MAY,John., Handmade Houses and Other Buildings. The world of Vernacular Architecture. Edit. Thames & Hudson. 2010.
p.92-93."The mountainous areas of western Fujian (southwestern province of China) are home to unique rammed ea. rth buildings known as tulou (large defensive structures designed to house and protect a family clan). UNESCO estimates that 20,000 tulou survive at 46 sites, of which about 1000 are yanlou (circular buildings that can exceed 10 m in height and 60 in diameter).
The tulou were built between the 13th and 20th centuries by the Hakka and other peoples of southern Fujian, to protect themselves from gangs of armed looters. These buildings, walled like fortresses, whose construction could last 7 years, have foundations of rounded rock and a base of large stones, covered with clay, that supports earthen walls up to 1.8m thick, reinforced with bamboo canes. The interior of the building is basically made up of a structure of wooden beams, platforms and columns, it houses about 250 cubicles, in which about 80 families live. In the center there is a community patio with an ancestral sanctuary, which is the nerve center of the community. Only one side receives direct sunlight. The façade of the adobe wall is smooth and only the upper floors have tiny windows protected by large overhangs of slate or clay tiles. In general there is only one main entrance, protected by a thick reinforced wooden door framed in a block of granite.
On the ground floor there are the community kitchens, under the barns, as well as the rooms for eating and washing. Steep stairs lead to the first and second floors, where the day rooms, bedrooms and also galleries are located. Food, clothing and valuables are stored on the third floor. A small family has a vertical row of rooms, a larger one may have two or three rows. Tulou were built until the 1960s, today, fortified buildings are prohibited in China. Some are still inhabited, but the majority of the Tulou clans have been spread throughout the State and currently live separately in different family units."