A programme of experimental archaeology carried out since 2002 on the archaeological site of the “château d’Orville” at Louvres (Val d’Oise) has enabled us to attempt, among other things, the reconstruction of certain Carolingian buildings. A hut and a granary supported by posts have both been the subject of two different versions in the light of recent research into roof structures and roofing practices in the Middle Ages (rafters forming a truss, shingles).