - The Nook of Sarcasm
• Leliana - The Spire of Secrets
• Blackwall - The Barn of Brooding Hooves
• Cole - The Attic of Curiosity 
• Josephine - The Desk of Political Headaches
• Iron Bull - The Wall of Mad Chillage

Bonus: 

• Krem - The Chair of Standing
• Morrigan - The Garden of Cryptic Plotting