Is it possible to ID this from a photo (I suspect not)
No interactions present.
From the small number of caddis species I'm familar with, this one matches very well to Stenophylax permistus, but there are other related species that I haven't seen so not sure whether there are other possibilities as well.
Entomologist and biological recorder
I would tend to agree but you are right about related species. I am trying hard to find wing marking characters for this group of 4 species but failing so far.
Ian Wallace, UK Trichoptera Recording Scheme
Lat/Lng: 51.5, -0.4
OS grid ref: TQ1684