Keywords

1 Historic Urban Landscape (HUL) and Sustainable Urban Development

The World Heritage List stands as a testament to the collective endeavor of humanity to preserve the treasures of the past for future generations. Among the diverse array of sites inscribed on the list, approximately one-third of the properties are comprised of historic cities and historic urban areas. This finding underscores the cultural significance of urban landscapes, their profound impact on the narrative of human history, and in shaping the collective memory of humanity. From the ancient metropolises of Mesopotamia to the medieval cityscapes of Europe and the vibrant bazaars of the Orient, these historic sites exemplify a profound sense of place, identity, and continuity that resonates with people from diverse cultural backgrounds.

As urbanization continues to sculpt the global landscape, the safeguarding of these living historical entities becomes an imperative task. Challenges that historic urban areas face today arise from the intricate interplay of factors such as rapid urbanization, population growth, the tensions between globalization and local development, evolving social dynamics, and pressing environmental concerns (Bandarin and Oers 2012). These contemporary challenges add layers of complexity atop the enduring historical tension between urban development and conservation, which calls for an integrated approach that transcends conventional conservation paradigms (Rodwell 2010). It is within this context that the concept of the Historic Urban Landscape (HUL) assumes paramount importance, heralding a new paradigm in urban development that harmoniously integrates heritage values with urban change.

The modern vision of urban conservation, characterized by its holistic approach to urban heritage, marks the culmination of a complex intellectual evolution originating from the specialized field of monuments conservation. While the formal discussion around the Historic Urban Landscape (HUL) approach was initiated by the UNESCO World Heritage Committee in 2003, with the Vienna Memorandum of 2005 (UNESCO World Heritage Centre 2005) further shaping its formulation, the early inklings of recognizing the holistic significance of urban heritage can be found in the conservation and management tradition developed in the late nineteenth century, which gained a renewed relevance in the aftermath of the modernist urban transformations.

In this pivotal era, pioneering thinkers such as Riegl (1982) and Sitte (1965) laid the conceptual groundwork for conceiving urban heritage as an interconnected whole. Riegl’s theory of values sought to interpret the conservation of monuments through the lens of their inherent cultural and historical worth, propelling a shift away from a purely materialistic approach. Concurrently, Sitte’s groundbreaking perspective on the city as a historical continuum highlighted the need to derive guiding models for the development of the modern city from its historical evolution. It is indeed in this phase that foundational concepts that later found resonance in modern charters and the HUL approach began to take shape.

As the twentieth century unfolded, the advent of modernism and the rapid pace of urbanization precipitated the erasure of historical layers, threatening cultural identities that had shaped cities for centuries. In response to the fervent drive for rapid modernization, the concepts of memory value, esthetic enjoyment, and collective responsibility for conservation gained renewed significance as essential counterbalances. This stark clash between the conservative vision of preserving historical urban fabric and the relentless pursuit of modernization laid bare a fundamental question: how do we reconcile the imperatives of conservation and development? Can a middle ground be found between the ‘rigid’ conservation of the historic city and its complete removal and replacement? The nuanced opposition engendered by this query continued to fuel theoretical developments throughout the twentieth century, with the ideas of renowned urbanists, such as Jacobs (1961), Mumford (1938), and Lynch (1960) seeking a harmonious integration of conservation and development within the urban context. Within this intellectual crucible, the seeds of the HUL approach were sown, proposing a visionary paradigm that navigates the intricate terrain between heritage preservation and urban change.

The definition given in the recommendation on the HUL (UNESCO 2011) gives a thorough understanding of the holistic vision of heritage represented by the HUL idea and highlights some of its most important conceptual developments: broader understanding of urban space, moving beyond urban conservation as a specialized practice and its “operational” potential worldwide.

“The historic urban landscape is the urban area understood as the result of a historic layering of cultural and natural values and attributes, extending beyond the notion of ‘historic centre’ or ‘ensemble’ to include the broader urban context and its geographical setting. This wider context includes notably the site’s topography, geomorphology, hydrology and natural features, its built environment, both historic and contemporary, its infrastructures above and below ground, its open spaces and gardens, its land use patterns and spatial organization, perceptions and visual relationships, as well as all other elements of the urban structure. It also includes social and cultural practices and values, economic processes and the intangible dimensions of heritage as related to diversity and identity.”

