There is an open window in the attic which they weren’t aware of. They live in an old Victorian house and couldn’t see the window from the ground!
Beauty is in the eye of the beholder.
Well done on getting the picture on Kay, something a bit bigger than wasps then! Off to have a Google, will come back in a while. Agree with Alan, Crow, Rook, Raven or could be Pigeon or Collar Dove, but us sure if they would build indoors, but looks like their type of nest.
Pete
Birding is for everyone no matter how good or bad we are at it,enjoy it while you can