This article is about the building materials and techniques used in the Mediterranean coastal area of the Iberian Peninsula between c. 600 and 200 BC, a period that corresponds approximately to the development of the Iberian culture in this territory. It mainly focuses on the northern area of that culture, the north-eastern Iberian Peninsula (present-day Catalonia), although some examples of sites outside this area, particularly to the S, in the present-day Valencia region, are also taken into account (fig. 1). Archaeological research in the study area and period has been quite intensive in recent decades and has yielded a large amount of data regarding architecture, settlement organisation and construction techniques. The Iberian culture had a complex social system characterised by, among other traits, a hierarchical settlement pattern with several levels, including towns, villages, hamlets and farms1. In spite of the differences in size and function, most Iberian settlements shared several common traits. They were totally or partially protected by defensive walls, sometimes enhanced by towers and moats. The fortification often served as the perimeter wall of the settlement and houses sharing party walls were built up against it. Other settlements were organised in rows or blocks of houses that always shared party walls and were separated by streets. The main construction materials were stone, earth, timber and plant matter. Walls were made of stone or, more frequently, they had a stone plinth and an earthen upper section. Similar techniques were used to build the walls of domestic, public and collective buildings, as well as structures such as defences. Roofs were made of timber, earth and plant matter. Earth, lime and stone were used for the internal finishings of the buildings, as well as for the fittings for domestic or artisanal use. Most of the main traits of Iberian urban plans and building techniques originated in the Late Bronze Age or in the Early Iron Age. However, when each technique was initially adopted varied according to the territory. The use of the different building techniques attested in the Iberian period, as well as their origins, are discussed here. Particular attention is paid to the question of their autochthonous or exogenous nature.