UPVC.
Doesnt seem like theres any twigs or anything that can deform the seals to let water in, and they dont feel perished. I did think it was strange that water was coming in, and apparently the amount thats coming in is quite a bit. I wouldnt expect this from some heavy rain but i suppose if its heavy enough and going straight at the doors causing lots of run off then this might be it.
Would putting some stuff on the seals, like i use one my car for the black plastic, help it out in any way?