摘要
We prioritize interventions in the roof structure in order to prevent subsequent deterioration of the monument. This presentation refers to interventions in two Spanish National Monuments: the Collegiate Church of Roa de Duero and San Esteban's church of Los Balbases. The Collegiate Church was built during the 16th century. It is considered the jewel of the villa. It is a "hallenkirche" model with three big naves of the same height covered by beautiful starry vaults. The intervention consisted of restoring the wooden roof structure, preserving the original 16th centary structure, by replacing the damaged elements. It was restored according to archaeological criteria. San Esteban's church is a 13 century Gothic style church with a Latin cross plan. It has three naves with a transept of great slenderness. It preserves Romanesque remains. Opposite to the previous intervention we decided to rebuild the roof because the former roof was totally distorted due to bad executed works during the past Century. In this way we regain the original shape of the church. These interventions aim to improve constructive and structural conditions as well as retrieve the image of both monuments. We have studied the visual impact of interventions through virtual recreations. The intervention criteria are very different, restoration versus structttral reconstruction.