Restoration policy for each project in this period was basically set up by preservationists at the Ministry of Education through historic investigation on original state of buildings. Chief preservationist at the Ministry, Ryonoshin Sakatani and his successor Minoru Ooka, tried to re-create original design as the concept of architectural preservation, restoring roof shape (often changed by posterior repairings) as a decisive aesthetical element to the overall architectural form. Their positivist academic research-not only on original buildings' form but on unexplained ancient carpenter's technique to make curved roof lines(Kikujutsu)-seemingly gave their idea a certain legitimacy. This architecture-oriented concept, opposed to historian's, was crystallized in Ooka's idea for the Horyuji Toin Denpodo restoration(1938-43) where nonetheless hostile objections its original roof was thoroughly reconstructed on account of preserving techniques of the Nara period such as the manner of projecting eave rafters(Hiendaruki).
