The Multidimensional Evaluation of Cultural Heritage Regeneration Projects: A Proposal for Integrating Level(s) Tool—The Case Study of Villa Vannucchi in San Giorgio a Cremano (Italy)

Abstract

The challenges of sustainable development are mainly concentrated in the cities. Therefore, they represent a key place for implementing strategies and actions to achieve (or not achieve) sustainable development objectives. In this perspective, the circular city model represents a new way of organizing the city. As demonstrated by a variety of best practices, the entry points for triggering circular processes at the urban scale are various. In this paper, cultural heritage is presented as the entry point for the implementation of this new urban development model. The focus here is on the implementation tools, with a particular emphasis on the evaluation tools for assessing the effectiveness and efficiency of this model, that is, the multidimensional benefits that it can produce. The Level(s) tool, proposed by the European Commission in 2017, is the only officially recognised assessment tool related to the circular economy at the European level. It aims to evaluate the performance of new buildings from a circular economy perspective. This paper intends to expand the field of action of the aforementioned tool to projects related to cultural heritage. Nevertheless, the Level(s) tool has some weaknesses in relation to values and attributes that need to be considered when dealing with cultural heritage. This paper proposes an evaluation framework for assessing cultural heritage renovation and reuse projects, considering all its values and the multidimensional impacts that they are able to produce (economic, social, environmental impacts) in the city. The starting point for the development of the proposed evaluation framework is the Level(s) tool by the European Commission. On the basis of critical considerations, this tool is integrated with criteria and indicators deduced from other previous studies and other official tools on this issue (Green Building Council and Heritage Impact Assessment tools). The evaluation framework is here tested to evaluate the renovation/reuse project of Villa Vannucchi, a historic building located in the city of San Giorgio a Cremano in the metropolitan city of Naples (Italy).

1. Introduction

The world in which we are living today is being transformed in a way not previously seen in recent times, producing enormous negative environmental, social and economic impacts. The time to act is now. The time to change direction before it is too late and systems collapse is now; there is still time to react.

There are several areas in which actions can be taken to avoid reaching the breaking point. One of them is related to cities, and the way they are organizing, developing and transforming themselves.

In fact, cities are the location of half of the world’s population (despite occupying only 3% of the world’s land area), producing 50% of global waste, consuming 75% of natural resources, and contributing 80% of greenhouse gas emissions [1]. As a result, it is clear that they play a critical role in achieving (or failing to achieve) sustainable development. It is an important location to carry out actions to accelerate the transition to sustainable development, to fix the (almost) broken relationship between man and nature, to achieve (or not achieve) sustainable development, and to address the challenges of our time.

Furthermore, 2020 was a significant year in the global challenge of sustainable development. The entire world faced (and is still facing) a pandemic, the worst health crisis of the century, which is causing a massive economic crisis. Cities were the epicenters of COVID-19’s spread in this highly urbanized world. As a result, the criteria upon which urban development models are based are continually questioned. COVID-19 has prompted a radical change in the urban lifestyle, and for this reason it is necessary to rethink city organization and transformation models [2].

In response to our times’ various challenges (climate change, environmental degradation and the socio-economic crisis), a number of documents have been approved to support and incentivize measures to make our country more sustainable. To that end, the United Nations (UN) approved the 2030 Agenda in 2015, which is an action plan for people, the planet, and prosperity aimed at achieving 17 Sustainable Development Goals (SDGs).

The New Urban Agenda, which was introduced by the United Nations in 2016, is the “territorial translation” of the principles of the 2030 Agenda. This document, which was approved by the UN at the UN Conference on Human Settlements and Sustainable Urban Development (HABITAT III) in Quito, Ecuador, in October 2016, represents a shared vision of what the future of our cities should be. It promotes an urban development model, which is a set of actions to rethink the planning and management of cities capable of integrating and combining the three components of sustainable development (social, economic, and environmental). As the United Nations has also recognised, in fact, if the urban transformation projects are well planned and managed, cities are able to support sustainable development.

With the 2016 “Amsterdam Pact,” the European Union (EU) put the UN Principles, Commitments, and Actions into practice [3]. Inclusion, air quality, urban poverty, housing, the circular economy, employment, adapting to climate change, energy transition, sustainable land use and nature-based solutions, urban mobility, digital transition, and innovative and responsible public procurement were all listed as 12 challenges that cities should face.

Furthermore, in 2019, the EU approved the “European Green Deal”, a “new growth strategy that aims to transform the EU into a fair and prosperous society, with a modern, resource-efficient and competitive economy where there are no net emissions of greenhouse gases in 2050 and where economic growth is decoupled from resource use. It also aims to protect, conserve and enhance the EU’s natural capital, and protect the health and well-being of citizens from environment-related risks and impacts. At the same time, this transition must be just and inclusive. It must put people first and pay attention to the regions, industries and workers who will face the greatest challenges” [4]. The built heritage and the necessity for the so-called “wave of renovations” of public and private assets to address the dual problem of energy efficiency and affordability are specifically mentioned in this document (considering that buildings are responsible for 40% of the global energy consumption).

In March 2020, the European Commission approved the new “Circular Economy Action Plan” as an integral part of the European Green Deal. In collaboration with economic actors, consumers, citizens, and civil society organisations, it offers “a future-oriented agenda for attaining a cleaner and more competitive Europe”. This communication recognizes the construction sector as one of the key sectors to promote the principles of the circular economy for the reduction of environmental effects through the building life cycle.

Furthermore, among the measures taken to respond to the consequences of the COVID-19 pandemic, the different European countries have adopted “National Resilience and Recovery Plans (NRRP)” which include, among others, a series of investments on the built heritage in general and on the cultural heritage (cultural buildings, villages, historic gardens, etc.). The aim is to improve the efficiency of the built heritage, both public and private. In fact, much of the NRRP funding has been allocated for upgrading and improving the energy efficiency (in line with the European Green Deal indications) of buildings, which today are often old, energy-intensive and low-maintenance.

The built heritage also includes the cultural heritage, a heritage characterised by particular values and attributes, a unique building subset that is “an expression of the ways of life, developed by a community and handed down from generation to generation, including customs, practices, places, objects, artistic expressions and values” [5].

The UNESCO Recommendations on Historic Urban Landscape [6] also highlight the interconnection of the development/urbanization and cultural debates. Furthermore, the New Urban Agenda (NUA) recognizes cultural heritage as a significant aspect of urban sustainable development in many sections of the Agenda, in contrast to the 2030 Agenda, where it plays a minor role (i.e., points 10. 26, 38, 45, 60, 124). Culture is seen as “a priority component of urban plans and strategies in the adoption of planning instruments, including master plans, zoning guidelines, building codes, coastal management policies, and strategic development policies that safeguard a diverse range of tangible and intangible cultural heritage and landscapes” (point 124).

