The Icelandic turf house was the product of a difficult climate, offering superior insulation compared to buildings solely made of wood or stone, and the relative difficulty in obtaining other construction materials in sufficient quantities.

Iceland was fully forested when it was settled (except for the mountains and highlands), with forests largely of birch

Birch

Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

 trees. Birch timber is not well suited to large and complex structures, but nonetheless a frame could be made with it. This also meant that it was difficult for ships to be built; this culminated with a lack of vessels that could transport large cargoes (Iceland's harsh winters added to the problem by increasing ship maintenance and occasionally destroying them). Due to the lack of transport and Iceland's remoteness, importing foreign timber was not very common and mostly reserved for ship and church building. However, Iceland did have a large amount of turf that was suitable for construction.

Construction

The common Icelandic turf house would have a large foundation made of flat stones; upon this was built a wooden frame which would hold the load of the turf. The turf would then be fitted around the frame in blocks often with a second layer, or in the more fashionable herringbone style. The only external wood would be the doorway which would often be decorative; the doorway would lead in to the hall which would commonly have a great fire. Another interesting aspect of the Icelandic turf house was the introduction of attached toilets, which were communal, and the act of going to the attached toilet was often done in large groups.
The floor of a turf house could be covered with wood, stone or earth depending on the purpose of the building.
They contain grass on their roofs.

Evolution

Icelandic architecture changed in many ways in the 1000+ years turf houses were being constructed. The first evolutionary step happened in 14th century, when the Viking style longhouses were gradually abandoned and replaced with many small and specialized interconnected buildings. Then in the late 18th century a new style started to gain momentum, the burstabær, with its wooden ends or gaflar. This is the most commonly depicted version of the Icelandic turf houses and many such survived well into the 20th century. This style was then slowly replaced with the urban building style of wooden house clothed in corrugated iron, which in turn was replaced with the earthquake

Earthquake

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

 resistant reinforced concrete

Reinforced concrete

Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...

building.