Some Zhuang areas in Guangxi are relatively homogenous, while elsewhere Zhuang villages are scattered between villages of other nationalities. Zhuang villages range in size from 20 to 2,000 persons, with a few larger communities that are traditional marketing centers located along riverways or a crossroad. Often, a village or cluster of villages traces its descent from a common male ancestor. In multilineal villages, houses tend to group according to surname (patrilineage). Newcomers to the area live on the outskirts, often at a considerable distance. Typical villages are located on a mountain slope facing a river. Under Han influence, most Zhuang have adopted the one-story brick house, but some retain the wooden-pile house common to other ethnic groups in the area: a two-story structure, with living quarters upstairs, and the lower floor serving as stables and storage rooms. Both styles nowadays have tiled roofs.