The “New European Bauhaus”, launched by the European Commission in 2020, is a new design movement to make the “New Green Deal” operative in the field of the built environment. It is a “new sustainable and circular movement” that seeks to “green” the built environment. The use of renewable energy, bio-materials, the reuse of waste materials, and protection and conservation of biodiversity are the fundamental pillars of this movement. Also, this movement recognizes that cultural heritage and historical monuments can help achieve the goals of the new European Bauhaus’s development by making historical buildings more energy efficient, which is part of the New Green Deal’s “green transition” [7].

From the circular economy perspective, cultural heritage can play a significant role in the sustainable growth of the city, helping to achieve economic, environmental, and social goals at the same time.

This paper aims to propose an evaluation framework, called “Cultural Heritage Level(s)”-CHL(s)-by the authors, for evaluating cultural heritage reuse and renovation projects while taking into account the multidimensional impacts that they can produce (economic, social, and environmental impacts).

Here, the evaluation framework is tested to evaluate the renovation/reuse project of Villa Vannucchi, a historic building located in the city of San Giorgio a Cremano in the city of Naples.

The proposed evaluation framework takes into account and integrates different already existing and consolidated evaluation approaches (mostly sectoral), by critically integrating them (also with considerations deduced from case studies analyzed in previous studies), providing a comprehensive and simultaneous assessment of the impacts produced by reuse and renovation projects of cultural heritage. CHL(s) could be viewed as a sort of “technical sheet” that can also be used to compare various project scenarios.

Based on critical considerations, the proposed tool includes criteria and indicators that were taken from other previous studies and other official instruments about this issue.

The European Commission’s Level(s) tool provides the starting point for developing the proposed evaluation framework. Specifically, the proposed evaluation tool integrates the Level(s) assessment method (proposed by the European Commission), the Heritage Impact Assessment (proposed by ICOMOS), the Green Building Council certifications and some already previous scientific research conducted on the basis of concrete case studies [8]. In addition, the proposed assessment framework gives particular attention to the evaluation of the environmental impacts (through the Life Cycle Assessment) generated by a heritage reuse/renovation project. Moreover, the social and cultural effects are also strongly taken into account, as emphasized in all UNESCO and ICOMOS recommendations.

The paper is structured as follows: after the introduction in Section 1, Section 2 deals with the state of the art of evaluation tools for cultural heritage renovation/reuse projects in the perspective of the circular economy. Section 3 shows the methodology adopted in this study for the development of the proposed integrated evaluation approach. Then, in Section 4, the proposed methodology is tested in the case study of the renovation/reuse of Villa Vannucchi in San Giorgio a Cremano (Naples, Italy). After the testing phase, discussions and conclusions about strengths, limitations, and future research perspectives are presented in Section 5 and Section 6.

2. The Relation between Circular Economy and the Conservation of Cultural Heritage Values

The circular economy model is based on the principle that there is no waste in nature, but that everything can become a resource [9], and aims to operationalize the principles of sustainable development. Although there are more than 114 definitions of the circular economy in the literature, it can be generally defined as “the restructuring the industrial systems to support ecosystems through the adoption of methods to maximise the efficient use of resources by recycling and minimizing emissions and waste” [10]. Reference is made to how resource flows can be closed [11].

The United Nations also introduced, both in the 2030 Agenda and the New Urban Agenda, the circular economy model as a general development model capable of minimising negative environmental and social impacts while producing economic growth at the same time.

Numerous cities are adopting the circular economy model as an urban development model, transforming their processes from linear to circular and organizing the urban system analogously to the nature systems. A number of these cities refer to themselves as “circular cities” [12]. The starting points of the circular processes in these cities are different and include different sectors: the textile sector, the construction sector, the agri-food sector, etc. However, the circular economy model should not only refer to technical aspects (e.g., waste management), but should be a broad concept that encompasses multiple aspects of the city, such as its organisation, economy, community, and governance [12].

Cultural heritage can play a key role in the implementation of the circular processes in the city. Some principles that define the circular economy model are also mentioned in the UNESCO Recommendations on Historic Urban Landscapes (HUL), even if not explicitly [12].

In many cities nowadays, there are a large number of abandoned historic buildings; and the reason for this is that there are scarce financial resources to invest in reuse or maintenance projects (in order to keep the heritage “alive”), although cultural heritage is recognised as a driver for sustainable development [8]. It is estimated that urban buildings can have a lifespan of up to hundreds of years. When a cultural building can no longer fulfill its original function, its use should be changed. It is necessary to preserve the “historical values” of buildings when their transformation is planned.

The functional reuse strategy is able to adapt the building to new functions in order to meet evolving community needs (in line with the circular economy principles) [13]. In accordance with the Leeuwarden Declaration, “new functions are thus brought together with heritage values in an active and meaningful dialogue” [14].

For future generations to continue to enjoy cultural heritage, its integrity and authenticity should be preserved. It can be achieved through functional reuse that also allows for the preservation of the use value of cultural heritage, giving it “a new life”.

Functional reuse is an alternative to demolition and replacement or new construction, thus reducing energy consumption and waste production while also providing social benefits through the restoration and revitalization of historic landmarks [15,16,17].

According to the circular economy perspective, functional reuse provides multiple benefits, including the preservation of all cultural heritage values, including use values and intrinsic values. Furthermore, the Leeuwarden Declaration [14] emphasizes the many advantages of reusing built heritage (economic, environmental, social, and cultural benefits).

When dealing with cultural heritage, it is necessary to consider all the values that characterize it. Cultural heritage of a community is an expression of its religion, culture, and other beliefs, constituting an important aspect of community life.

It is the element through which the community can recognize itself, making it essential for the transfer of cultural identity to future generations [16]. Conservation/reuse of cultural heritage is important for maintaining a community’s identity, enhancing it, and allowing future generations to “learn” about their roots. It is important to preserve not only the tangible values, but also the intangible ones that cultural heritage has.

Since values can vary from person to person (and between different social groups), in order to identify the preferable design choices, it is necessary to have a value-based strategy that requires considerations and research into the values that are significant for a community, its transformations, and its quality of life. Therefore, in this perspective, experts (scientific knowledge) should conduct the decision-making processes with the community’s cooperation (common knowledge) in a more inclusive way.

Community participation is crucial in the mid and long-term conservation/regeneration of cultural heritage, as the latter can only occur if it is shared and accepted by the community [18].

Cultural heritage is characterized by an intrinsic value [19,20]. The concept of intrinsic value is based on ecological economics and the understanding of the autopoietic capabilities of a system [21,22,23,24].

John Ruskin and Williams Morris had previously advanced this concept [25,26] that Riegel later adopted as a “value of memory” [27]. The Burra Charter [28] was effective in introducing the concept of the intrinsic value to the field of cultural heritage conservation.

The European Commission (2014) has lately taken up the concept of intrinsic value, recognising the dual dimension of culture referred to as both a value “in and of itself” and an instrumental value [29].

The intrinsic value expresses the individual character, significance, identity, and beauty of a place, fostering a sense of interconnectedness among its inhabitants and between the community and its cultural heritage. The intrinsic value shows how a community has lived, worked, and organized itself over time.

