Does anyone know what shape and dimensions a hole in a door should be for swallows to be able to fly into a shed? Previously they were able to fly in through a window but this has now been changed. I'm anxious not to put the swallows off.
Any advice on working apertures would be appreciated! Richard
Maybe I can help. They nest in my barn but this year I can't leave the door open all the time . Last year I partially closed the doors reducing the opening and they were fine. So I am putting in a small hen house sliding door as near to the top as possible. These are in polycarbonate or aluminium with non rusting aluminium runners. You could put a sloping pelmet above to reduce rain ingress. They do need to fly in and out and their wingspan is about 12". Just for info they nest on ledges anywhere they please. Wonderful. Hope this helps.