Towards the revival of half-timbered houses?
Highly aesthetic and impressive, these habitats are typically built from materials of natural origin and very insulating, such as wood, clay, straw and stone. If in medieval times the concerns did not revolve specifically around ecology and sustainable development, these days these are much more important arguments. Half-timbered houses are indeed resolutely ecological habitats and therefore paradoxically modern, meeting the latest requirements in terms of sustainable development.
A brief history of half-timbered houses
From Roman times to medieval “corbel”
Emblematic of the medieval era, the half-timbering was previously mastered by the Romans from the ancient times. The famous city of Pompeii and that of Herculaneum had several examples of half-timbered houses, the filling materials of which were made from dried lava from the nearby Vesuvius. It is also thanks to this same lava that some of these houses were preserved during the eruption of Vesuvius in the year 27 BC, imprisoned in a protective matrix.
The timber is then used during the Middle Ages and survives the Renaissance in the 16th century to cross any modern times until the nineteenth century. In the 14th century, shortly before the beginning of the medieval period, the replacement of the technique of "long woods" by that of "courtyards" allowed the development of a particular phenomenon: corbelled construction. The principle consists of slightly shifting each half-timbered storey a few centimeters forward on the street. Depending on the height of the house, it can thus be a double, triple or even quadruple cantilever, ultimately making it possible to gain several tens of decimeters or even more than a meter on the street.
The system made it possible to optimize the living area for fiscal purposes and to reduce particularly high taxes depending on the region. Particularly aesthetic and vectors of a certain social level, the corbelled houses also offered the advantage of avoiding rainwater runoff and thus protected the wooden framework.
A historical heritage
Often located in the city center, many half-timbered and corbelled houses still exist or have been completely renovated. Certain regions are particularly rich in it: Alsace, Normandy, Brittany, Anjou, Touraine or Bresse. Among the most beautiful medieval city centers we can mention Strasbourg, Colmar, Auxerre, Dijon, Angers, Tours, Rouen, Rennes, Vannes, Quimper and the beautiful city of Bourges, which number several hundred. In Paris, where half-timbered houses have almost completely disappeared in modern times, one of the oldest houses in the capital is half-timbered.
Dating from 1644 and located rue Volta in the Marais. Moreover, this type of construction is not specific to France. Over a million half-timbered houses have survived the ages and averted the firebombs of World War II in Germany, scattered throughout most of the country. Fine specimens can also be found in northern and eastern countries (Denmark, Sweden, Poland, Czech Republic), Great Britain, Italy, and as far as Turkey and Brazil.
An all-wood frame
The principle of half-timbering is simple, based on the use of two components, wood and most often cob, or plaster or even brick. The wood forms the framework of the building, the other materials being used to fill the gaps and to solidify the whole building. The word colombage literally means “beam in the wall”. Solid oak is most often used, offering in addition to its extreme resistance and longevity a particularly marked aesthetic character. The wooden frame of the house is placed on light foundations, such as stone flashings, used to strengthen the waterproofing.
Two techniques coexist. The so-called "long timber" technique uses long wooden posts that run parallel from top to bottom of the house, and perpendicular to form the floors. Spectacular, this technique is also painful to implement, both to install the posts and especially to handle them. Built in the Middle Ages in the very narrow streets of city centers, the houses left very little room for maneuver to the builders. Another simpler method, known as "timber courses", has therefore supplanted "long timber".
Much shorter and therefore more numerous posts are used to make the walls, allowing more original poses, at an angle or cross. However, the opposite of corbelled dwellings tended to reduce the space and the brightness of the already cramped streets of the city centers. From the Renaissance onwards, cities banned them one by one, Paris banning corbelled construction from the 17th century.
The cob filling
Once the framework has been completed, it remains to fill in the intervals, which represent the largest surface area of the habitat. The most frequently used filling material is cob, a mixture of clay, water and most often straw, but also horsehair or vegetable husks. The whole is mixed and takes the form of a white or beige mixture, which is none other than natural concrete, as opposed to concrete cement. Even if it is not load-bearing, the cob nevertheless has an important role in solidifying the building.
It also has many practical advantages for the home. The cob accumulates water and absorbs water and rejects it according to the hygrometry of the air, while remaining waterproof. It is also a good insulator, just like the wood forming the frame of the house. The set therefore provides very good thermal and acoustic insulation at home, retaining heat in winter and cool in summer, which nowadays represent ecological and economic advantages.
There too, several techniques existed according to the regions to implement the cob, the most astonishing of which is called the "ball" cob. Practiced in Alsace in particular, this method consisted of superimposing cob balls to form the walls. Currently the cob is most often applied by mechanical projection, less charming but much faster and less restrictive than manual installation. It is also possible to replace the cob with raw bricks coated with lime. The result can again be spectacular depending on the imagination and skill of the builders, with spaced or oblique arrangements, and all kinds of geometric patterns imaginable.
Modern and ecological half-timbered houses
Half-timbered houses have been enjoying a new lease of life since the early 2000s. There are several possibilities to afford a house of this type. The restoration of an old house certainly offers the framework of authenticity, but requires a very serious know-how, a good dose of motivation, a tidy savings and a no less vast patience. For ex-nihilo construction, the times are now for the so-called “post-beam” technique, which directly takes up the method of assembling half-timbered houses.
The framework of the habitat remains in wood, with large visible rectangular posts. The walls can be made entirely of wood, glazed surface or another ecological material, including cob, in this case directly inspired by the historical style.These modern half-timbered houses, although expensive, represent a particular market and fruitful. The aesthetic appeal and remarkable comfort are the arguments of choice, as are the ecological characteristics of these types of habitat.
Wood, cob, glass or even stone all constitute "ecomaterials", therefore clean materials (as opposed in particular to concrete), with insulating properties. They thus save energy - and money - and meet the legislative requirements of RT2012, which requires the construction of buildings with low energy consumption. As the future RT2020 will push ecological requirements even further by leading to energy passivity, historic half-timbered houses may well be assured of a bright future.