In contrast to natural ecosystems, cultural heritage’s intrinsic value is subjective because it was created by people over time [30,31]. Therefore, it depends on the subjects who have acknowledged the value, uniqueness, beauty, and significance of that cultural heritage [8]. Not only is it personal, but it is also not static. It is mutable because the individual evaluator is mutable, due to their growing up, and also due to external influences, such as cultural and social ones [32]. The convergence of individual values produces the community values associated with a particular cultural heritage [32].

The aforementioned changeability of values associated with cultural heritage over time is related to the concept of the “shifting baseline syndrome” [33] that, “in heritage studies, not only manifests itself in change perceptions of the state of the natural and built environment, but also in change perceptions of attributed values” [34]. As people’s perception about these values change over time (this is called “intergenerational change”), the value of cultural heritage is seen in different ways at different times.

Cultural heritage links the present to the past and the present to the future by expressing the values and customs of a community. However, it is possible that different societies and even different individuals within a single community can interpret it differently. In fact, many social groups can have different beliefs and points of view, attributing different values to heritage.

Conservation and functional reuse of cultural heritage prolong its intrinsic and usevalues, allowing it to “live” for both present and future generations. It preserves a symbol of the collective identity. Therefore, the value of cultural heritage cannot be ignored in a framework for evaluating conservation and regeneration projects.

Social value is another important value associated with cultural heritage. Since the 1970s, there has been a great deal of emphasis on the social values of cultural heritage.

Given that cultural heritage has positive effects on social capital, generating and regenerating synergies, ties, and collaborative partnerships (the “glue value” of cultural heritage), it is necessary to include the social dimension when discussing cultural heritage [35,36,37,38].

Cultural heritage has the potential to be a “connective infrastructure” [39,40], that is capable of maintaining social cohesion in today’s highly fragmented society, especially in large urban agglomerations, by generating and regenerating bonds and relationships.

Cultural heritage is important for social cohesion because it organizes the community as a whole as well as its relationships (that can be generated and regenerated through conservation and functional reuse) through its symbolic power and aesthetic dimension.

Cultural heritage contributes to building social capital and social cohesion [35,38,41] by providing a context for involvement, engagement, and also fostering integration [35,42]. In addition, it encourages associations and new economic models (i.e., crowdfunding) that, in turn, contribute to the local economy.

Employment is a significant component of social capital. Given that it not only helps people “feel good”, but also acts as a “bridge” between the individual and society, it is a very important indicator of social inclusion. Through the production of job opportunities, cultural heritage also contributes to the increase in wellbeing and quality of life [32]. This aspect becomes, from a circular perspective, an input for economic productivity given that people’s wellbeing increases their productivity [43], as also recognized by several business leaders like Olivetti, Bata, and Ferrero.

Cultural heritage can enhance people’s health and well-being (different but strictly interconnected concepts) [44]. For instance, the wise old features of historical structures can promote good health. Effective orientation and physical characteristics, such as the thickness of the walls, contribute to lower temperatures inside and outside the building, thereby improving the indoor microclimatic conditions. In addition, cultural heritage enhances the quality of life in a variety of ways, including the creation of new jobs, the expansion of living and working spaces through adaptive reuse, the improvement of public spaces, etc. [45].

As stated previously, there is a growing awareness of the significance of intangible values of cultural heritage and the need to take them into account alongside (with equal weight) tangible values in the decision-making processes of cultural heritage projects [2,45,46].

2.1. Implementation Tools for Cultural Heritage Renovation and Reuse Projects

Evaluation tools play a key role in assessing and monitoring the effectiveness and efficiency of cultural heritage projects from a circular perspective, that is, to assess the (positive and/or negative) effects of the circular agenda’s strategies and projects.

Reviewing the relevant scientific literature, a number of authors note that the renovation or reuse of cultural heritage has a variety of positive effects, particularly on the environment. However, many researchers emphasise the environmental benefits (though they are not widespread) of embodied energy as energy-related advantages [17,47,48,49,50,51,52].

Several of these studies emphasize environmental benefits solely from a narrative standpoint; no indicators and quantitative data are identified to operationally quantify the environmental benefits of renovation/reuse of historic buildings.

Moreover, from an economic perspective, reusing heritage buildings is (often) cheaper and faster than demolishing and rebuilding them [53,54,55], with the exception of situations where the building needs to have its structural elements rebuilt [56].

Moreover, redeveloping a historic building is more cost-effective because it requires less time and costs less than building a new structure with the same characteristics [57]. Costs are also reduced because most of the structural components are already built and the raw materials for their possible reconstruction are already on site, reducing the duration of the work [56].

Studies have shown that preserving cultural heritage through renovation or reuse increases overall property values, which benefits both the asset being developed and the neighbouring buildings [45,58].

Functional reuse requires less materials than demolition and reconstruction, thereby decreasing embodied energy and carbon dioxide emissions. However, it should be emphasized that historic buildings have more difficulty in satisfying energy standards than new construction does [54,59,60].

However, some studies suggest that existing buildings could be upgraded to a (quite) similar energy level as new buildings, although this could significantly increase construction costs. However, this cost can be balanced if the social and cultural dimensions are considered in addition to the economic dimension. Indeed, despite the fact that reuse is sometimes more expensive than demolition and reconstruction, it is culturally [61] and environmentally [17] advantageous. For example, Baker et al. (2017) argue that renovation/reuse of cultural heritage has high significance for the local community because it “regenerates” a symbol of its identity [60].

To date, there is no officially-recognized multidimensional evaluation framework for the evaluation of cultural heritage renovation and reuse projects in a circular perspective. Sectoral approaches are the primary ones.

An officially recognized tool for the assessment of cultural heritage projects is the Heritage Impact Assessment (HIA) by ICOMOS (2011) [62]. Furthermore, in 2010, the Green Building Council (GBC) protocol was drawn up to assess and certify the sustainability of heritage renovation/reuse projects (see Section 2.1.3).

Moreover, in the past, cultural heritage assessment processes were mainly led by experts. Today, such evaluations tend to be more inclusive, recognizing the community as the most important stakeholder and increasingly involving it within decision-making processes [34]. However, the two aforementioned officially recognized evaluation tools (HIA and GBC) are based solely on expert knowledge.

The Level(s) tool is, however, the only officially recognized evaluation tool in the circular economy perspective. As explained in the following paragraphs, this tool only applies to new buildings and not to heritage renovation and reuse interventions. As previously stated, the purpose of this paper is to fill the gap left by these purely sectorial evaluation tools within this framework.

2.1.1. The Level(s) Tool by the European Commission

The Level(s) Tool [63] is the only official evaluation tool that the European Commission has adopted (in collaboration with various stakeholders, such as various producers, associations, and organizations) that is more detailed and focused on the evaluation of projects related to buildings from the perspective of the circular economy. It exclusively refers to the construction sector and provides a set of indicators for evaluating the environmental performance of commercial and residential buildings, while taking into account all aspects of their life cycles. It is not currently mandatory, but can be adopted voluntarily.

