Challenges for Sustainable Urban Heritage Conservation in the Twenty-First Century: The French Perspective

Abstract

Over the past decades, the interest in urban sustainability has grown internationally through the implementation of a multitude of policies, initiatives, and tools. This growth is primarily due to the intensity of climate change, intensification of pollution, and rapidly increasing urbanization, among other factors. In this worldwide context, heritage conservation tools have often proved to be inadequate in handling contemporary challenges. The conservation community has called for a renewed approach to better integrate heritage management strategies within the larger goals of overall sustainable development. However, the convergence of heritage conservation and sustainability agendas is not evident despite the fact that the role of heritage in sustainable development is becoming unquestionable. To date, several publications on this topic tend to focus mostly on theoretical discourse. There is practically no general consensus in terms of how to update heritage conservation policies and tools to take the imperatives of sustainability into account. To address this gap, the current paper aims to discuss the need to implement a holistic and integrated approach to urban conservation by presenting the French case study. Indeed, since the beginning of the 2000s, France has revised its consolidated regulatory framework for the safeguarding of urban heritage to open up to sustainability targets. Recognizing sustainability as a primary challenge facing urban conservation, the paper is divided into three parts. Firstly, a comprehensive overview of the state of the art in the field of urban heritage conservation and sustainable development is provided. Secondly, the French context is presented, focusing on the influence of national environment and sustainability legislation on urban conservation tools. Lastly, the emblematic case study of Paris is investigated. The research finds that an integrated approach appears to be necessary, both at theoretical and operative levels, and some first-stage answers have been provided in this direction.

1 The Conservation of the Historic City at Issue

The current profound environmental crisis, as well as social and economic crises, caused by development models recognized as unsustainable, has brought studying the processes underlying urban sustainability to the center of an international debate about the future of cities (Joss, 2015). Urban centers are the focal points of this unprecedented crisis, having been affected by major changes and pressures that render it urgent to adopt policies and tools to ensure sustainable development models. Attention to this issue is so great that sustainability has come to be considered the major issue of the twenty-first century (Barthel-Bouchier, 2016; Wagner, 2011). In historic urban contexts, the unprecedented scale of this crisis is even clearer and presents a risk to protecting their related heritage and identity values (Bandarin & Van Oers, 2012; Leifeste & Stiefel, 2018). Exponential urbanization, climate change, insufficient resources, social imbalance, and pressure from tourism are all factors that appear to threaten the material and immaterial integrity of cities’ urban heritage.

While makes it urgent to have operational strategies to achieve sustainable development objectives, it also leads to questioning the validity of current urban conservation policies and tools, considering the emergence of these new challenges. For these reasons, the need is often expressed to rethink current approaches to conservation, in the international literature, in the broader framework of sustainable development (Appendino, 2017) The main agencies in charge of protecting and enhancing heritage have also expressed the importance of an integrated approach to sustainability to address these challenges (UNESCO, 2011).

At first consideration, this seems to raise no problems. The concept of sustainable development does appear consistent with that of heritage conservation, as both have the same intent of incorporating different time periods, placing past, present, and future in a system of transmission and intergenerational solidarity (Garat et al., 2005) and offering humans harmonious living conditions in the environment we live in Rodwell (2007). Furthermore, heritage is a non-renewable resource itself, to be protected and enhanced on par with natural resources, which makes it a lever for sustainable development (ICOMOS, 2011). Nonetheless, despite the consensus on a theoretical level that heritage and sustainable development are inseparable and indispensable for the historic city's future (Civilise, 2012), there still seems to be general difficulty in incorporating sustainability principles and objectives in heritage conservation policies and measures (Albert, 2015). Although the concept of sustainable development has become central on a global scale in the urban agenda, the realm of heritage conservation has only recently started to consider the broader implications of its requirements for heritage conservation principles and guidelines (Cameron & Inanloo Dailoo, 2011). In practice, many experiences have shown a degree of difficulty both in finding the balance between these two imperatives as well as clarifying their relationship to each other and establishing how to implement this integrated approach (Albert, 2015).

