In the Middle Ages, in Iceland people started to build turf houses after wood became scarce. These were Passive Houses, although they didn't have adequate windows or sufficient ventilation.
Timber crisis: In the 17th and 18th Centuries in Europe there was a shortage of wood which was due to extensive deforestation. The solution to this problem was found in the mining of coal. However, in Iceland this was not possible. As we know, necessity is the mother of invention: the icelanders quickly found out that well-insulated houses remain warm by themselves.