In 2017, the European Commission developed a first framework for evaluating the circular economy by grouping a number of indicators into five categories: production and consumption, waste management, secondary raw materials, competitiveness, and innovation [63]. These indicators are a good starting point, but they alone are insufficient to evaluate and monitor the complex framework of the circular economy, which consists of numerous sectors, actors, and “flows”. One of the most resource-intensive sectors is the construction industry, which accounts for half of all resources consumed, half of all energy used, a third of all water used, and a third of all waste produced [63]. Therefore, it stands as a major goal for the circular economy and sustainability policies of the European Commission.

Since the testing phase began in 2018 [64], 136 construction projects (74 residential and 62 non-residential) have utilised the Level(s) tool. The Level(s) tool’s goal is to standardize the framework for evaluating environmental sustainability in Europe using a set of indicators to assess the sustainability of various types of buildings throughout their life span, including both new and renovated office and residential buildings. Each indicator was elaborated to establish a link between the impact of a building and European sustainability targets.

In sustainable buildings, less energy is used. Furthermore, they provide healthier and more comfortable living conditions. In addition to having fewer negative environmental effects, they also have lower management costs. Level(s) encourages operators to implement both the Life Cycle Assessment (LCA) and the Life Cycle Cost Assessment (LCCA), or the assessment of life cycle costs.

In contrast to a fragmented view of individual performances, the Level(s) tool, which is still undergoing testing, promotes a holistic perspective based on life cycle assessment. It allows for the evaluation of a variety of factors, such as environmental ones, performance-related health and welfare issues, life cycle costs, and the potential future dangers of performances.

The Level(s) framework is based on six macro-objectives that correspond to the three thematic areas, listed below:

• environmental performances of the life cycle;
• health and comfort;
• cost, value and risk.

Each of the aforementioned thematic areas contains some macro-objectives, for a total of six macro-objectives, as shown in

Table 1. Thematic areas and macro-objectives of the Level(s) tool.

Thematic Areas	Macro-Objectives
Environmental performances of life cycle	Greenhouse gas emissions along a building life cycle Resource efficient and circular material life cycle Efficient use of water resources
Health and comfort	Health and comfort
Cost, value and risk	Adaptation and resilience to climate change Optimised life cycle cost

Source: [65].

.

The intended outcome is the achievement of these macro-objectives in order for buildings to contribute to the implementation of European environmental policies [65].

The different phases of Level(s) range from the gathering, assessing, and analyzing of data on a building’s performance. Additionally, as implied by its name, this instrument consists of three progressive depth levels of performance evaluation [63,65]:

• common performance assessment; the simplest level, a common reference guide for building evaluation;
• comparative performance assessment; the level that allows for the comparison between two or more equivalent buildings from the functional point of view;
• optimized performance assessment; the more complex level, which allows for the performance of a more detailed analysis and calculation models aimed at optimizing performances.

The levels illustrate ways to reduce environmental effects and can assist operators in preparing for more complex performance evaluation tools and schemes.

Given that human health is significantly influenced by policies and actions taken in many other sectors that are beyond the healthcare field but affect health through various pathways, assessing the health effects of circular economy projects adds value to the decision-making process. Good health conditions are an essential component of the circular city because, from the perspective of human-centered development, they reduce costs associated with illness, malaise, etc.

Since the construction sector produces the greatest number of interdependencies overall, it is important to examine it from the perspective of the circular economy. Along with producing economic productivity and environmental sustainability, this also helps to promote “social” productivity, such as through creating jobs. Due to its ability to simultaneously satisfy the needs of economic, environmental, and social sustainability, the construction industry is an ideal starting point for implementing the circular model, thereby minimising the conflict between the green economy and the social economy.

Although quite comprehensive, the Level(s) tool does not specifically mention cultural heritage. However, given that the European Union itself recognizes the significant role that cultural heritage plays as one of the drivers of sustainable development, it is essential that the EU specifically addresses the issue related to implementation tools for the functional reuse of cultural heritage by providing a comprehensive and adequate list of multidimensional indicators (economic, environmental, social, and cultural).

In a recent paper, Ferrari et al. (2022) assert that there are different evaluation methods for green building certification. Among them, the LEED (Leadership in Energy and Environmental Design) protocol is the most similar to Level(s) (81% affinity), while BREEAM (BRE environmental Assessment Method) and DGNB (German Sustainable Building Council) are more similar in terms of regulations and life cycle coverage. In contrast, WELL (Well building standards) and CASBEE (Comprehensive Assessment System for Building Environmental Efficiency) are objectively far from meeting Level(s) principles [66].

All of these certifications use Life Cycle Assessment (LCA) as an operational assessment tool to quantify the potential negative impacts related to a design project.

The Level(s) Framework also employs the Life Cycle Assessment (LCA). The entire life cycle of a building or product can be evaluated using Life Cycle Assessment. It is used to evaluate all environmental effects resulting from the extraction of raw materials to the demolition of a building. These effects include those associated with the supply of raw materials, their production, transportation, maintenance, repair, and disposal, as well as the greenhouse gas emissions produced by a building and the materials it contains [67].

Numerous studies acknowledge that using LCA alone to evaluate design alternatives for building renovating is insufficient. It is necessary, for example, to combine LCA with a participatory approach that involves residents/users in the project’s definition phase in order to comprehend the actual needs of those who live in the building.

In this regard, a number of studies emphasise the importance of involving diverse stakeholders in the renovation and reuse project of historic buildings.

For example, Claude et al. (2017) argue that it is necessary to activate a “living lab methodology” among all the stakeholders involved in the building renovation/reuse projects. Claude et al. tested the “living lab methodology” (reaching positive results) for the thermal renovation of some historic buildings in the Cahors historic centre, France [68]. From the design phase to the implementation phase, numerous participants have been involved (i.e., craftsmen, students, end-users, local authorities, material producers). This allowed for an acceptable and efficient building renovation solution.

According to Wender et al. (2014), LCA undervalues the important role of stakeholder involvement in guiding the decision models, thereby reducing the social reliability and significance of results [69]. The realization of an “anticipatory” LCA can be used to investigate the potential future environmental costs associated with a developing technology. These anticipatory techniques can generate alternative research scenarios and provide an operational tool to support environmentally responsible projects by identifying the most pertinent uncertainty and involving research and development decision-makers [69].

To evaluate the public perception based on the livability, comfort, use, and esthetic of buildings, stakeholder engagement for defining the built environment is necessary [70].

In the research conducted by Göswein et al., it is recognized that the stakeholders involved in a regeneration project express different priorities that should be considered. Therefore, it is important to assess the potential behavior of users [71].

Additionally, they argue that the literature review on the topic shows that “involvement” emerges at multiple phases, particularly during project specification, concept development, and prototyping.

According to a study by Kaulio et al. (2016), there is the necessity to involve users in the design process in order to better meet their needs [72]. However, this is uncommon in practice. Kaulio et al. (2016) investigate the role of users in the design process and propose the use of virtual design and construction to permit the analysis of virtual users and to encourage the direct participation of real users [73].