This research originated, in this sense, from the intent to explore how principles, policies, and conservation tools for urban heritage could be integrated with sustainability objectives with the intention to add a piece to the larger debate, involving the academic world as well as institutional and professional ones. The aim of this article specifically is to discuss how these issues are addressed in France, where not only is there a particularly extensive debate on the matter but also several attempts to address the issue have been made. While on one hand, sustainability objectives are at the top of the agenda and have taken on growing importance in urban policies, on the other, attention to protecting urban heritage is very strong, and increasing areas of the cities are subject to protection through a variety of tools and policies. Considering the case study of the Secteur Sauvegardé of the VII Arrondissement of Paris lets us underscore some limitations of these attempts as well as identify good practices for revising the approach to urban heritage conservation.

2 Methodology and Research Objectives

This paper, which incorporates some results from my doctoral research,¹ is based on the starting assumption that in the current moment of great change and unprecedented pressures, the sustainability agenda sets new goals for policies to protect urban heritage and offers an opportunity to evolve the tools it uses. Sustainable development has not in fact been considered a priority in urban heritage conservation, at least until now. This article aims first to understand how the issues tied to sustainable development are situated in the context of the historic city and that of urban heritage conservation, and then, through a pragmatic approach, to reconstruct the field of action within which to encounter policies and tools of sustainability and conservation. We chose to study some innovative approaches by looking at the French context and a case study of Paris, which made it possible to explore operational tools, test them in the field, and have direct contact with those involved.

The objective of the research's first stage was to identify the issue within the current debate and focus on studying the current state of affairs and more specifically theoretical aspects, for which a thorough study of the international literature was needed. This stage also involved the critical analysis of institutional international and European documents. After studying the current situation and epistemological thinking, the second stage concerned choosing the French context. This stage lets us assess how the issues previously identified were addressed in this context, therefore focusing on French-language literature in order to understand the French version of these issues and the current debate. The third stage then focused on the local context by analyzing the city of Paris and the revision of the Secteur Sauvegardé management plan for the VII Arrondissement.

For the purposes of our study, these two stages of our research used sources of varying types, including planning documents at different regional scales, official documents, and legislative texts, as well as reports and documents for the general public, which proved important to our analysis. This body of material was studied in parallel to field work with interviews conducted with about 20 key players, including researchers, planners, officials, specialists, and representatives of local and national authorities.

3 New Challenges for the Historic Cities: An Opportunity to Rethink Urban Heritage Conservation

The literature on urban conservation describes how the concept of urban heritage has undergone a progressive, gradual expansion over the years, both at the semantic level and the land planning level, which has led it not only to include intangible aspects, social factors, and cultural values (Dormaels, 2012) but also to accept constant development and change as intrinsic conditions (Duché, 2010; Fairclough, 2003; Giliberto, 2018; Labadi & Logan, 2015). This gives a view into a process already underway toward a new paradigm of protecting the historic city (Van Oers, 2010) as shown by the orientation of the current debate on protecting the concept of the “historic urban landscape,” which, in effect, sanctions expanding the field of attention from individual properties to historic areas, the existing city in all its manifestations, and the historic territory in its cultural entirety (Gambino, 2013).

Nonetheless, though the rather static conception of urban conservation of the first part of the twentieth century has gradually given way to this more dynamic one, a study of the literature seems to suggest that the conservation discipline has not been able to keep pace (Bandarin & Van Oers, 2015). This takes on particular importance and urgency in the context of the new challenges to which historic cities are now subjected (UNESCO, 2009), which require sustainability. This goal was largely ignored in the previous century and now has become the primary rule of thumb for protecting urban heritage in order for historic cities to continue to be important in the global era (Bandarin & Van Oers, 2012).

