Bad or Good? Proposal Towards a Quality Evaluation for Interventions on Built Heritage

1. Common value and responsibility

The concept of the built heritage seen as common value, implying also common responsibility for ensuring its preservation in full authenticity, was rightfully the one which opened the statements of the Venice Charter in 1964. This core principle is the only one directly related to all the others, and that qualifies it to be on the top of the list. I will only comment upon the most significant relations it has with the other principles (and implicitly, evaluation criteria).

While the principle of authenticity will be briefly presented below (see point 2), it is important to note its intertwined relation with the one of common value and responsibility. If the authenticity is preserved, so is the value, hence the responsibility is honoured; if one fails to preserve authenticity, it means that also failed in their responsibility to preserve the heritage of many others, before and after them. Likewise, the responsibility is fully honoured only if the authenticity is also preserved; however, neglect can also be considered as a failure of the direct responsibility to preserve, thus passing the responsibility entirely to the future generations. In any case, neglect can’t generally be considered for evaluating an intervention, except when the time proof criteria can be applied (briefly discussed above).

Although covering all the other criteria in a broader sense, to avoid double evaluation, only specific items can be considered for this section, such as the direct involvement of the community or of the authorities, or the relation between the ones responsible for the intervention and the beneficiary community – all in the perspective of good sustainability.

2. Authenticity

This is by far the most important criterion of all, for which a dedicated charter was adopted [22] and significant documentation and literature published [11,23]. Regarding restoration, the Venice Charter states that “Its aim is to preserve and reveal the aesthetic and historic value of the monument and is based on respect for original material and authentic documents.” (m.e., Art. 9 – similar with Art. 3, referring also to conservation). Furthermore, “Replacements of missing parts must integrate harmoniously with the whole, but at the same time must be distinguishable from the original so that restoration does not falsify the artistic or historic evidence.” (Art. 12); this statement also feeds to the principle/criterion of interpretation (see point 8).

Regarding archaeological excavations, the resulted “Ruins must be maintained and measures necessary for the permanent conservation and protection of architectural features and of objects discovered must be taken. (...) All reconstruction work should however be ruled out «a priori». Only anastylosis, that is to say, the reassembling of existing but dismembered parts can be permitted.” (Art. 15)

3. Consistent documentation

“The conservation and restoration of monuments must have recourse to all the sciences and techniques which can contribute to the study and safeguarding of the architectural heritage.” (Definitions, Art. 2). More or less the same words put in another arrangement indicate a valid reciprocal: the study and safeguarding of the built heritage are integral parts (or phases) of the conservation and restoration process(es); they are supposed to be recurrent, or rather permanent processes, just like conservation. Art. 9 confirms it: “The restoration in any case must be preceded and followed by an archaeological and historical study of the monument.” (m.e.). Another relevant reference to documentation is in Art. 16: “In all works of preservation, restoration or excavation, there should always be precise documentation in the form of analytical and critical reports, illustrated with drawings and photographs. Every stage of the work of clearing, consolidation, rearrangement and integration, as well as technical and formal features identified during the course of the work, should be included.”

The documentation is also complementary to authenticity. In the discussed context, the two main qualities of built heritage are: its physical features, which may contain aesthetical, and/or technological values that can only be experienced directly in its actual presence (which is why it is so important); and the associated information, which consists of data (about size, shape, material(s), consistency, location, vicinity and spatial relations etc.), and metadata (evidence regarding absolute or relative chronology and utilization range; indirect evidence of usage etc.) – the latter frequently mediated by interpretation. Hence, whenever it is decided that physical features are to be removed, it should be mandatory for the removal to occur after documenting it as rigorous as possible; in fact, the documentation should also be considered as a necessary substantiation for the removal itself, accompanied by explanatory notes.

4. Diversity

Article 1 states, within the core definition of the historical monument / built heritage, that the former refers “not only [to] the single architectural work but also [to] the urban or rural setting”, and “not only to great works of art but also to more modest works of the past” (m.e.). While the chronological references to the past or the passing of time (also in Art. 1) are quite relative, and arguably left to be more precisely established by each country, “within the framework of its own culture and traditions”, the references to a generous interpretation of scale (ranging from object, ensemble, to urban scale) and environment (both urban, and rural – or rather territorial, for isolated buildings or ensembles) are clear and seem to have a proper coverage. However, the term “modest” requires some attention in this context.

Arguably, “modest” opens towards a wide range, similarly with the previously discussed spatial and environment criteria, in fact covering their wider scales in a great proportion. According to Collins Dictionary, “A modest house or other building is not large or expensive.” [24] This brings us to the concept of minor architecture, coined almost a century ago [25], which is valuable especially as an ensemble (e.g. an urban or rural ensemble of historical houses), but not only (e.g. a few houses left from a former ensemble, or an isolated historical manor in a rural or isolated area).

