Edwardian semi with damp coming through attic gable end wall

Without actually looking at the area in question it's really impossible to say exactly what is happening

Difficult to say without thorough investigation however the fact that it's mainly around window could suggest that cavity has been bridged around window causing water egress through cavity and into internal wall in my opinion highly likely, failing that it could be leaks around the window ie insufficient sealing . As a rule of thumb anywhere that cavity is bridged is likely to suffer damp issues Hope this helps , kind regards Del

Fgc & sons ltd It has possibly been pointed poorly, but would need to view and spec it properly because if built in lime mortar it needs to go back in lime mortar.