The Seven Points of Architectural Restoration
The principles of Architectural Restoration
There are five principles that every professional applies in an architectural restoration project:
Recognizability: each added part must be recognizable from the original to avoid a wrong reading of the work.
Reversibility: any restoration work must be able to be removed without damaging the original.
Compatibility: the materials used must therefore have the same chemical-physical-mechanical properties so as not to damage the original materials.
Minimum intervention: in order to respect the original work, the restoration intervention must be limited to the minimum necessary.
Interdisciplinarity: for a good job it is necessary that those involved in the restoration work actively with professionals from other disciplines such as the historian and the chemist.
Types of Restoration
In the first half of the twentieth century Gustavo Giovannoni, architect and engineer, spoke for the first time of the need for interdisciplinarity and proposed to distinguish between different types of restoration, that is, between restoration of:
consolidation, consists of a series of interventions that restore static safety
recomposition or anastylosis, or recompose the elements of a fragmentary monument
liberation, that is to remove the additions that are considered of little historical-artistic value.
completion, when new parts need to be added that are distinguishable from the original
innovation, involves the addition of new parts to allow the reuse of the object or building.
Intervention techniques: untwist and sew
When the elements to be restored are not simply decorative, such as the friezes of a church, but structural, it is useful to apply the technique of "scuci e cuci" , which consists in replacing the damaged elements and allows to restore the continuity of the masonry and the safety of the structure.
Before starting the intervention it is necessary to perform a photogrammetric survey and a careful diagnostic analysis of the causes that led to the damage to the masonry. Then you have to organize the order in which the interventions will take place, make sure that there are no weights on the masonry and that the part of the wall that will not be touched is firm and fixed.
The wall is supported on both sides and the damaged part is replaced with a wall that has the same chemical-physical-mechanical characteristics.
Four work phases alternate on each damaged part of the wall:
peel off the wall and clean the edges of the affected area. The area on which to act is identified, bearing in mind the distribution of tensions in the masonry itself.
the masonry is disassembled, taking care not to break or damage the adjacent parts and to leave a contour for the subsequent clamping between the existing part and the new part.
the surfaces of both sides are cleaned by wetting them to facilitate the adhesion of the mortar
the mortar and the new parts of the wall are laid.
Characterized by the concept of restoration in the Code of Cultural Heritage and Landscape
The Code of Cultural Heritage and Landscape defines restoration in these terms, in art. 29, paragraph 4:
“By restoration we mean the direct intervention on the asset through a complex of operations aimed at the material integrity and recovery of the asset itself, at the protection and transmission of its cultural values. In the case of real estate located in areas declared to be at risk of seismic according to current legislation, the restoration includes the intervention of structural improvement. "
The legislative text refers to a long and refined path of theoretical definition of restoration, with regard to the two essential aspects, the problem of the conservation of the original material ("material integrity") and the problem of the conservation and transmission of cultural values. Restoration is not only entrusted with the function of preserving the image and the visual aspect, but also of conserving and transmitting the technical and cultural information encoded in the cultural property object of intervention.
Current trends in Restoration practice
In relation to the attitude adopted with respect to the conservation of the original material, the theoretical orientations that are, today, at the basis of the practice of restoration in Italy (see G. Carbonara, Approximation to restoration, Naples 1997) converge in three trends :
- critical restoration,
- restoration restoration,
- purely conservative restoration.
It is a methodological approach to restoration formulated by Cesare Brandi, art historian and director, for a long time, of the Central Institute of Restoration (today the Higher Institute for Restoration and Conservation).
The critical restoration proposes the restoration project as a “reading” of the monument, to be preserved in its historical stratification, between image and matter, in the form in which it has come down to us.
This is the approach that comes closest to what is defined in the legislation, since the intervention tends to preserve the maximum amount of information contained in the asset, while making a choice to identify the values.
Restoration restoration is a theoretical approach that takes up some currents of thought of the nineteenth century (such as stylistic restoration). At a very schematic level, it could be said that it promotes the completion of some missing parts of a monument, or the transformation of some elements, in order to reconstitute an ideal form of the monument, which existed (or supposed to have existed) in the past.
