Guédelon: the Remarkable Reconstruction of a Medieval Castle

In the small village of Treigny, a crazy project is taking place: the construction of an exact replica of a 13th century castle, using only the same construction methods as in the Middle Ages!

The Guédelon construction project is an interesting example of sustainable building, because it relies on construction methods that are based on medieval castle building in terms of both methodology and resources. Natural materials, such as a self-made lime mortar, meet historically correct details, such as windows made of parchment skin. What began as a crazy idea is now, more than twenty years after construction began, among the most exciting building sites in Europe – and, while not the only one of its kind, certainly one of the most famous. What certainly sets Guédelon apart is the planners' constant reassurance that they are approaching all challenges with historical accuracy, and building in the same way that people in the Middle Ages would have done. To this end, scientific studies are consulted at regular intervals and scientists are brought into the planning of the castle of Guédelon.

A lord of the castle and a very long construction period

When the initiators of the Guédelon project, set picturesquely in the French commune of Treigny in Burgundy, began their work in 1997, they asked themselves “for whom” they were actually building. They felt that it would make their work easier if they thought of a hypothetical builder who lived at a certain time in the Middle Ages and had a very specific financial budget. This is because both the time of construction and the monetary possibilities shaped the design and appearance of all the medieval castle complexes that we can still admire today. If a castle owner was immensely rich, his castle inevitably looked different compared to when he had to plan very sparingly. In order to be as historically accurate as possible, the first year of construction was defined as 1229. Each year of “present time” was and is subsequently added – so if we assume that construction is actually finished in 2023, historical completion would have been in 1255.

A short local excursion: The commune of Treigny is located, as already mentioned, in Burgundy, a very vast landscape, located centrally in France, which was an independent region until 2015 (since then, together with Franche-Comté, it forms the region Bourgogne-Franche-Comté). From 534, the name “Burgundia” has stood for a Frankish sub-kingdom. At the time of the fictional castle building and until shortly after 1360, the Duchy of Burgundy was ruled by a side line of the French royal house, the Capetians. Treigny, by the way, is a very small village (less than 1,000 inhabitants) and is located along the river Vrille.

The year 1229, which marks the beginning of the construction of the castle, was chosen for two main reasons. At that time, one would have probably tried to authentically imitate the preferred building style of the kings of France at that time. Thus, the architectural design is already predetermined. The political circumstances at the end of the 1220s also make it possible to create a fictional “Lord of Guédelon”, who received a reward from his warlord for his military exploits, which enabled him to build the castle.

Among other things, this fictional construction provides information about which building materials could be used. Thus, it is assumed that the Lord of Guédelon would have been able to finance a castle with stones – but since he would not have been a powerful territorial lord, his financial means would probably also have come to an end at some point. The result is that the diligent builders of the present time, while working with good, solid materials, nevertheless plan sparingly and are rather careful with their use of resources.

European exchange – already in the Middle Ages

We know today that there was a lot of exchange between many European regions during the different periods of the Middle Ages, and the planners and builders of Guédelon are consciously following up on this custom today. In Germany, for example, there is the so-called Campus Galli, a monastery building site that has also set itself the goal of building in a historically correct and ecological manner.

A vivid example: for quite some time, the planners of Guédelon could not say exactly whether and how windows were glazed in the Middle Ages. The empty stone window frames seemed both incomplete and completely unsuitable to adequately withstand the cold seasons in Europe. A scientific study finally provided the answer that at the time of the fictional Lord of Guédelon, it was common to use wooden window frames with parchment skin, which were very practical to handle and usually traveled with the lord of the castle when he was away from home. Since the experts at Campus Galli already had more experience in creating these parchment skin windows, the Guédelon team met them on site to exchange ideas and learn about the specifications and installation. One of the useful pieces of information shared: A special processing of the thin parchment skin can succeed in modifying the otherwise opaque material so that it eventually becomes more and more transparent, helped by the right tension in the wooden frame. Unlike in Campus Galli, however, in Guédelon it is planned to additionally paint the parchment skin windows, which is undertaken by a specially hired artist who uses only historically correct colors. In this way, the wheel of mutual exchange of experience and ideas keeps turning.

An accommodation very close to Guédelon

Incidentally, you will find on our website an accommodation so close to Guédelon that you will easily be able to visit this fascinating construction site before the castle is completed. Our family-friendly tree house in the Loire Valley is located in the middle of nature, not far from the castle of St. Fargeau, where the historical event “son et lumières” (“sound and light”) takes place regularly. The tree house was built sustainably by your host Erik, with natural, untreated wood and is also extremely well insulated. Dry toilets have been installed to allow for the greatest possible closeness to nature, and instead of electric lighting, candlelight illuminates the lodge.


As the most comprehensive source of this article, we would like to refer you to the fantastic ARTE documentary entitled “Building Castles in the 21st Century” (Unfortunately, only in German and French, but it's of course possible to use YouTube subtitles). In this 90-minute documentary, you will learn everything you need to know about the project in Guédelon as well as about comparable projects, such as the Campus Galli. Have fun discovering and diving into a fascinating time that goes back more than 700 years.