Overall, diversity seems to be an appropriate concept to integrate the aspects mentioned above. I would only add that it should also be applied to the quality assessment of the built heritage, not only to the intervention itself. For example, the early 20th century phases of an older (medieval, or ancient) ensemble or site could also be considered a valuable part of it, may it be a modest addition compared with the previous phases. Hence, if stripping monuments of their more recent evolution phases is indeed considered now a disagreeable practice, the same should apply to ensembles and sites: “The valid contributions of all periods to the building of a monument must be respected, since unity of style is not the aim of a restoration. When a building includes the superimposed work of different periods, the revealing of the underlying state can only be justified in exceptional circumstances and when what is removed is of little interest and the material which is brought to light is of great historical, archaeological or aesthetic value, and its state of preservation good enough to justify the action.” (Art. 11)

5. Appropriate use

The “appropriate use” is a wording taken from by Jukka Jokilehto [21] (Art. 5) to briefly describe what the Venice Charter states in Article 5:

“The conservation of monuments is always facilitated by making use of them for some socially useful purpose. Such use is therefore desirable but it must not change the lay-out or decoration of the building. It is within these limits only that modifications demanded by a change of function should be envisaged and may be permitted.”

(m.e.)

Although the current (or present) relevance of the use is very important (primarily for the sustainability of the intervention), it is conditioned by its adequacy to the existing built heritage. It must be stressed, therefore, that it is not the desired function that dictates the use of the monument, but rather the monument dictates (through specialists’ evaluation and intervention plan) on how it can be adapted to fit new functions.

6. Context preservation

This principle applies mostly to large(r) scale intervention policies; therefore it has a significant ethical component, besides the (conclusive) interventional one:

“The conservation of a monument implies preserving a setting which is not out of scale. Wherever the traditional setting exists, it must be kept. No new construction, demolition or modification which would alter the relations of mass and colour must be allowed.”

(Art. 6)

The evaluation criteria derived from this principle may, or may not be relevant for an intervention, depending on its scale and type – however, when it is relevant it is also critical [21] (Art. 6). It is important to note that frequently there are different actors responsible for the larger scale interventions, therefore it is important to asses a fair accountability in this regard.

The relocation of built heritage can also be inscribed to this principle and, subsequently, to the corresponding criteria:

“A monument is inseparable from the history to which it bears witness and from the setting in which it occurs. The moving of all or part of a monument cannot be allowed except where the safeguarding of that monument demands it or where it is justified by national or international interest of paramount importance.”

(Art. 7)

Moreover, “Additions cannot be allowed except in so far as they do not detract from the interesting parts of the building, its traditional setting, the balance of its composition and its relation with its surroundings.” (Art. 13); the part referring to historic sites, seen as “sites of monuments”, hints largely on the same ideas (Art. 14).

7. Expertise

This matter is surely delicate, but also necessary to be further addressed more than it did in the Venice Charter: “The process of restoration is a highly specialized operation.” (Art. 9) Presumably, most countries require certain degrees of expertise for the evaluation of and intervention on built heritage, however limitations can occur on many registries. For example, a specialist may have a generic expertise for intervention design on built heritage, but has never worked with, nor ever studied late roman fortifications. (This type of heritage is very particular, for it is rare and frequently preserved as ruins, see the case study below.) Is any such specialist qualified to operate on such a monument? Legally, it could be the case; ethically, not quite, unless his expertise is supplemented by that of a specialist who understands the monument, and this knowledge is actually integrated in the intervention project.

Expertise also refers to the quality of the implementation (thus, of the intervention itself), which sometimes is even more difficult to assess unless properly explained and documented. Beyond this metadata of an intervention, the visible architectural implementation and the details of execution are perhaps the easiest aspects to evaluate.

8. Interpretation

This concept became doctrinal in the late 2000s, with the ICOMOS Charter for interpretation [26]. However, its roots are clearly traceable in the Venice Charter. The baseline for respecting this principle is, firstly, honouring the authenticity (see point 2). Regarding restoration, the charter states that “It must stop at the point where conjecture begins, and in this case moreover any extra work which is indispensable must be distinct from the architectural composition and must bear a contemporary stamp.” (Art. 9). For archaeological structures, while maintaining the ruined state (see point 2), “every means must be taken to facilitate the understanding of the monument and to reveal it without ever distorting its meaning. (...) The material used for [anastylosis] integration should always be recognizable, and its use should be the least that will ensure the conservation of a monument and the reinstatement of its form.” (Art. 15)

One could argue that interpretation is not a vital criterion for preserving a monument in its full authenticity, depending on each situation. For example, an archaeological ruin could be preserved without efforts to understand its architectural configuration. Nevertheless, if one counts larger ethical principles, such as common value and responsibility, where sustainability plays an important role, it turns out that the interpretative part of the intervention is perhaps the second most important, after preserving authenticity. This is the pragmatic perspective, while the scientific approach would vote instead on the consistent documentation. However, a good interpretation can only be obtained through a proper documentation, therefore the ideal chain results to be authenticity, documentation, and interpretation.

