The first photo shows the white-rendered gable end of my friend's semi-detached house, which had a loft conversion in 2013 before she bought it (you can see the newly constructed rear dormer behind). The other side if the semi doesn't have a gable end (see second photo), so she's trying to work out if her gable end is original (1937), or whether it was constructed at the same time as the loft conversion.
There are no conversion plans online because the conversion was done under permitted development (no permitted development certificate was applied for, but when a neighbour requested enforcement action, it was closed with no action).
The third photo shows the only bit of the gable that has exposed brickwork. It looks modern to me, rather than original, do you agree?