awesome pics. those remind me of a museums-visit when i was younger.
it was at a museums-village near the northsea, showing how people lived at swamps.
looked up for some pictures:
sodenhütte1.JPG
sodenhütte2.JPG
both were primary made out of soil. the roof was simply grown grass
lehmhuette.jpg
clay was used for this one. its from the 18th cnetury, but that style (without those windows) was used centurys ago