Birth and affirmation of the principle of "minimal intervention" in the practice of restoration in the United Kingdom (19th c.)

This paper traces the history of nineteenth-century restoration in the UK by high-lighting the events, theories and documents that will lead for the first time in Eu-rope at the maturation of the restoration discipline. The world of architecture and the possibility of a physical survival of monuments found a professional and ethi-cal dimension that can be considered sustainable in many subjects. The confusing and arbitrary stylistic restoration, with all its contradictions and unruly, is recog-nized as a deleterious practice to the conservation of ancient buildings. Some architects addressing the restoration to the stylistic unity became the target of a growing collective movement that challenged the scraping and demolition, and upholds the principle of “minimal intervention” by John Ruskin. Just the ideas of the writer and philosopher and his suggestions for the restoration of monuments will generate a need for clear rules. The negative evaluations expressed by many critics, historians, politicians and scientists demonstrate that interventions were not sustainable from many points of view: procedural (absence of a methodological approach), technical (destructiveness), economic (high costs for drastic measures), and social (no respect for the authenticity and deception of style). The Papers on the Conservation of Ancient Monuments and Remains (1865) will be adopted to contain the vast controversy generated by the outcome of the stylistic restoration. The document contains the guidelines approved by the Royal Institute of British Architects, designed with the innovative conservative approach; it must be pointed out that some of the most current meanings attributed to the term “sus-tainability” are perceptible in its articles. The essay will demonstrate how the principle of “minimum intervention”, the re-spect for the historical stratigraphy, and the fundamental interdisciplinary contribu-tion of chemical science had already become the characteristics of “sustainable” restoration in the UK in the nineteenth century.