Plenty of the houses in Longparish are thatched.  One of them has a roof line that drops very low to the ground on one side of the house with the door and windows on the other side.  That must be the side that gets more light.  The back side of the house seems to be very shaded with the result that there is a lot of growth on the roof.  It was covered in various lichens/mosses.  I wonder whether they degrade the thatch or actually provide an additional layer of insulation.