before the scientific theories which explain why they work. Vernacular architecture is also used for the purposes of local citizens. Culture The way of life of building occupants, and the way they use their shelters, is of great influence on building forms. The size of family units, who shares which spaces, how food is prepared and eaten, how people interact and many other cultural considerations will affect the layout and size of dwellings. For example, the family units of several East African ethnic communities live in family compounds, surrounded by marked boundaries, in which separate single-roomed dwellings are built to house different members of the family. In polygamous communities there may be separate dwellings for different wives, and more again for sons who are too old to share space with the women of the family. Social interaction within the family is governed by, and privacy is provided by, the separation between the structures in which family members live. By contrast, in Western Europe, such separation is accomplished inside one dwelling, by dividing the building into separate rooms. Culture also has a great influence on the appearance of vernacular buildings, as occupants often decorate buildings in accordance with local customs and beliefs. Nomadic dwellings There are many cultures around the world which include some aspect of nomadic life, and they have all developed vernacular solutions for the need for shelter. These all include appropriate responses to climate and customs of their inhabitants, including practicalities of simple construction such as huts, and if necessary, transport such as tents. The Inuit have a number of different forms of shelter appropriate to different seasons and geographical locations, including the igloo (for winter) and the tupiq (for summer). The Sami of Northern Europe, who live in climates similar to those experienced by the Inuit, have developed different shelters appropriate to their culture including the lavvu and goahti. The development of different solutions in similar circumstances because of cultural influences is typical of vernacular architecture. Many nomadic people use materials common in the local environment to construct temporary dwellings, such as the Punan of Sarawak who use palm fronds, or the Ituri Pygmies who use saplings and mongongo leaves to construct domed huts. Other cultures reuse materials, transporting them with them as they move. Examples of this are the tribes of Mongolia, who carry their gers (yurts) with them, or the black desert tents of the