On the side opposite the central hall, beyond an antechamber that guides visitors through the building, lie two symmetrical rooms: one dedicated to research and the other to the display of materials. Although primarily functional spaces, they were designed with meticulous architectural and decorative care, fully reflecting the Library's representative character.

Finished in light neutral tones, the walls provide a backdrop to an elegant decorative scheme whose richest expression appears in the coffered ceilings.

These ceilings are organised as a regular grid of rectangular panels framed by shaped beams and stucco or moulded plaster joists. Decorated with scrollwork, oval motifs, interlacing ribbons and foliage, the raised frames imitate more precious materials such as carved wood or stone through the careful use of paint and chiaroscuro.

Within the panels, the decorative motifs are clearly inspired by the Neo-Renaissance style. Leaf rosettes, acanthus scrolls, palmettes, scrolling cartouches and symmetrical compositions are drawn directly from the decorative vocabulary of the Italian Renaissance. Classical grotesque decoration is reinterpreted in a more measured and orderly manner: lines are simplified and compositions are carefully balanced to suit a public institutional setting.

The Renaissance influence is also evident in the emphasis on harmony and proportion. Each decorative element forms part of a carefully ordered system in which symmetry and repetition establish a strong sense of visual balance. At the same time, some details—such as more animated volute motifs and richer vegetal ornament—reveal a subtle Neo-Baroque influence, though in a light and controlled manner.

The decoration is executed primarily in tempera on plaster, with additional moulded stucco providing greater relief to the frames and to the wall medallions depicting the Muses, inspirational figures of the arts. The colour palette favours delicate and harmonious tones—beige, cream, taupe and ash grey—enhanced by subtle shading that lends depth without overpowering the space.