Straw-roofed homes like this used to be the norm around here, and a few still remain in every town. They would not work in a dry climate, and they have to be updated every ten or twenty years, but there is no cheaper or more sustainable roofing material. After a while, moss grows on the roof, adding to the protection and the charm.
Hearteningly, a number of the dilapidated thatch cottages near our home have been restored recently, and I have seen entire hillsides of new thatch roofs in County Clare. There are few thatchers left, but they have had good business lately, and their numbers might increase as the method returns.