For this reason, some arcades were built against the external walls of the church and later destroyed.
The façade, in white limestone, presents a bell gable, rebuilt in the 16th century with two overlapping mullioned windows. Below them was the central rose window destroyed by the earthquake of 1832 and reconstructed in 1883. There are two mullioned windows on the sides of the rose window. Three portals (the side ones are closed) gave access to central nave and side aisles divided on the inside by pillars on the left and by columns on the right.
The original truss ceiling was replaced in the 14th century by three deep arches made of masonry; progressively lowering, they give the illusion of a more depth to the central aisle. The altar is made up of a pillar and a lid of a Roman sarcophagus. The semicircular apse and the central nave are decorated with frescoes of Umbrian school of the 15th century.
In 1393 the whole presbyterial area was painted by the Orvieto artist Cola di Petruccioli, and we can still admire St. Andrew Apostle, a Virgin and Child and the Archangel Gabriel, St. Rufino and St. Lawrence. In the central aisle a fresco attributable to Giovanni di Corraduccio (15th century), the Virgin and Child, St.Anthony Abbot and St. James.