This is why in the last decade, the main international organizations operating in the field of heritage have opened a discussion on the principles of conservation (Giliberto, 2018), thereby reflecting the development of a debate already underway in countries like France, Italy, and England. In the late 1990s, some scholars already started to question the adequacy of conservation measures and asked if “modern conservation should not be redefined in reference to the environmental sustainability of social and economic development within the overall cultural and ecological situation on earth” (Jokilehto, 1999). The problem of sustainable development has also started to affect the realm of conservation (Wagner, 2011), which has seen the need to align historic urban areas with sustainability objectives, i.e., the need for a management process that can ensure the continuity and historicity of the urban fabric (UNESCO, 2005). This idea later culminated in the 2011 Recommendation on Historic Urban Landscape, which reflects the need for a “rethinking of urban conservation” to make for more sustainable urban management and development processes through innovative tools based on policies and practices sensitive to ecology and equipped to integrate economic, social, cultural, and environmental concerns (UNESCO, 2011). The major challenge that arises is being able to implement a holistic approach that can integrate the conservation of heritage and sustainable urban development in all its realms, which seems far from a common practice today (Guzman et al., 2014). This shifts the attention from the mere consideration of heritage as a resource to be protected to the contribution it can have in finding solutions for current urban problems (Labadi & Logan, 2015).

This is clearly a challenge for the conservation field, which until recently had never “presented its work in a way that links it strongly to issues of sustainability” (Teutonico & Matero, 2003), but it is also an occasion (Appendino, 2017) for a profound reconsideration of principles that now seem dated and inefficient (Fernandez et al., 2014). A review of the literature does indeed show that “very little attention has been paid to the question of how sustainability may influence and alter heritage conservation practices” (Cameron & Inanloo Dailoo, 2011). However, in order to earn “a place at the table of sustainability” (Wagner, 2011), the conservation discipline must understand that this could mean more than rethinking its fundamental principles and would entail dialogue and engagement with other disciplines (Bandarin & Van Oers, 2015). This is the only way that heritage conservation can “move forward in ways that permit the survival of memory, tradition, and a multiplicity of values, and that acknowledge limited resources and the fragility of our ecosystem while promoting manageable change, sustainable development, and improved quality of life” (Teutonico & Matero, 2003). Heritage conservation should, therefore, be integrated into the planning of general urban development policies, offering mechanisms to reconcile conservation and development, within the broader objective of sustainability (Bandarin & Van Oers, 2015). In order to address the challenges facing it, urban conservation cannot, therefore, be seen as some sort of nostalgic and elitist activity, but as a central aspect of sustainable development (Teutonico & Matero, 2003), giving up the illusion of “a walled precinct protected from the external forces of changes by plans and regulations” (Bandarin & Van Oers, 2012).

4 Urban Heritage Conservation and Sustainability: Divergences and Convergences

The intensity and speed of current changes are a major challenge to urban heritage conservation and make it essential that it be aligned with the sustainable development goals. There seems, therefore, to be a consensus about the need for a new approach to conservation policies and measures that are often considered no longer sufficient and adequate (Bandarin & Van Oers, 2012, 2015; López Sánchez et al., 2020). However, while at the theoretical level, this appears to pose no problems (Nocca, 2017), at the operational level, it does raise some conflicts (Albert, 2015; Appendino, 2017; Carabelli et al., 2011; De Vita, 2012), which makes it interesting to investigate the relationship between conservation and sustainability.

A number of authors argue that these two concepts are close to one another, given that heritage is a non-renewable resource to be protected and passed on to future generations (Nijkamp & Riganti, 2008), as well as a major component of quality of life (Tweed and Sutherland, 2007) and enmeshed with issues of memory, identity, and aspiration (Auclair & Fairclough, 2015), all of which are central to the discourse on urban sustainability (CIVVIH, 2010). Other authors insist that the historic city is already sustainable and should be taken as a model (Rodwell, 2010). They note that it has key elements of the sustainable city, including compactness and density, which make it possible to reduce car travel and promote cycling and pedestrian mobility (Gehl, 2010); functional and social mixité, indispensable elements for a vibrant city (Fernandez et al., 2014); resource conservation and adaptive reuse (Plevoets & Van Cleempoel, 2019), an energy-efficient urban form (Salat, 2011). More generally, “conservation has always been about sustainability: […] about finding a way to have the past inform the present and future without compromising the need to improve and to assure a certain quality of life” (Teutonico & Matero, 2003).

