These tracery windows are of gothic style, in line with the building period of Guedelon castle, during 13th century.
The sketches and drawings are provided by the master builder, validated by the lord of the castle (our direction, nowadays), starting points to launch the work.
We start by splitting entire oak trunks, to obtain planks that are squared and leveled with an ax and a side-ax. These rough boards are planed and shaved with a scrub-plane(a plane with a rounded blade) and a jack plane (a long-size plane). They are then assembled into a flat large wood plank, thanks to assembly grooves that were carved using wood chisels.
The drawing of the tympanum is reproduced on the wood plank, then sawed with the manual scroll saw, mounted on a wooden frame. Each cut piece is rasped to a smooth finishing and the moldings are gouged.
The window frames are decorated with sculpted capitals. Models are prepared with clay, then casted with plaster and reproduced into wood by working with gouges. The capitals are formed with hooks (folded leaves of acantha) and oak leaves.
All pieces being ready, they are assembled with wooden pegs and tightened together.
In middle Age, the glass industry had basically disappeared and glass windows or stained glasses were very expensive, so their use limited to most prestigious and religious constructions. A castle like Guédelon could not afford it and its windows were closed with alternatives to glass, namely fabrics or parchment.
In Guédelon, linen tissues were chosen and the painters paint and wax the window linens which will later be nailed or sewn to the finished window frames.
A large field of research was developed to understand the assembly and fixing methods, the decorations of the glasses-less windows, the treatments of fabrics or parchment with oil or wax. These are not documented in retrieved texts and can only be suggested and inferred from Medieval drawings, paintings and illuminations.
The final mounting of the window to the building is planed for the year 2025.