buildings were often two-storey and had higher walls. Details such as the layout of fenestration on the building drew from classical traditions. A few buildings in this style remain today. As the 20th century dawned, Swiss chalet style architecture was brought indirectly to Iceland under Norwegian influence. Prefabricated houses were shipped and erected in settlements in the Eastern Region and Westfjords. The buildings tended to be taller and with large windows, unlike anything of the styles that had prevailed in Iceland beforehand. Notable features of these buildings were the friezes above doors and windows, and eaves which projected out above the walls. Here the distinctive Icelandic use of corrugated iron (imported from England), in place of external cladding, was born. The Swiss chalet style was the dominant force in Icelandic architecture in the early 20th century. The use of timber was banned in urban areas after great fires in Reykjavík and Akureyri around this time. Concrete was first used on a major scale as a building material in this period and became extremely popular as an easy and economical construction material. The material has shaped Icelandic architecture from this period. With the arrival of concrete came the first qualified Icelandic architect, Rögnvaldur Ólafsson, who had at first designed in the Swiss chalet style but soon moved on to working in concrete. His first works in concrete resembled closely the stone buildings of earlier times. Characteristically urban buildings began to emerge, such as Austurstræti 16 (designed by Guðjón Samúelsson) which were concrete constructions. Guðjón went on to become the leading Icelandic architect of the time. Referencing traditional Icelandic architectural styles, he revived the gable-fronted house design in concrete. This influence can be seen in stylised form in the National Theatre of Iceland building, for example. Guðjón Samúelsson was also the designer of Hallgrímskirkja, one of the tallest structures in Iceland, which was modelled on cliff faces. Contemporary architecture The functionalist architectural style arrived in Iceland in the 1930s, brought by younger architects who would later have great influence on the urban planning of the country. Unusually, functionalism was not met with as much controversy as it was in other countries at the time. Early functionalist buildings in the country resembled those elsewhere in Europe, but conventional interior layouts being their differentiating feature. Many neighbourhoods were built up using the functionalist aesthetic as their guide. The buildings were made distinctively Icelandic with