Despite these parallels, several scholars have shown that there is only an apparent convergence between conservation concerns and sustainable development goals (Emelianoff, 2005) so that the two concepts are therefore often juxtaposed without being truly linked (Garat et al., 2005). For instance, there is the principle of urban renewal and densification, which while central to the discourse on urban sustainability (Jacquand, 2005), are in contradiction to the aim of protecting and making heritage last (Emelianoff, 2005; Garat et al., 2005). Another factor of contradiction involves the energy requalification of historic buildings (Mazzarella, 2015), as well as the difficulty of adding energy production systems from alternative resources (Webb, 2017), as well as adapting to new technologies and current living comfort performance levels (Wise et al., 2021). This is why reservations have been expressed about the “ecological tolerance of heritage” (Planchet, 2009) because heritage conservation implies, at least in theory, the principle of “touching as little as possible,” and current regulations on the issue greatly limit the adaptability of these historic buildings. It is, therefore, legitimate to ask to what extent, effectively, it is possible to make this heritage compatible with the energy-environmental needs of sustainable development (Ter Minassiah, 2011).

Beyond environmental sustainability, some authors have noted how heritage conservation and enhancement policies have a major impact on cities’ social fabric, frequently leading to original businesses being pushed out and the resident population being gentrified. While it is true that heritage must be “made to last” according to the principles of sustainable development, it is equally true that heritage must be “made to live” (Gravari Barbas, 2005). This also involves functional mixité, which is very much challenged by tourism pressures that tend to undermine the identity values of heritage, turning historic areas into commercial opportunities for a transient population (Bandarin & Van Oers, 2015).

Another element of conflict is the trouble that the urban conservation sector has in managing change as an element intrinsic (Fairclough, 2003) to the very definition of the historic urban landscape. Some scholars consider this to be one of the most important obstacles to the development of urban conservation (Van Oers, 2010). It takes on central importance in the current debate around the verticalization process (Appert, 2008) happening in many historic cities, which threatens complex historic stratification and its distinctive characteristics and values, in the name not only of modernization and progress (Labadi & Logan, 2015) but of sustainability as well (Appendino, 2017). Replacing historic urban fabric with new energy-efficient, technological, and often vertical buildings is indeed often promoted by the local authorities in the name of density, reduction of land consumption, more efficient mobility, and lower carbon emissions. There seems to be, once again, a considerable gap between theoretical and operational principles: the traditional “innovation/conservation” dialectic (Cassatella et al., 2007) which appears to have been overcome on a theoretical level by recognizing that there can be no authentic conservation of values without continuous innovation (Gambino, 1999), in practice, it appears a still open question that has trouble defining the admissible limits for change (Appendino et al., 2016).

5 Toward the Sustainable Development of Urban Heritage Conservation in France

France has responded to the intensification of environmental issues and international awareness of the need to ensure that urban development is as sustainable as possible with an important legislative review process, which has seen urban planning evolve towards the establishment of sustainability objectives (Prévost et al., 2012). The turning point can be considered the 2007 Grenelle de l’Environnement,² the start of a series of political objectives which introduced truly comprehensive reform of sustainable urban planning (Dubois-Maury, 2010). More recently, laws on the 2015 Energy Transition, the 2019 Energie-Climate, and 2021 Climate et Resilience have set ambitious objectives for environmental sustainability with a particular focus on the built environment.

Significantly, sustainability legislation has also had an important impact on the tools used to protect urban heritage (Versaci, 2016); all measures are now required not only to tackle sustainable development objectives set for a given area but also actively contribute to their achievement (Appendino, 2017). This is also the case for the Secteurs Sauvegardés,³ the highest, most restrictive level of urban conservation, long considered an urgent measure based on the city's museum-like status (Choay, 1992), now asked to integrate with the urban sustainability policy (Planchet, 2012). In some cases, this has even led to a complete rethinking of some measures, which could call an “ecologization” (de Lajartre, 2012) of urban heritage management measures. This applies to Aires de mise en valeur de l’architecture et du patrimoine⁴ (AVAP), introduced by the Loi Grenelle II of 2009 to replace the Zones de conservation du patrimoine architectural, urbain et paysager (ZPPAUP)⁵ introduced in 1993 to meet the sustainability objectives. Leaving aside concerns about safeguarding heritage, other issues such as energy efficiency and renewable energy play a key role in the measure.

