It was the base of Herrick's vampire clan, due to the fact that one of the most influential Vampires lived there over 400 years before. Bristol is England's 6th most populated city, and appears in every Being Human episode in Series 1 and Series 2. Mitchell and George moved to the house in the Pilot episode, although it is unknown if they lived in Bristol in the first place. Annie lived in the house in Bristol before her death, although she was not from Bristol originally.
In Series 3, Mitchell , George and Nina moved to Barry Island after Annie was forced to pass over to the other side by Kemp during the Series 2 finale. She later joined them in Barry when she was saved by Mitchell.