This definition lays the foundation for a comprehensive and integrated approach to the identification, assessment, preservation, and management of the historic urban landscape within the broader framework of sustainable development. The fact that an international legal instrument operates with such expansive and profound concepts is remarkable and aptly reflects a paradigm shift from traditional conservation frameworks that prioritize individual structures, towards an all-encompassing appreciation of the urban landscape as a whole. If compared to the vision set in the 1964 Venice charter (ICOMOS 1964), a founding document on urban conservation that considers historic city as a setting for historic monuments rather than a heritage system, it can clearly be seen how long way the international understanding of urban space, historical city, and its present value have gone over the past half a century. More than that, the groundbreaking conceptual framework of HUL positions it as an attitude as to how cities develop, a “mindset”, as it was defined by the Expert Meeting on HULs held at the UNESCO Headquarters in November 2008.

Understanding HUL as an attitude rather than a heritage category is especially important as it allows the international community to arrange for the semantic and conceptual differences that inevitably underlie any process as complicated as articulating a set of universal guiding principles for historic city management. Understood in these terms, the HUL approach sets itself as a global shared attitude towards the key concepts mobilized in the historic city conservation and management practices, which represents another groundbreaking development overlooked by the first international documents (Cameron 2008).

Another important aspect of HUL is that the concept marks a significant drift away from the confines of urban conservation as a specialized practice. Rather than considering conservation in isolation, HUL reimagines the preservation process within the expansive framework of urban management and development. This link between the two—a crucial step to the integrated approach to sustainable management of a “living” historic city—is traceable in two milestone documents of the second part of the twentieth century, namely the Declaration of Amsterdam (ICOMOS 1975) and the European Charter of the Architectural Heritage (Council of Europe 1975). Both of them place the conservation as an objective of city planning and put an emphasis on the necessity of considering areas of historic interest rather than historic buildings alone. Elaborating the idea, the 1976 Recommendation concerning the Safeguarding and Contemporary Role of Historic Areas (UNESCO 1976) also associates development to conservation, expanding its scope from urban areas to the outside of the city. Furthermore, the need to “preserve the traditional social fabric and functions of the historic areas” cited in the document as one of the goals of conservation is a clear indication of the management concern in the international conservation discourse.

These developments, later crystallized in the HUL concept, make the conservation informed by a concern for the future as much as for the past. Within the context of HUL, in fact, the term "historic" transcends its conventional association solely with age, transforming into a concept imbued with particular meanings and intrinsic values (Jokilehto 2010). This evolution not only underscores the dynamism of urban landscapes but also emphasizes their relevance to contemporary societies. Establishing a past–present continuity that beams the heritage up from its historical setting to the city as it appears today, HUL advances beyond the confines of the specialized conservation field, embracing a broader narrative that integrates heritage into the continuum of urban life, encouraging sustainable development while nurturing the authenticity and distinctiveness of cities.

2 The Florentine Experience: Adopting the HUL Methodology as Part of Urban Development Toolkit

The value-based understanding of the historic city provided by the HUL is today widely seen as the basis for a methodology used to govern the territory in an integrated and holistic manner. The 2011 Recommendation defines the concept of HUL as a structured methodology encompassing six “phases” and applicable through four “tools” to holistically and integrally manage the territory. By linking the Outstanding Universal Value—the key concept underlying the recommendation—to the relationship between the historic fabric and its surroundings, as well as to the functions acquired by the city over time, HUL provides guidance and direction for urban conservation, development and management of historic cities and their surrounding areas.

The experience of the Historic Center of Florence that will be discussed further serves as a case study of how research, additional levels of protection, and international recommendations can be incorporated and implemented within existing municipal regulations. This institutional linking of historic centers with the surrounding landscape is a practice that can be applied to various urban contexts, including sites not listed on the World Heritage List.