This is an important innovation in that, up until now, protected areas could be likened to enclaves with respect to the rest of the region, in terms of both regulations and objectives. The French urban heritage conservation system is one of the most well-established models in Europe and is highly complex (Molinié-Andlauer and Appendino, 2021). The conservation policies have evolved in parallel to the evolution of the concept of heritage (Gigot, 2012) and this led to a proliferation of conservation measures, whose structure often seems complex (Morand-Deviller, 2002). For example, there are many means of conservation on an urban scale: Sites inscrites ou classés,⁶ Abords des Monuments historiques,⁷ Secteurs Sauvegardés, ZPPAUP, AVAP, often leading to an overlap of conservation perimeters and complexity in structuring the rules and players involved. This is a full-fledged legal arsenal established to protect the urban heritage with an overwhelming number of possible measures (Leniaud, 2007; Vecco, 2009).

With a view to the “simplification, acceleration and modernization” of the conservation system, the new heritage law, Loi CAP, was adopted in 2016 and met with a negative reception from many experts who took a critical, dubious attitude to the proposed changes. The main change contained in the new law is unquestionably that introduce Sites Patrimoniaux Remarquables (SPR),⁸ which stems from merging the Secteurs Sauvegardés, ZPPAUP and AVAP into a single integrated urban measure. These sites may be managed according to a PSMV,⁹ an urban planning document that replaces the PLU, or a PVAP,¹⁰ a public utility easement annexed to the urban planning land-use plan. Other significant changes concern the mandatory introduction of UNESCO heritage into planning documents, the possibility of revising the size of the perimeters in agreement with the superintendency, recognizing the heritage value of contemporary architecture by using a specific label and streamlining some procedures to expedite and simplify obtaining authorization to carry out works. It is worth noting no other major change has been made in the name of sustainable development, although the context of climate urgency underlying the new law is emphasized immediately.

6 Need for an Integrated Approach in the Case of the Secteur Sauvegardé of the VII Arrondissement in Paris

In this context, the Paris case is emblematic to examine the structure of the conservation and sustainability policies from an operational perspective. Paris is a leader in Europe in policies and initiatives promoting urban sustainability (Laurian, 2012), and due to its exceptional urban heritage, almost its entire area is under at least one conservation measure. Such a situation could have led to a ban on all innovation and development, but the city, unable to expand its boundaries, but densely packed with buildings, population, and activity, has always tried to evolve and change within itself (APUR, 1983). Nevertheless, some studies, focused on the building scale have demonstrated that heritage is often marginal in environmental sustainability policies, emphasizing the lack of thinking that references conservation policies as well (Ter Minassian, 2011).

The current challenge facing Paris is to find a balance between sustainable development and heritage conservation. Among the many urban heritage conservation measures concerning the Parisian region, the case of the Secteur Sauvegardé of the VII Arrondissement (now a Site Patrimonial Remarquable) is interesting as it seems to demonstrate that in practice this challenge is still ongoing. As mentioned, the Secteur Sauvegardé measure is historically the highest level of urban heritage conservation, and its provisions are contained in the PMSV. This is an urban planning document structured to reflect the urban land-use plan, which it replaces within the conservation perimeter. However, it differs from the latter in the level of detail contained in its provisions and the control exercised by the superintendency (Architecte des bâtiments de France). The Secteurs Sauvegardés were created for an urban area with an exceptional urban heritage, such to require ad hoc urban management tools. This is why the plan provides specific and detailed provisions for each individual built component or open space (Appendino, 2018). In the case of the Secteur Sauvegardé of the VII Arrondissement in Paris, a revision of its PSMV was needed to integrate the conservation sector into the more general framework of the sustainable development policy adopted by the city. The objectives were set for the entire urban territory and, as a result, for the perimeter included in the conservation measure as well, which, as such, needed to find a balance between conservation and sustainability.

