I was going to say, it's in exactly the same style and design as all the other additions to the original asylum, and that they weren't building stuff like that in the 1940s.Hi.
I was a resident in this building in the early 80’s and I can fully understand your confusion in thinking that this building was part of the Sedgefield Community Hospital. This was situated very close to the afore mentioned hospital but it was actually part of Winterton Hospital. The building was known as the Forensic Unit and was set up by a Dr David Westwell a highly respected Forensic Psychologist. The unit was set up to accommodate a dozen adolescent males between the ages of 12 and 16 years old with psychological and mental problems. The unit was serviced by the main hospital who supplied meals and all other services. I remember myself and other boys having to hand wheel a large cart between the unit and the main hospital to pick up supplies. The Community Hospital buildings were directly behind the Forensic Unit they were like second world war buildings leading to the front of the Community Hospital and the main road between Fishbun and Sedgefield. Directly opposite the front of the unit was Fishburn Coke Works. It’s my understanding the Forensic Unit came about in the late 70’s by Dr Westwell. Following his death in 1986 the building was renamed the David Westwell Centre in his honour.
This is one of the annexes/isolation hospitals or another sattellite building of some sort from the original asylum, abeit probably a slightly later (but still Victorian) addition. Although why this alone should have been kept, who knows. I think the chapel is still there?