In this light, Göswein et al. (2020) assert that it could be interesting to determinate decision criteria and relative weights in a Multi-Criteria Decision Analysis starting from user requests (MCDA) [71]. Göswein et al. (2020) conducted an extensive research on the integration of Life Cycle Assessment (LCA) with multi-criteria evaluation methods by performing a thorough literature review [71]. In this study, it is highlighted that Seager and Linkov (2008) emphasised the value of coupling LCA with MCDA in order to better understand trade-offs and future multiple perspectives to build redevelopment interventions [74].

Furthermore, other factors, such as the cost of interventions, the achievable thermal comfort, and the level of structural performance [74] can be considered in an MCDA. It is important to note that different stakeholders involved in these processes will attribute different importance to the indicators identified to carry out the MCDA [72]. In this regard, there is the possibility of using specific weight sets or value functions for each stakeholder group [75].

2.1.2. Testing Projects of the Level(s) Tool

The implementation of the Level(s) tool is still in its early stages. In fact, to date, there

are few documents about case studies in which it has been used. These are mainly reports from countries that have collaborated with the European Commission to test the evaluation method and determine its strengths and weaknesses.

The Level(s) tool was launched in 2017 by the European Commission, which in 2018 invited member states to participate in the test phase to suggest integration to improve the assessment tool. The two years of testing and public consultation ended in 2020.

More than twenty nations, including Luxembourg, Denmark, the Netherlands, Belgium, the United Kingdom, France, Spain, Portugal, Germany, Italy, Austria, Malta, Slovenia, Croatia, Greece, Romania, Poland, Lithuania, Sweden, Finland, the Czech Republic, etc., participated in the test phase. This method was utilized by experts from each country to certify the sustainable design of approximately 130 buildings.

In Finland and Slovenia, the Ministry of the Environment and the Green Building Council invited planners to evaluate the sustainability of eighteen building projects using the Level(s) assessment method. Participants included public sector representatives, construction companies, builders, consultants, and manufacturers of building materials. The majority of the projects involved new residential buildings, schools, offices, sanitary facilities, and dormitories. Each project was completed using innovative materials and technologies for illumination, energy efficiency, drainage in health systems, etc. The carbon footprint calculation supported the designers in deciding, in the ex-ante evaluation phase, among alternative project scenarios. Furthermore, the “Building Information Model” (BIM) models have facilitated the study through an almost immediate data collection project.

For each case study, an analysis of the impacts for a 60-year forecast period was conducted, resulting in a Life Cycle Assessment. The LCA (elaborated using One Click LCA software) was used as the assessment tool to collect the data necessary to meet the Level(s)’ proposed indicators. Only two of these projects involved “building refurbishment”.

Erlandsson et al. (2019) conducted the Level(s) test on the Skanska Backkra residential building in Sweden (Sweden). At the conclusion of the analysis, they proposed a number of methodological integrations to the Level(s) method, such as:

• to define common regulations regarding the scenario setting for design;
• to define common standards for data collection;
• to define a common digital report for sharing results;
• to improve the use of “Building Information Modelling” (BIM) in the redaction of the project. Integration of BIM and Level(s) can be useful for defining a better design process [76].

In Spain, the Level(s) test was used to evaluate the sustainability of residential and commercial construction projects. A BIM model of each building was created. At the end of the project definition, the Level(s) evaluation method was applied to evaluate the project’s environmental impacts. According to the results, additional actions are required to improve the sustainability of the buildings. Furthermore, the integration of BIM and LCA software was highly effective.

In France, the Alliance HQE-GBC coordinated the testing of the Level(s) methodology in nine projects of renovation/reuse and new construction of offices and residences. Also in this instance, the BIM methodology was used to support the Level(s) tool, thereby enhancing the efficiency of the evaluation process.

In Italy, the “Green Building Council” is implementing a number of initiatives (seminars, meetings, workshops, etc.) to inform the professionals on the use of Level(s) tool, with the goal of integrating its indicators into the existing certification systems in order to collect a comparable set of data among projects across Europe.

When the testing process concluded in 2020, the European Member States convened in separate meetings to determine the tool’s strengths and weaknesses based on the analysis of case studies, and they then released an updated version of the tool.

The main consideration from the “test phase” concerns the revision of the content of the different “levels” referred to in the project and building life cycle.

In particular, the first three levels were revised and modified as follows:

• Level 1 applies to the preliminary design and evaluates it qualitatively;
• Level 2 applies to the executive design and construction phases for quantitative performance evaluation;
• Level 3 applies to the completion of construction and during the building’s use phase to measure and monitor performance [77].

The new Level(s) edition expands on the concept of the circular approach to building design throughout its life cycle by focusing on how to close the performance gap between design and actual performance in use.

The need to strengthen the relationship between BIM, LCA, and Level(s), which is becoming increasingly consolidated in the design and planning process, is an additional important consideration that emerged during the workshops.

Some European nations emphasised the need to provide a Level(s)’guide translated into each language in order to simplify and clarify environmental assessment operations. In addition, the need to develop a European Common platform for sharing Level(s) application results has emerged.

Only Denmark has emphasised the need to combine environmental and social indicators within the Level(s) framework.

2.1.3. Green Building Council and Heritage Impact Assessment tools

Heritage Impact Assessment (HIA) and Green Building Certification (GBC) are two further important evaluation tools that can contribute to the assessment of renovation/reuse projects of historic buildings.

The Heritage Impact Assessment (HIA) is an evaluation framework proposed by ICOMOS in order to operationalize the Historic Urban Landscape Recommendations by UNESCO in 2011 [78]. This is the only official methodological guideline for assessing the effects of cultural heritage and landscape valorization and regeneration projects [78].

Specifically, the “Guide to Cultural Impact Assessment” (HIA) refers to sites on the World Heritage List (ICOMOS, 2011) that are recognized as having “Outstanding Universal Value” (OUV) [62].

This method is considered as a tool to go beyond the limits of the Environmental Impacts Assessment (EIA). In fact, when EIA is applied to cultural heritage, it disaggregates all its possible attributes and assesses the impacts separately, adopting specific perspectives [79]. In this view, the HIA is able to assess the impacts of a large urban development project and the potential vulnerability of an asset/site undergoing a change in urban policies (e.g., changes in land use and urban planning policies, management of infrastructure and tourism flows, etc.) [79].

However, it is evident that the ICOMOS recommendations place a greater emphasis on the procedure’s effectiveness than on the expected outcomes from the standpoint of protecting heritage attributes [56]. Consequently, a more global and objective approach to the Historic Urban Landscape is still required for taking into account the relationship between attributes and values in the context of development.

Furthermore, since 2011, the ICOMOS guide has been applied to different operational case studies for assessing the impact of urban regeneration projects and projects for the reuse of historic buildings. Best practices include the regeneration of the Liverpool waterfront, the realization of Stockholm Bypass Road, the Wald-schlösschen Bridge project in Germany, the Cologne Cathedral in Germany, the New Railway Tunnels in Germany, the project of Gallery Lower Austria, and many others [80].

Also on the SoPHIA platform, there are several case studies that show how HIA was used. This platform was developed as part of the SoPHIA Horizon project (Social Platform for Holistic Impact Heritage Assessment). The goals of the project are to encourage group reflection on the impact evaluation and effectiveness of interventions in the European historical environment and cultural heritage at the urban level [81].

