After the massive use of ferruginous sandstone for the foundations and bearing walls of the castle of Guédelon, limestone was used for the dwelling of the lord, his aula, and his bedroom. This milky white rock had already been used for the ribbed intersection and the spiral staircase of the chapel tower. The construction of the great hall of honor of the castle was an opportunity for the stonemasons to give the full measure of their talent and to build beautiful works of art such as, in particular, five twin windows with tympanums decorated with trilobes or four lobes, door frames, or fireplaces.