The conservation sector in question started in the seventeenth century around the abbey of Saint Germain des Prés and the religious institutions that first covered the land around the abbey. Following the fall of the Ancien Régime and the dismantling of most religious orders, it became the bureaucracy district, which to this day is the site of a large number of ministries and embassies which effectively ensured the heritage's high state of conservation. In architectural terms, the sector is marked by the presence of several hôtel particulier, built starting in the eighteenth century. This makes the urban fabric of the secteur sauvegardé more fragile, not particularly dense and sparsely populated compared to the city’s average, which in the 1960s was especially vulnerable to real estate development. Consequently, there was a need for an “urgent measure” to safeguard the historic urban fabric unique to France (APUR, 1983), resulting in the adoption of the conservation sector in 1972. However, it was not until another 20 years later that it had a PSMV, a highly detailed policy that requires considerable financial resources as well as lengthy procedures and adoption times.

Given these timeframes, it is fair to say that when the PSMV was approved in 1991 it was already “dated” in a sense as many urban, economic, social, and cultural changes had taken place over the 20 years it took to complete it (APUR, 2004). By the early 2000s, there was, therefore, already a clear need to revise the plan in effect which, despite having ensured the conservation of heritage, appeared to be “too conservative” (Ville de Paris, 2016) to let the sector participate in new urban dynamics. In particular, there was a need to bring the content of the plan in accord with the sustainable development objectives set for the entire Paris area. While on the one hand, the Secteur Sauvgardé is excluded¹¹ from the Plan Local d’Urbanisme (PLU),¹² on the other, it is an integral part of the Projet d’Aménagement et de Développement Durable (PADD),¹³ applied to the area as a whole, whose objectives it must support in order to be legally approved. This meant an evolution of the conservation policy, the updated version of which was to make the sustainable urban development objectives central, on par with those related to heritage conservation. The PADD of Paris, adopted in 2006, is a summary document containing the major guidelines for sustainable development of the urban area. The actions and objectives proposed in the document, which the PSMV was asked to engage with, can essentially be traced to a traditional view of sustainable development based on three pillars (environment, society, and economy).

To briefly summarize, the main changes that have taken place in the economic sphere are based on the new plan's underlying intent to preserve the neighborhood's traditional economic businesses, mainly based on craft and retail businesses, now threatened by a rise in real estate prices, and its residential function, threatened by an ever-expanding tertiary sector. From a social perspective, the new plan responds to the PADD’s social mixité objectives, with the goal of achieving 30% social housing by 2030, through several ad hoc provisions. This aspect has turned out to be particularly complex in that the PLU identifies the conservation sector as the area of the city most deficient in terms of social housing (Ville de Paris, 2016), with a social housing rate of around 1%. In particular, some state properties in the sector had to be acquired to achieve this objective; this gave rise to a dispute as there was no agreement in place between the city of Paris and the government on the sale price of these lands, on which social housing was to be built, resulting in a tug-of-war that was only resolved after many years.

Lastly, in terms of environmental sustainability, the new plan must refer not only to the PADD but also to the Climate Plan,¹⁴ which sets a 30% reduction in greenhouse gas emissions by 2020. However, a distinction must be made: if the PSMV has to be compatible with the PADD in order to have legal validity, the Climate Plan need only be “taken into consideration”, which is less binding.¹⁵ This is why, despite the fact that the new plan confirms the energy-saving objective, it also specifies that the provisions of the Climate Plan must be adapted in the PSMV regulations in order to preserve the main objective of protecting and enhancing heritage (Ville de Paris, 2016). The plan’s priority objective would therefore still seem to be heritage conservation, as reiterated several times in the document. The need to reaffirm this aspect is interesting and would seem to imply a specific hierarchy in which sustainable development is relegated to the background. Moreover, nowhere is it specified whether the goal to reduce greenhouse gases by 30% is mandatory, which makes it seem to be a reference point rather than a requirement, as it is for the rest of the urban area. Another two important points on which the plan focuses are the conservation of biodiversity and discouraging the use of private vehicles. In this regard, the plan prohibits building underground parking facilities and limits the creation of on-street parking. However, with regard to biodiversity, it is unclear why there is no mention of the city’s Biodiversity Plan,¹⁶ which is one of the cornerstones of Paris’s environmental policy.

