The Deutscher Werkbund - the German Association of Craftsmen - held an exhibition in Stuttgart in 1927 that included houses and apartment buildings - the Weissenhof Estate - designed by German architects but also by architects from Belgium, France and the Netherlands. New construction techniques for domestic buildings were shown … here an open steel frame infilled with concrete blocks for an apartment building designed by Mies van der Rohe
Until the 20th century, the main materials for building construction in Europe were natural … so stone as a strong but usually expensive walling; timber for wall framing, roofs and architectural fittings including windows and doors. Natural materials were not of course always used in their found state but were modified or transformed by builders so sand for glass; plaster for covering internal and external surfaces; clay fired for bricks and roof tiles and, of course, lime for mortar and for cement. Perhaps the biggest change to the structural form and then, as a direct consequence, to the appearance of buildings in modern Denmark came with the more and more frequent use of concrete and steel … not just for industrial buildings but for housing and apartment buildings and for new large building types and particularly where high or wide and open enclosed spaces were wanted that were unencumbered by walls or internal supports.