In the early middle ages, when much of France was covered in dense forest, the houses were built of the most readily available material - wood.
One of the most unusual styles found is the 'maisons a empilage' style of architecture - literally this means 'piled up wood'. It is believed that these houses were all built within a short period of a few years, although evidence about their origins is almost non-existent.
The houses, of just one room inside, are built on a low stone foundation wall (perhaps 30 centimetres high) that exists to stop the timber from resting on the floor, where it would become wet and rotten.
The walls are then built, simply by stacking great oak logs one on top of the other. These beams are hewn very roughly into beams (ie square cross section rather than round), and at the ends the beams interlock, holding the whole building in shape.
The gaps between the beams are filled with a lime mortar when necessary to help reduce pests and win from entering the building. This extra 'comfort' might be a new addition that the original occupants were unaccustomed to.
The nature of the construction means that doors and windows reduce the strength significantly, and in any case the tradition at that time was to have only very small doors and windows - so the properties tend to be rather gloomy!
The roofs and tiles would also been made from wood originally, although most now have clay tiles instead.
There are about 50 of these early houses remaining in France - the the northern Lot-et-Garonne region around Villereal and local villages is the best place to see this traditional French architectural style.
Happily their importance has now been recognised, and they are often now protected monuments, helping to ensure their future survival.
Unhappily they are also expensive to repair in the required manner, so many of these remarkable houses, witnesses to 800 years of history, are still in a perilous state.