In conclusion, it can be said that the revised plan is still a tool primarily aimed at protecting heritage, though it sets itself the goal of preventing the city's museumization. Sustainable development goals have often been limited or reformulated to better adapt to the sector's needs to the point of sometimes disappearing altogether. As such, the innovative scope of the plan revision that had been originally conceived seems to have been partly reduced due to integrating sustainable development objectives. Overall, the new PSMV, adopted in 2016, does appear substantially revised compared to the previous one as each individual provision is considered in detail. A change of perspective can be discerned from a museum-like view of heritage to a more dynamic one, open to change (Appendino, 2018). Only one element is unchanged, the perimeter of the conservation area. This aspect is unique as the perimeter had been established at a time in history in which there was a need to save historic heritage from the threat of urban renovation. Yet, current conditions have changed greatly and the need conveyed in the revised plan is first and foremost to ensure that broader urban dynamics take part in this heritage while ensuring its conservation. It is therefore striking that the boundary was left unchanged, dividing the Arrondissement into two virtually equal areas, the western one where the PLU applies, and the eastern one where the PSMV applies. Though many buildings have the same architectural features, the buildings on the east side are part of the conservation plan, while those on the west side are not. They are protected by the PLU instead, which is less binding. In the PMSV, environmental sustainability objectives, primarily for building energy efficiency, are to be implemented, whenever possible, dependent on the main objective of conservation, in the area where the PLU is applied, the Climate Plan is applied in compliance with requirements for energy retrofitting (Appendino, 2017) The interviews given show that the decision not to revise the conservation perimeter was implemented by the city of Paris precisely because this tool is still perceived as an obstacle to sustainable urban development.

7 Opening and Resistance of the Conservation Sector: A Nuanced Balance

Studying the French context clearly shows that there has been the intent and attempt to reconcile urban heritage conservation and sustainable development. The example of Paris presents some yet-to-be-resolved elements of conflict. Heritage conservation is asked to find compromises in order to participate in a comprehensive local plan in the difficult context of environmental urgency (Planchet, 2009). The interviews carried out with some institutional actors, researchers, and professionals working in the heritage conservation sector, on a national and local Parisian level, made it clear how difficult it is to find this compromise, which is confirmed by the outcomes. The first questions concerned the concept of sustainable development applied to historic urban contexts, and then they focused on the impact that this has on their practices and professional approaches, and finally on the specific context of Paris and in some cases of the Secteur Sauvegardé studied.

The first basic factor emerging from these interviews as a whole is identifying four recurring points of view: the first, the most frequent, sees sustainable development as a threat to urban heritage conservation; the second perspective sees sustainable development as potentially risky to heritage but also considers it inevitable that they must now engage with each other; the third point of view that emerged sees heritage itself as already sustainable and lasting so that there is no genuine conflict; lastly, the fourth point of view, decidedly less common than the first three, sees sustainable development as an opportunity for heritage conservation, rather than a risk because it aims to achieve a broader balance that is beneficial for the sector. Interestingly, these four approaches mirror the theoretical debate. Table 1 shows these four approaches, along with some key quotes.

Table 1 Four approaches identified in the interviews

A second element that was found to be shared by all the interviewees was the strongly expressed need for a more holistic definition of the concept of sustainable development, currently focused purely on its energy-environmental dimension. Most of the interviewees saw that conflicts arise from an overly restrictive misinterpretation of the concept of sustainability. Another divisive element was the change of the ZPPAUP into AVAP, as set by the Loi Grenelle II. Several interviewees emphasized the reduction of heritage conservation being justified in the name of sustainable development; in effect, not only are the two objectives complementary here but also the role of the superintendency is reduced. In contrast, others supported the shift of this tool as it could reconcile two objectives that have often been seen as in conflict.