9. Structural compatibility

This criterion is indirectly implied by several of the Venice Charter articles (see Art. 3, 4, 9), but perhaps the most relevant is the one stating that:

“Where traditional techniques prove inadequate, the consolidation of a monument can be achieved by the use of any modern technique for conservation and construction, the efficacy of which has been shown by scientific data and proved by experience.”

(Art. 10)

The structural capacity of the built heritage is obviously an essential element of authenticity, thus it needs to be preserved. Still, it is perhaps one of the most common problems and fragile topics in the common practice, because it interferes with present building regulation and norms, which are not always compatible with the parameters of historic buildings [15]. This situation is taken to extreme in some cases, based on the argument that structural safety prevails any other feature of the built heritage, thus requiring either incompatible materials and techniques, either exacerbated measures, or even both. The case study in this paper is an example for the latter.

10. Reversibility and minimal intervention

Although none of these terms are specified as such in the Venice Charter, reversibility and minimal intervention are implied, albeit subliminal, by many of its statements (Art. 3, 4, 5, 6, 7, 8) [10]. Perhaps the closest to the concept of minimal intervention, albeit not quite straightforward, is the following part from Article 11:

“When a building includes the superimposed work of different periods, the revealing of the underlying state can only be justified in exceptional circumstances and when what is removed is of little interest and the material which is brought to light is of great historical, archaeological or aesthetic value, and its state of preservation good enough to justify the action.”

Regarding reversibility, it may be the considerably more relevant for archaeological structures than for others, but surely not exclusively; in the former case, the material used for [anastylosis] integration “should be the least that will ensure the conservation of a monument and the reinstatement of its form.” (Art. 15)

It is fairly recognized that there is no such thing as 100% reversible intervention, therefore the purpose of this principle is to highlight on the “as much as possible” key – i.e., finding the best compromise in correlation to all the other principles, for the best interest of the built heritage. I considered it to be complementary to the minimal intervention (required) in the sense that these two principles are in fact directly proportional. Following them with priority would normally rather serve the heritage, than the other way around. The more reversible an intervention is, the more it is accountable as minimal intervention, and vice versa, the more an intervention is kept to a necessary minimum, the more reversibility is less of an issue – even if, as always, counterexamples can be found.

11. Publication

Referring to the complex documentation of the built heritage and of the corresponding interventions (see point 3), the last of the articles in the Venice Charter concludes that “This [documentation] record should be placed in the archives of a public institution and made available to research workers. It is recommended that the report should be published.” (Art. 15) Updating this idea to our days, in a transparent approach to cultural heritage, may mean that ideally the documentation could be made available online. Nevertheless, although this rough documentation would be of great value, two other types of publication would surely be very welcome for the interested public: a synthetic publication of the authors and a specialized review.

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There are a few intrinsic principles of the proposed evaluation system, that I believe to be essential for both its applicability and sustainability:

• Simplicity: it has to be as simple and intuitive as possible, so that people outside the field could easily understand it; this principle stands for the accessibility of information and the transparency of the evaluation process, in respect for the larger public – seen as the main beneficiary of the built heritage and of all the efforts to preserve it;
• Flexibility: everything about its structure and components should be possible to adapt or even change, when necessary or opportune, based on proper argumentation: criteria, their interpretation, sub-components, percentages etc. While some core categories of these parameters should be controlled by designated specialists (e.g., criteria and interpretation), others could be customized by the various users (e.g. criteria applicability, percentages, or at least some larger intervals). Likewise, anyone should be free to use it for practice and testing hers or his own perception;
• Objectivity and diversity: the official evaluations, approved by relevant authorities in the field, should be anonymous specialists in the field (on the famous Michelin Guide model); however, non-anonymous second opinions should be allowed on behalf of other specialists, while popularity rating could also contribute to a general perception and understanding of the intervention. Notably, significant disparities between specialists, or specialists and public, should raise some questions useful for the correlated education in the field;
• Accessibility: the necessary data, the evaluation instruments and the results should be available online and free of charge.

Perhaps more important principles could be identified, and many more suggestions may be formulated for their optimal implementation, but for the preliminary level proposed here it could suffice.

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For most of the subjects, only dedicated and detailed research could support a comprehensive understanding of the discussed structures in their historical phases, so that each intervention, and especially the most recent ones could be evaluated as objectively as possible, relative to their historical context. Thus, for the demonstrative purpose of this paper, I have chosen what could be labelled an “easy target” – for two reasons. Firstly, that the recent intervention upon it is quite obviously a bad one, despite the scarcity of available data documenting it – except for the abundance of photographs available online, published largely by the visiting public. Secondly, for I am already familiar with its history and configuration, as it was one of my PhD case studies for Late Antique urban centres [27].