The materials used on the Guédelon construction site mainly come from the area itself. The ferruginous sandstone is extracted directly on-site, which provided approximately 7,500 tons of stone during the first six years of activity at the construction site. The limestone used in a more confidential way for certain works of art in the castle is directly imported from Donzy in the Nièvre department. The 150 tons per year of Guédelon mortar with its characteristic color are a mixture of fat lime from the Allier department with sand, water, and earth directly taken from the site.