Consolidating Stone Architectural Heritage: A Spatio-Temporal Analysis of Restoration Practices at the Pitti Palace in Florence

In recent times, composite materials have been increasingly used in the conservation of historic structures. Among these, Fibre-Reinforced Polymers (FRP) have emerged as a viable alternative for reinforcing stone facades. The widespread adoption of this deep consolidation technique is primarily due to its versatility, high strength-to-weight ratio, and its effectiveness in addressing issues such as corrosion and differential thermal expansion, which were commonly associated with earlier metal-based anchoring techniques. The paper examines the application of composite materials in reinforcing the stone facades of the Pitti Palace in Florence, Italy. The palace has been selected as a paradigmatic Florentine case to describe the ongoing conservation efforts aimed at preserving the building’s ancient materials, while at the same time ensuring the safe use of this architecture by people. After a brief description of the construction site and trans-formations of the monument, the paper analyses the characteristics of Pietraforte, its geological history, and the inherent properties that make it prone to detachment and the falling of stone fragments. The consolidation works carried out on the palace’s stone facades, spanning from the late nineteenth century to the present, are reviewed, with a focus on the materials and techniques employed – ranging from copper banding and metal pins (copper, brass, and iron) to stainless steel rods and, more recently, FRP rods. The study offers a spatio-temporal analysis of over a century of restoration practices and provides an initial assessment of their impact and effectiveness. The preliminary findings contribute to the broader discourse on heritage conservation and long-term management, with a particular emphasis on controlling the progressive deterioration of stone facades, which in this case are under the stewardship of the Uffizi Galleries.