One of the limits of this current of thought is the arbitrariness of the design choices: often the iconographic sources used are relative and imprecise. At another interpretative level, it could be said that this approach is an attempt to abolish the time elapsed and the evolution of the work.
Pure conservation Restoration
The purely conservative restoration (among the exponents of this trend are Mario Dezzi Bardeschi, Stella Casiello) requires the rigorous conservation of the artefact in the completeness of its stratifications and the preservation of the patina, as a sign of the transformation of the material over time.
In any case, the motivated removal of some additions that spoil the visual aspect of the monument is considered legitimate, an aspect that brings this conceptual line closer to critical restoration.
Critical Restoration - Lines of Thought
Schematically, some lines of Cesare Brandi's thought can be outlined:
- the restoration must operate with unitary principles, from the smallest artifacts to the architectural scale;
- the work of art is to be analyzed as a stratification of interventions, which critical conscience must consider in their aesthetic value and in their historical value: it follows that old age itself is not an absolute criterion of value, but judgment it must also consider the aesthetic value;
- the restoration - which is a moment of becoming aware of the work of art - cannot be operated in direct continuity with the past, but must be an interpretation, a critical judgment capable of offering a reading. It follows that a restoration is not a return in time to a past age of the work, but an intervention that must make the work legible, in its successive “stratifications”. The return to an "ideal form", or the return to the "original form", are restoration concepts that characterize stylistic and scientific restoration; these doctrines dominated thought at the turn of the nineteenth and twentieth centuries, but they are now obsolete;
- the idea of keeping the work as it has come down to us implies that the removal of additions must be an exception, not a rule;
- the image of the work is closely linked to the substance (it is an "epiphany of matter"); considered this, the conservation of the image must be substantially linked to the conservation of the material: it follows that the remaking in the same forms with new materials, or the demolition followed by the remaking in identical forms, is not restoration;
- the sign of the passage of time, the patina, is a component part of the work of art; as far as possible, it should be preserved as a sign that characterizes the image.
The conservation of an asset - which presupposes the transmission to the future of the information encoded therein - also implies the conservation, to the greatest extent possible, of the original construction system and structural concept, of the original static schemes, of the original ways of discharging tensions.
The restoration project knows no recipes, but the situation must be assessed on a case-by-case basis. It is the method itself that suggests guidelines for good practice, such as:
- the removal of additions must be considered an exception and not a rule, and will be proposed only if they are intrusive in the aesthetics of the work or harmful from a static point of view;
- generally no to the practice of returning to an original form, which must be assessed on a case-by-case basis;
- it should not be considered a priori - in the case of an architectural artefact - that the value is given only by antiquity, that all the more recent parts are necessarily worthless;
- the original material must be fully preserved (historical plasters, wooden floors, fixtures, stairs, wrought iron railings, original frames, stone elements, even if degraded, etc.), avoiding as much as possible demolition and reconstruction, even with the same material ;
- the completion of a gap with elements shaped according to the original shape is a procedure that enters the practice of repairs; but the full replacement of original, degraded elements with new ones, which reproduce the original form (for example to the frames and frames of windows, shelves, etc.) is a practice that goes beyond restoration;
- you should avoid breaking through bearing walls for new openings, because this practice can cause serious imbalances in the flow of stresses in the masonry and in the overall distribution of stiffness (For the seismic improvement of monumental buildings, see the Guidelines for the assessment and reduction of seismic risk of cultural heritage issued by MIBAC;
- it is good practice to avoid opening traces in the walls to insert pipes and wiring; the traces in the masonry can drastically decrease the load-bearing section of the wall on long segments, causing the structure to lose balance.
Selected Bibliographic References
Cesare Brandi, Theory of restoration, Rome 1963
Giovanni Carbonara, Approach to restoration, Naples 1997
Paolo Marconi, Matter and Meaning - The question of architectural restoration, Rome - Bari 1999
Giovanni Urbani, Around the restoration, curated by B. Zanardi, Milan 2000
Stella Casiello, The culture of restoration. Theories and founders, Naples 2005