A macro moth, the Scalloped Oak moth. (Crocallis elinguaria)
Resting it measured near 20mm across but in flight can have a wingspan of 32 - 46mm.
Not one I would like to meet indoors.
with iPhone 6s
with Canon M5 + macro lens
Both photos were cropped.
A bit of a surprise to see it there, in full Sun on a South facing door.
Especially as it is a night flying moth.
I would have expected it to be hidden away somewhere.
