Tristan Peatfield
From Tardis Wiki, the free Doctor Who reference
Tristan Peatfield is the first person other than Ed Thomas to be credited as a production designer on the BBC Wales production of Doctor Who. He held that credit on Amy's Choice and The Lodger, but prior to this he was credited with a variety of other positions, including set decorator and standby art director. The first episode on which he received a credit was The Runaway Bride and he was sporadically credited until Voyage of the Damned. He was next credited on The Vampires of Venice. Between these efforts, he was a longtime production designer on The Bill. He was also credited as the supervising art director for Under the Lake and Before the Flood.