The research work of SoPHIA is structured around four key analytic impact dimensions: social, cultural, economic, and environmental impacts. These dimensions provide a framework for identifying the most significant obstacles and opportunities associated with interventions in cultural assets in Europe [82]. As part of the SoPHIA study, twelve case studies have been presented, including a landscape site, two museums, three cultural districts, a place of memory, an island, a historic city centre, and a monastery [81].

Rogers’s [82] study demonstrates that HIA should become a mandatory methodology when defining redevelopment projects for cultural buildings or entire neighbourhoods in order to make decision-makers aware of the potential effects of human actions on cultural heritage.

According to some researchers, conducting a comprehensive HIA requires a multidisciplinary professional team to provide comprehensive information and an in-depth assessment using a variety of approaches and methods across multiple dimensions. Such a comprehensive and interdisciplinary approach can enhance decision-making and, consequently, the preservation of cultural resources in policies for sustainable development [83]. Again, a study by Ashrafi et al. [83], in collaboration with WHITRAP and ICCROM [84], analysed additional case studies in which HIA was applied. They argued that multisectoral collaboration is necessary to improve urban development strategies based on their analysis of these case studies. In addition, the dialogue among experts in different disciplines is essential because it would increase the effectiveness of HIA by enhancing the perception, knowledge, and skills of stakeholders, with the aim of preserving world heritage properties exposed to the threats of future development.

ICCROM, IUCN, ICOMOS, and the World Heritage Centre of UNESCO are collaborating to develop and disseminate the new version of Heritage Impact Assessment. This new document aims to address the current gaps and challenges that World Heritage sites face with regard to impact assessment processes [84].

This document will result in the development of an impact assessment toolkit for World Heritage properties, based on a framework applicable to both natural and cultural environments [84].

Green Building Council (GBC) Italia launched a protocol to certify the sustainability of renovation/reuse projects for cultural heritage after analysing the scientific literature on evaluation methods for testing the sustainability of such projects. GBC is a non-profit organization whose members include the most competitive companies, associations, and professional communities operating in the sustainable building sector. GBC Italia is a member of the World GBC, a network of national GBCs present in more than 70 countries and the world’s largest sustainable construction market-focused international organization [85].

The Green Building Council (GBC) is very active in the green certification of historic building reuse projects, developing a manual to guide the designers to obtain the certification. “GBC Historic building” is a voluntary certification protocol that assesses the level of sustainability of conservation, rehabilitation, restoration and integration of historic buildings with different uses [85].

Moreover, this certification is applied to historic buildings that constitute “material evidence with a value of civilization" that were built before 1945 [85].

The GBC Historic Building assesses the performance of buildings from an overall perspective throughout their entire life cycle, both during the design phase of interventions and their subsequent operation. The sustainability of a building is assessed using a variety of indicators clustered by thematic areas (environmental categories) that define GBC rating systems, as shown in

Table 2. Thematic areas (environmental categories) of GBC.

Thematic Area	Assignable Points
Historical value (VS)	20
Site Sustainability (SS);	13
Water Management (GA);	8
Energy and Atmosphere (EA);	29
Materials and Resources (MR);	14
Indoor Environmental Quality (IQ);	16
Innovation in Design (IP);	6
Regional priority (RP)	4

Source: [86].

. To each thematic area corresponds a set of sub-criteria, and each is assigned a numerical value as a score. According to the guide, the distribution of credits among the different thematic areas is determined in relation to their effects on environmental and human health [85].

GBC Italy has already issued a number of certifications that can be considered as best practices for future certifications of historic buildings, such as the Meis in Ferrara, the Guinelli building in Ferrara, the Santander building in Turin, and the Scuderie of Sant’Apollinare in Perugia [85].

3. Methodology

As stated previously, the aim of this research work is to propose an evaluation framework for assessing cultural heritage renovation and reuse projects from the perspective of the circular economy (Figure 1). The starting point for the development of the proposed evaluation framework is, as mentioned before, the Level(s) tool as used by the European Commission. This tool can also be used, with appropriate integrations, for evaluating the renovation/reuse projects of cultural heritage, which represents a particular type of built heritage, characterized by different values.

According to a previous study by Nocca et al. [8], the Level(s) tool has been integrated with other thematic areas and indicators in order to include in the framework the various aspects and values associated with cultural heritage projects.

In particular, Nocca et al. [8] identified three new thematic areas to be added to those identified by the European Commission (environmental performances of life cycle; health and comfort; cost, value and risk):

• social value;
• intrinsic value;
• state of conservation (and related use value).

The above three thematic areas are essential to have (together with the other three thematic areas identified by European Commission) a complete and omni-comprehensive evaluation framework of cultural heritage projects, with the awareness that cultural heritage is characterized by both tangible and intangible values (as highlighted in the previous sections). Therefore, indicators related to intrinsic value (expressed for example in terms of attachment to place) and social value (expressed for example in terms of generated social relationships) have been considered in the proposed evaluation framework. This represents one of the aspects that differentiates the proposed evaluation framework from the Level(s) tool, which, being related to new construction buildings, neglects these kinds of values. As was previously mentioned, the incorporation of such values into the evaluation process requires the integration of expert and common knowledge.

Therefore, the six thematic areas are able to cover all dimensions: the environmental, social, cultural and economic. The environmental and the economic ones were already included in the European Commission’s Level(s) tool, and the others were identified by Nocca et al. [8].

The CHL(s) proposed in this paper identifies additional indicators to further integrate those proposed by Nocca et al. [8]:

• Indicators deduced from the Green Building Council (GBC) manual;
• Indicators deduced from the Heritage Impact Assessment.

Some GBC indicators were not included in the proposed framework only because their corresponding measures were already included in the indicators identified by Nocca et al. [8]. Therefore, they would constitute a duplication. Regarding the indicators deduced by the GBC, the proposed evaluation framework also incorporated the scores assigned by the guide. The HIA indicators selected for this study are capable of evaluating the various impacts of a renovation/reuse project, in reference, for example, to impact magnitude, scale and severity of change/impact, value of the heritage asset and the significance of impact. The indicators deduced from HIA are mainly included in the cultural thematic area.

Additionally, the indicators of the proposed evaluation framework (CHL(s)) refer to three different levels of territorial scale: the macro scale (Ma), meso scale (Me), and micro scale (Mi). The first one refers to regional, national and international levels. The meso scale is related to neighbourhood level and city level. The micro scale refers to building level and citizens’ level.

In conclusion, the set of thematic areas and indicators, deduced from the Level(s) tool, the study by Nocca et al., the GBC, and HIA, is shown in

Table 3. Indicators of the proposed evaluation framework CHL(S).