The interviews showed that the integration of sustainability objectives within the conservation measures has not met with support, which, from the perspective of some, is still far from being earned. The main criticisms raised specifically concerned the gradual loosening of some conservation provisions to meet the sustainability objectives. Some urban planning tools now make it impossible to prohibit works whose purpose is to improve the energy-environmental performance of buildings, including historic ones, unless they fall within certain conservation perimeters, which are, however, dependent on the same local community. Because the superintendent's opinion is not asked and the procedures for implementing this conservation have not been defined precisely, a great deal of autonomy and decision-making freedom are left to the individual municipalities. These concerns appear more understandable if we consider that almost all of the interviews took place at the same time as the heritage bill and energy transition bill were presented, though their groundbreaking scope has since been reduced in the approved bills. Many exceptions were allowed in the name of sustainable development.

This was the origin of the wariness expressed by most of the interviewees. Though they recognized the need for the historic city to keep on evolving, keeping its heritage from museification, they questioned whether imposing the imperative of sustainability was not effectively just a pretext for urban works that are less respectful of existing heritage. In conclusion, it should be emphasized that this attitude, which might seem one of “closure,” we consider mainly attributable to an absence of dialogue between actors who appear to have different interests. Our interviews showed that the Ministry of Culture and conservation professionals perceive sustainable development as something imposed on them without having the true possibility to share strategies that could instead give a proactive role to heritage conservation.

8 Conclusion

This research sought to bring two concepts into relationship, which, as we have seen are often placed in opposition: sustainable development and heritage conservation, focusing on the urban scale. The current context of crisis and unprecedented pressures that historic cities are under today make it urgent to achieve sustainable development goals in these contexts as well while safeguarding their heritage. While at least at a theoretical level, this assumption appears to be agreed upon, in practice it is still difficult to integrate these two imperatives, which are simultaneously called into action. Though the concept of urban heritage, which is always evolving, has gradually expanded over time, leading it to accept change as an inherent condition, conservation tools do not seem to have kept pace.

This study of the French context confirms this difficulty, which in our hypothesis, had shown harmonization of these two imperatives. Sustainable development has indeed been an opportunity to innovate conservation tools and policies; Protected areas are no longer urban niches focused only on heritage conservation but are now brought to play an active role in urban policies and sustainability of a global scope. However, the interviews conducted and debate arising from the new heritage law have led us to question this. A cross-analysis of the interviews carried out indeed allowed us to understand how the most widespread attitude still sees sustainable development as a potential risk for heritage and an unwelcome imposition. The research shows that this harmonization can generate conflicts, partly because it is often not defined in detail how the sustainability objectives will be integrated. The process of revising the VII Arrondissement PSMV offers many insights on this point. Despite the intent to review conservation measures with a view to sustainable development, the case studies highlight some difficulties and contradictions in the integration and hierarchization of the principles of sustainability and conservation. The most critical issue involves environmental sustainability objectives; the conservation plan's many constraints indeed still make it a very “conservative” tool. The conservation perimeter remaining unchanged, for instance, which seems to confirm an approach to the conservation sector that still sees it as an enclave.

These results seem to suggest that the challenge of sustainability requires a more comprehensive rethinking of current conservation mechanisms, as well as profound innovation in the discipline and its organization on multiple scales. In our opinion, greater dialogue and cooperation are needed between the actors, in order to build a truly joint strategy, as well as updated tools that are suited to managing and supporting this harmonization and an expansion of the concept of sustainable development. As we have emphasized several times, this is not limited only to the environmental aspects. Despite the specificities of the case discussed, the results show that, on an operational level, managing change in historic urban settings is still an open problem and an urgent one, now more than ever. While in the literature, it is now widely recognized and agreed upon that the safeguarding of historic heritage means first engaging it in the contemporary realm and that the future of heritage cannot consist of policies of absolute prohibitions and restrictions, it must nevertheless be recognized that the case studied presents uncertain, disputable outcomes, reflecting the yet-to-be-resolved dialectic between the contemporary reality and the memory of places.