www.ukbutterflies.co.uk

Spotted this in shade all day books and online have come to naught approx 40mm tip to tip.

I'd say a Riband Wave http://ukmoths.org.uk/show.php?id=4170. The red of the door may well make the colour stronger than the moth actually is, though they are variable in colour. There is a form without the dark band.

Thanks JohnR online search confirms.