THEMATIC AREA 1–Life Cycle Environmental Assessment
Macro-objective 1: Greenhouse gas emissions along a Buildings Life Cycle
Indicator	Unit of measure	Territorial scale	Source
Use stage energy performance	kWh/m2/yr	Micro	[63]
Life cycle Global Warming Potential	Kg CO2e/m2/yr	Micro	[63]
Macro-objective 2: Resource efficient and Circular Material Life Cycles
Construction and demolition waste and materials	kg waste and materials per m2 of total useful floor area	Micro	[63]
Reuse of materials in projects related to cultural heritage	%	Micro	[87]
Re-use of buildings: retaining existing technical elements and finishes	Qualitative (scale 1–3)	Micro	[86]
Macro-objective 3: Efficient use of water resources
Use stage water consumption	m3/occupant/yr	Micro	[63]
Reducing external water use	Qualitative (scale 1–3)	Micro	[86]
Water consumption metering	Qualitative (scale 1–2)	Micro	[86]
THEMATIC AREA 2–Health and comfort and wellbeing
Macro-objective 1: Healthy and comfortable spaces
Indoor air quality Ventilation rate (air flow) CO2 Particulates Relative humidity	Liters per second per square meter (l/s per m2) Parts per million (ppm) μg/m³ % ratio of partial to equilibrium vapour pressure	Micro	[63]
Time out of thermal comfort range	% of the time out of range of defined maximum and minimum temperatures during the heating and cooling seasons	Micro	[63]
Lighting and visual comfort	Useful Daylight Illuminance (UDI)	Micro	[63]
Acoustics and protection against noise	Yes or not	Micro	[63]
Perception of wellbeing	% Percentage of people feeling in a wellbeing condition inside the building	Micro	[45]
Ambient air monitoring	Qualitative (scale 1–2)	Micro	[86]
Control and management of installations: thermal comfort	Qualitative (0–1)	Micro	[86]
Thermal comfort: design	Qualitative (0–1)	Micro	[86]
Renewable energy	Qualitative (scale 1–6)	Micro	[86]
THEMATIC AREA 3–Cost, value and risk
Macro-objective 1: Adaptation and resilience to climate change
Life cycle tools: Scenarios for projected future climatic conditions	Protection of occupier health and thermal comfort. Simulation of the building’s projected time out of thermal comfort range for the years 2030 and 2050.	Micro	[63]
Macro-objective 2: Optimised life cycle cost and value
Life cycle costs	€/m²/yr	Micro	[63]
Real estate value of surrounding buildings	€/sqm	Meso	[45,87]
THEMATIC AREA 4–Social Value
Macro-objective 1: Generation and regeneration of the social capital
Number of new jobs related to functional reuse projects (employment sub-category)	N./project	Micro	[45,87]
Number of associations, number of volunteers, number of cooperative enterprises related to functional reuse projects (social cohesion sub-category)	N./project	Micro	[45,87]
THEMATIC AREA 5–Intrinsic Value
Macro-objective 1: Generation and regeneration of the intrinsic value
Place attachment and local identity (following the implementation of projects related to cultural heritage)	Qualitative (scale 1–5)	Meso	[45,87]
Sense of place in sites	Qualitative (scale 1–5)	Meso	[45,87]
Value of heritage asset (built heritage or Historic Urban Landscape)	Very High, High, Medium, Low, Negligible, Unknown potential	Micro	[62]
THEMATIC AREA 6–State of conservation
Macro-objective 1: Enhancing the state of conservation and prolonging use value of the building
Overall state of preservation of the building	Qualitative (very low, low, moderate, high, very high)	Micro	[62]
Scale & severity of change/impact	No Change, Negligible change, Minor change, Moderate change, Major change	Micro	[62]
Significance of effect or overall impact (either adverse or beneficial)	Neutral; Slight; Moderate/ Large; Large/very Large; Very Large/ Slight	Micro	[62]
Conservation of the geometric features	Qualitative (Yes or Not)	Micro	[88,89]
Recognizability and acceptability of the transformations	Qualitative (high-medium-low)	Micro	[88,89]
Diagnostic investigations of materials and forms of degradation	Qualitative (scale 1–2)	Micro	[86]
Advanced investigations: diagnostic investigations of structures and structural monitoring	Qualitative (scale 1–2)	Micro	[86]
Reversibility of conservation action	Qualitative (scale 1–2)	Micro	[86]
Compatibility of destination use and settlement benefits	Qualitative (scale 1–2)	Micro	[86]
Programmed Maintenance Plan	Qualitative (scale 1–2)	Macro	[86]
Recovery and rehabilitation of degraded sites	Qualitative (scale 1–2)	Macro	[86]
Site development: rehabilitation of open spaces	Qualitative (scale 1–2)	Macro	[86]

. The unite of measures, both quantitative and qualitative, are those indicated by the tools taken as reference (Level(s), GBC, HIA and Nocca et al.)

4. Case Study: Villa Vannucchi in San Giorgio a Cremano (Italy)

The CHL(s) proposed tool has been tested in the renovation/reuse project of Villa Vannucchi, one of the many villas of the “Golden Mile”, in San Giorgio a Cremano (Naples, Italy) (Figure 2). The building is approximately 1200 square metres in size and is surrounded by a very large green park. The garden is a typical “Italian garden” with long avenues leading to a monumental fountain in the centre.

The 1980 earthquake caused severe damage to the property. Subsequently, in 2006, it was transferred from private ownership to the municipal property of San Giorgio a Cremano and subjected to an extensive refurbishment project. Three years later, the reorganization of the park was completed.

Villa Vannucchi is located in the “UNESCO buffer zone” and is part of the “Somma, Vesuvius, and the Golden Mile” UNESCO Man and the Biosphere (MAB) Reserve in the Gulf of Naples. The above mentioned buffer zone encompasses the territory included in the Vesuvius National Park as well as the surrounding coastal strip, comprising the city of Pompeii and the 16th- and 17th-century Vesuvian villas located along the so-called “Golden Mile,” which represents an architectural heritage of exceptional value.

Today, the Villa Vannucchi serves as the headquarters for Pegaso Telematic University, while the park serves as an urban park. Additionally, the villa’s rooms from the 17th century are used for periodic events organised by the municipality and various organizations.

4.1. Renovation Project of Villa Vannucchi

Two researchers (Dr. M. Angrisano and Dr. P. Iodice), under the direction of Professors Francesco Fabbrocino and Luigi Fusco Girard (Pegaso University), elaborated a plan for the energy renovation/reuse of Villa Vannucchi in 2021. This project’s objective was to reduce the negative effects of heating and cooling interior spaces, which are responsible for a high energy consumption. Through specific project actions, the building’s energy operation was optimized.

Similar to all historical buildings, the livability of the villa’s interior spaces is compromised by space heating and cooling problems, which require a substantial amount of electricity consumption [89].

For this reason, the energy project for the renovation/reuse of the villa began with some technical inspections of the external and internal walls. During these investigations, it was determined that the southeast wall of the building is the one most susceptible to moisture and infiltration issues due to its completely exposed facade. Over time, infiltration has caused problems with mould, plaster swelling, and wooden frame damage.

For this reason, a thermoscanner was utilised to conduct a more thorough investigation of these walls. The objective was to establish the degree of thermal insulation of the walls, identify thermal bridges, analyse the plaster in the process of detachment, and examine the receptivity of the materials.

