Norðurmýri, the first residential district to be planned beyond Hringbraut, was developed in 1936-40. Its street and building plan was largely influenced by the direction of the sun. The Norðurmýri buildings are characterised by under stated functionalist style, with a strong overall homogeneity, although individ ual houses are designed by different people.
Distinctive features of the functionalist houses of the Depression years are corner windows, concrete gut ters and shallow-pitched mansard roofs, covered in painted corrugated iron siding. The houses were originally coated with dark pebbledash or with mortar mixed with pulverised Icelandic rock (obsidian, quartz, Iceland spar). This technique was invented in 1933 in connection with the construction of the National Theatre.