Due to its strategic location between the Arno River and the hill system, Florence has preserved over the centuries its naturalistic character, wherein the traditional agricultural landscape remains discernible, adorned with rural houses, historic villas, and religious structures. The context in which the historic center is located highly contributes to the value of the World Heritage site, with its integration with the surrounding landscape being cited as a condition of integrity in the statement of Outstanding Universal Value of the Historic Centre of Florence. Thus, through the implementation of the HUL methodology, the Municipality of Florence intended to work on a balanced conservation of the fragile landscape  surrounding the city center to guarantee the integrity of the World Heritage site.

The 2011 Recommendation on the Historic Urban Landscape of Unesco reads: “present and future challenges require the definition and implementation of a new generation of public policies identifying and protecting the historic layering and balance of cultural and natural values in urban environments.” With this in view, the Florence World Heritage and Relations with UNESCO Office of the Municipality of Florence has implemented a series of actions to adopt HUL as a guiding operational category in its site management model, including strategic projects, the definition of the buffer zone and enhancement of the governance model.

The journey towards the HUL methodology implementation began with the project “Firenze dal centro alle colline: Belvedere e percorsi panoramici” conceived in 2011–2012 (Bini et al. 2015a). This study, carried out by the Florence World Heritage and Relations with UNESCO Office in collaboration with the Department of Architecture of the University of Florence, was aimed at guiding urban transformations of the Historic Center of Florence in a way to ensure the integrity and enhancement of the city’s image. The study resulted in the identification of 50 panoramic points with corresponding visual axes that contribute to the identity of the Historic Center, particularly in terms of preserving the integrity of the city’s skyline.

The subsequent research for defining the Buffer Zone of the site (Bini et al. 2015b) was based on elaborating the data from the aforementioned study and the overlay of different protection levels (areas with landscape restrictions, protected buildings, archeological interest areas, parks, areas of particular green value, minor historic centers, rivers, etc.). The identified buffer zone is a 10,480 hectares area surrounding the World Heritage site, developed to provide an additional layer of protection of the immediate backdrop, principal vistas, and other structural and functional characteristics of the site.

In the case of Florence, the acknowledgment of the World Heritage site’s buffer zone both by UNESCOFootnote 1 and the local planning mechanismsFootnote 2 marked the incorporation of the HUL concept into the main instruments of local territorial planning and regulation. This significant step not only contributed to safeguarding the integrity of the landscape and the skyline of the historic center but also contributed to the enhancement of the “ecological corridors” which are useful in countering urban sprawl in peripheral areas (Francini 2022; Francini 2017; Francini and Montacchini 2021).

Consistent with the aim of tangibly enhancing the relationship between the historic center and the hill system, the proposal to extend the perimeter of the World Heritage site was developed. This proposal, approved during the 44th extended session of the World Heritage Committee in Fuzhou, China, in July 2021, aimed to rectify a formal representation error in the site’s map that had excluded the San Miniato al Monte complex, explicitly mentioned in the 1982 Statement of Outstanding Universal Value. The site boundary revision presented an opportunity to include not only the missing attribute but also an area characterized by gardens, avenues, and ramp systems—a veritable urban park designed for enjoying the city’s greenery and panorama, connecting the historic center to the hill ecosystem.

Another “tool” that facilitated the implementation of HUL principles in the context of the Historic Centre of Florence is related to the revision of the governance and efficiency check systems. As through the “landscape” lens HUL immediately suggests the necessity for cross-sectoral action, the Municipality involved the Steering Committee in the system of governance of the site. The committee consists of stakeholders on the local, municipal, and regional levels,Footnote 3 thus incorporating the concept of landscape management in operational terms and enhancing the efficiency of the HUL implementation mechanism. Meeting twice a year, the committee is a valuable opportunity for the stakeholders to align the common goals and the vision that transcends the competencies of a single authority, similar to the way in which the idea of the Outstanding Universal Value of the site transcends the boundaries of the formally understood historic center.

