Thatched roofs are used throughout the world, but in the traditional Japanese house they have a very unique role: as I explained a few months ago, for cooking and heating is used an irori and since there is no chimney, the role of cleaning the air is fulfilled by... the straw roof, which acts as a giant smoke filter.
EXIF info:
Nikon D80
Lens: VR 18-55mm F/3.5-5.6G
Focal Length: 24mm
Aperture: F/5.6
Shutter Speed: 1/60s
ISO Sensitivity: ISO 100