It's a very simple way to make thatched roofs. Painted it will look somewhat like this.
Well, well. That grass mat thatch is extremely effective. I’ve seen lots of ways of modelling thatch (teddy bear fur, sisal, towelling, etc) but I think this is the most convincing way of doing it that I’ve seen. I might have a go at that myself. Vielen dank for the inspiration :)
Perhaps you should add a ramp or two for the defenders to get up to the walls.
Is your signature related to the runes found in the Hagia Sofia? ;)Could be.... :D