The steering committee’s primary responsibility is to oversee the update and implementation of the Management Plan. This classic instrument of urban governance is another opportunity for the effective implementation of the principles of the HUL. During the updating of this 2022 Management Plan (Municipality of Florence 2022), the HUL approach was used as one of the programmatic documents for determining the macro areas and projects selected within the action plan.

For what concerns the enhancement of the monitoring system, significant changes within the World Heritage site and its Buffer Zones are monitored through Heritage Impact Assessment (HIA), another implementation tool related to the HUL approach (Chiesi et al. 2020). This methodology builds on existing Environmental Impact Assessments (EIA) and Strategic Environmental Assessments (SEA) employed to mitigate the potential negative impacts of development on the OUV of a World Heritage site. HIA is a non-binding instrument that offers guidelines for assessing the impacts of changes on heritage values. In the Florentine context, a tailored HIA model developed for the historic center is incorporated into the 2022 municipal Operational Plan. This model serves both at political and technical levels to guide interventions, particularly those involving infrastructure projects and the repurposing of disused areas within the World Heritage site and its buffer zone.

In the past years, the World Heritage Center organized a series of events under the auspices of the World Heritage Cities Programme to celebrate the 10th Anniversary of the 2011 UNESCO Recommendation on the Historic Urban Landscape.Footnote 4 Bringing together the site managers of the UNESCO World Heritage cities, these events served as a catalyst for the wider adoption of the HUL approach.

The Florence World Heritage and Relations with UNESCO Office of the Municipality of Florence participated in several initiatives organized by the World Heritage Cities Programme of the World Heritage Centre (WHC 2020), including those related to the celebrations of the 10th anniversary of the HUL, thus contributing to the dissemination of the strategies implemented in Florence and the exchange of good practices. A Call for Action (WHC 2011) was issued on this occasion—to which the City of Florence also adhered—to raise awareness of the authorities and communities and to accelerate the incorporation of the approach at the bureaucratic level.

3 Conclusion

The discussed model for site management—by retaining values in a changing environment—is a unique example of HUL implementation in Italy that has an immense potential for rethinking the World Heritage sites management principles worldwide.

For historic cities, the UNESCO Recommendation on the HUL stands as an invaluable asset due to its dual role as both a comprehensive theoretical framework and a practical operational tool for urban management and conservation. However, the international community is still in the early stages of the exploration into the depths of the historic urban landscape’s significance. According to the latest report on the implementation of the 2011 Recommendation (WHC 2023), 36% of member states have integrated the conservation of cultural heritage with urban development plans, policies, and processes using the HUL framework. Given that the concept of the HUL isn’t solely applicable to historic centers designated as World Heritage sites, but rather extends its relevance to all historic centers, it's evident that there’s still a considerable journey ahead.

With the internalization of debate on urban conservation, the need to reconcile conservation and development, a daunting challenge per se, was further complicated by the ambition of establishing standard-setting instruments for heritage conservation as the response to the challenges that affect historic centers worldwide. In this regard, the concept of the HUL stands as an exceptional example of a universally applicable methodology. Unlike some conventional approaches that risk homogenizing cultural aspects when applied beyond their original context, this approach, as recognized by Bandarin (2012), embraces local value systems as a pivotal factor in urban heritage conservation. By doing so, it transcends the confines of inflexible legal frameworks and propels itself into a realm of adaptable, context-sensitive methodologies that resonate with the diversity of urban landscapes worldwide.

The universality of the HUL approach holds another crucial aspect—its adaptability to existing legal systems. This is especially important for making the HUL methodology operational in contexts with rich national or local framework of management principles and conservation methodologies.

In recent years, the international community has assisted in the significant process of recognizing the value of World Heritage that has constituted an important opportunity for reevaluating management policies and programmatic tools within local administrations. Looking ahead, the international community’s goal is to offer tangible solutions to the intricate challenges faced by historic cities. In this endeavor, a comprehensive understanding of the intricate interplay between heritage values, urban dynamics, and sustainable development serves as a versatile guide for policymakers, and urban and heritage practitioners worldwide.