On the lateral façade a staircase-lift has been built, connecting the basement and subsequent floors. The supporting c.a. structure is coated, both internally and externally, in local stone of various sizes and arranged in horizontal bands with four randomly alternated heights. Occasionally on the façade it appears a sign, an incision, a fossil, a manifestation of what the museum holds. The image that appears is that of a container which itself becomes an object to be exposed. A museum whose function is already clear from its outer casing.

The added body is backward and lower in height than the existing building. On the stone coated monolith, cuts are made on the façade to ensure the best views of the most important landscape points, the nineteenth century city on the side prospectus and  the district of "Carmine" on the rear prospectus. The cuts have the same slope of the roof, which alternates the slope of the gable on both prospects.