Guédelon's mission had been clearly defined: a search for the highest degree of authenticity in all the work practices used on site, the only limit being current health and safety legislation.

an open-air laboratory

One of the treadwheel winches in the castle courtyard © Guédelon Ph. D. Gliksman

The day-to-day organisation of a 13th-century building site remains, to this day, difficult to interpret.  Indeed, the importance of the Guédelon project is its ability to both put to the test tools and ways of working, whilst also proposing credible solutions for problems as they arise - for example, the chemical composition of mortar.

This leads us to continually consider the different options available, in all aspects of the construction, with the aim of putting into practice the theory which can be most logically applied in each field; therefore, it was important to put in place a methodology.

The methodology adopted for making architectural choices

One long-term aim is to compile an extensive bank of information and keep it updated. This data bank is the result of collecting data from three principal sources: - contemporary iconography, such as illuminated manuscripts and stained-glass windows, and medieval building contracts (only a few surviving fragments).

letting the stones speak

Druyes-les-Belles-Fontaines castle, 25 km from Guédelon

- field trips and surveys in situ at castles from the same period and based on the same architectural canons. Some examples being the castles of Druyes-les-Belles-Fontaines (89), Ratilly (89), Yèvre-le-Châtel (45) and Dourdan (91).

- modern scientific sources: symposium reports, theses, archaeological excavation records etc.

By processing this information, we create the most complete index of data possible, which can then be referred to when selecting the most appropriate architectural options for Guédelon castle.

There is also another source of information which we couldn't have imagined in the project's early days and which is particularly gratifying: our visitors. Many, during, or after their visit, have shared with us their knowledge of such-and-such a technique, or the presence of an architectural feature near their home.

This is central to the dialogue which we envisaged at the start of our venture!

The cross-rib vault on the Chapel Tower's ground floor - © Guédelon - Ph. Guédelon

The example of the cross-rib vault on the ground floor of the Chapel Tower:

One of the potential pitfalls was for Guédelon to become a mere catalogue of architectural feats. Guédelon must not become a vehicle for celebrating the achievements or satisfying the tastes of a few. Building the biggest, the most elaborate, the most sophisticated possible vault to the detriment of stylistic, architectural and chronological consistency would have been inappropriate and nonsensical.

Our method is therefore to build the features most generally represented in castles of this period. With this aim in mind, a team from Guédelon has visited our different reference castles, notably Yèvre-le-Châtel (Loiret) and Dourdan (Essonne) to take photos, make sketches and draw the layouts.

This preliminary work makes it possible to draw up precise, coherent working plans which are then presented to the advisory scientific committee for approval.

live from Guédelon