Study of the Iron Age is often dominated by the archaeology of houses and hillforts. The latter are dealt with in Theme 6, along with a consideration of settlement patterns. This theme considers the concept of the 'house' itself and the evidence from houses at a range of levels, from the roots of the evidence itself to broader aspects of its interpretation. This national-scale review cannot hope to offer a detailed analysis of the research needs of specific areas or house types; it is hoped that the topics addressed here represent the major ones, and encourage others to develop or react against them in specific areas.
Houses dominate what is seen today of the Iron Age landscape - the term 'house-scapes' is introduced here to convey something of this. There are thousands of later prehistoric roundhouses known across Scotland, and hundreds of them have been excavated, presenting a tremendous resource for studying the period. Within this is significant variation in architectural form and material, and attempts to identify social and regional variation in houses and settlements represent considerable challenges.
Circular buildings represent the vast majority of Iron Age structures in Scotland (as elsewhere in Britain but in contrast to the near Continent). They can vary in size from less than 7m to approaching 20m in diameter, although 'modest' proportions (c. 8m across) appear most commonly. It is hard to imagine that all served the same role in Iron Age settlements (Harding 2009, 275).
Any discussion of Iron Age settlement and society needs to start in the Late Bronze Age (Harding 2006, 79). Roundhouses were being built across Britain from c. 1800 BC (Armit 2003, 33), and over time gave rise to a diverse range of regional forms. These Bronze Age origins are notably not the case in parts of Atlantic Scotland (e.g. the Northern Isles), where cellular forms remained the vernacular style. The Iron Age roundhouse, however, is not a straight continuation of a Bronze Age prototype (Harding 2009, 144-5) but represents a development of the concept during a period of significant change in roundhouse architecture circa 800-600BC (Pope 2003, 2007).