For years I have made draught excluders from old trousers. I have them at all my exterior doors.
Simply cut off one leg from an old pair of trousers and insert it into the other leg. Work out the width of the door. Use the top part of the trousers to bulk out where necessary and sew up the ends - as neatly or roughly as you wish.
Hey Presto .... a draught excluder.
Ann Droid, anyone watched this? BBC 1