During measurements, the following emissivity coefficients were utilised: wood only (0.85), window (1.00), and wall (0.95) [90]. The investigation revealed that the majority of thermal bridges are between windows and their adjacent walls. The presence of windows and doors with a single pane of glass has a significant impact on the thermal insulation of the rooms.

The investigation and knowledge of the existing building are especially important in the case of historic buildings, as it enables the project to be oriented towards design choices that guarantee the protection of the intrinsic value of the building elements, avoiding unnecessary oversizing of systems or overlap of any insulating layers [88].

After the investigation phase, three different design alternatives were developed. First, a BIM model of the villa was elaborated. This model allows for the assessment of the environmental impact more quickly. Therefore, using One Click LCA software (by Bionova), a Life Cycle Assessment was conducted on the above three design alternatives. This software is the same used for the testing of the case studies by the member countries of the European Commission.

The three project scenarios are as follows:

• Scenario A includes the replacement of the roof membranes with FPO/PVC-P waterproofing reinforced with polyester, the installation of a second window frame for all of the interior windows, and the use of breathable exterior plastering on the building’s facades;
• Scenario B adds to scenario A photovoltaic panels and a thermal coat on the internal facade of the building with expanded polystyrene insulation panels.
• Scenario C is a combination of Scenarios A and B, with the exception that the thermal coat in Scenario C is made of hemp panels [89].

As mentioned previously, for the aforementioned design scenarios, a life cycle assessment was processed by One Click LCA software to identify, among the three scenarios, the one that most minimizes environmental impacts in terms of CO₂ emissions.

The results of LCA demonstrated that conventional energy interventions for historic buildings (using polyurethane panels for wall insulation, as in the scenarios A and B) have significant negative environmental effects in terms of CO₂ emissions [90]. This does not happen when they are employed because hemp-based insulation panels include a significant amount of “biogenic carbon” (common in bio-based materials), which has the ability to lower atmospheric carbon dioxide levels [89]. This indicates that carbon is incorporated into bio-based products even during development [91].

Consequently, Scenario C emerges as the preferable one. It consumes less operational energy compared to options A and B. By utilising hemp-based products, the materials extraction indicator was significantly reduced.

This application demonstrates that, compared to conventional materials, the use of hemp material for thermal insulation of walls significantly reduces the percentage of environmental impact over the entire material life cycle [89]. This was attributed to the fact that, as a plant grows, it removes a considerable amount of CO₂ from the environment.

Therefore, in this paper, the result of the LCA identifying the preferable design alternative for the energy renovation/reuse of the villa (the project utilising hemp insulation panels) was incorporated into the proposed CHL(s) tool. Where data could not be determined, “n.d.” (not defined) was indicated in

Table 4. CHL(s) applied to Villa Vannucchi renovation/reuse project.

THEMATIC AREA 1–Life Cycle Environmental Assessment
Macro-objective 1: Greenhouse gas emissions along a Buildings Life Cycle
Indicator	Unit of measure	Territorial scale
Use stage energy performance	260.000 KWh/a 216.66 KWh/ m2/yr	Micro
Life cycle Global Warming Potential	87.52 CO2e/m2/yr	Micro
Macro-objective 2: Resource efficient and Circular Material Life Cycles
Construction and demolition waste and materials	2536 kg/m2	Micro
Reuse of materials in projects related to cultural heritage	80 % (materials reused for park intervention)	Micro
Re-use of buildings: retaining existing technical elements and finishes	3	Micro
Macro-objective 3: Efficient use of water resources
Use stage water consumption	200.000 m3/occupant/yr	Micro
Reducing external water use	2	Micro
Water consumption metering	1	Micro
THEMATIC AREA 2–Health and comfort and wellbeing
Macro-objective 1: Healthy and comfortable spaces
Indoor air quality-Ventilation rate (air flow)	5200 l/s (four air changes)	Micro
Time out of thermal comfort range	30 %	Micro
Lighting and visual comfort	480.000 lumens	Micro
Acoustics and protection against noise	Yes	Micro
Perception of wellbeing (prevision)	80%	Micro
Ambient air monitoring	2	Micro
Control and management of installations: thermal comfort	1	Micro
Thermal comfort: design	1	Micro
Renewable energy	4	Micro
THEMATIC AREA 3–Cost, value and risk
Macro-objective 1: Adaptation and resilience to climate change
Life cycle tools: Scenarios for projected future climatic conditions	n.d.	Micro
Macro-objective 2: Optimised life cycle cost and value
Life cycle costs	80,000 €/yr	Micro
Real estate value of surrounding buildings (prevision after intervention)	2500 €/sqm	Meso
THEMATIC AREA 4–Social Value
Macro-objective 1: Generation and regeneration of the social capital
Number of new jobs related to functional reuse projects. Employment sub-category. (Prevision)	20	Micro
Number of associations, number of volunteers, number of cooperative enterprises related to functional reuse projects. Social cohesion sub-category. (Prevision)	3	Micro
THEMATIC AREA 5–Intrinsic Value
Macro-objective 1: Generation and regeneration of the intrinsic value
Place attachment and local identity (following the implementation of projects related to cultural heritage). (Prevision)	5	Meso
Sense of place in sites (prevision)	5	Meso
Value of heritage asset (built heritage or Historic Urban Landscape)	High	Micro
THEMATIC AREA 6–State of conservation
Macro-objective 1: Enhancing the state of conservation and prolonging use value of the building
Overall state of preservation of the building	Moderate	Micro
Scale and severity of change/impact	Negligible change	Micro
Significance of effect or overall impact (either adverse or beneficial)	Slight	Micro
Conservation of the geometric features	Yes	Micro
Recognizability and acceptability of the transformations	High	Micro
Diagnostic investigations of materials and forms of degradation	2	Micro
Advanced investigations: diagnostic investigations of structures and structural monitoring	2	Micro
Reversibility of conservation action	2	Micro
Compatibility of (current) destination use and settlement benefits	2	Micro
Programmed Maintenance Plan	1	Macro
Recovery and rehabilitation of degraded sites	2	Macro
Site development: rehabilitation of open spaces	2	Macro

.

Specifically, the indicators used for the CHL(s) evaluation framework are:

• Use stage energy performance: 216,66 kWh/m2/yr;
• Life cycle global warming potential: 87.52 Kg CO2e/m2/yr
• Use stage water consumption: m3/occupant/yr 200.000 [91].

Furthermore, a “participatory process” involving different stakeholders was also activated to define the three design solutions in order to collect the different needs and perceptions of those who use (enjoys and benefits from) the villa. The support of common knowledge is important for both the defining of design choices (that so they are most shared by the community that experiences the project sites) and the assessment of the subjective-perceptual indicators that characterise the evaluative framework of cultural heritage, which is characterised by both tangible and intangible values. Thus by both quantitative and qualitative subjective indicators.

Therefore, a questionnaire was created and sent (by e-mail via the “Google form platform”) to professors, students, office workers, and associations. In three months, roughly 150 individuals responded to the survey. The questionnaire’s purpose was to determine the perceptions and perspectives of the building’s occupants (both of the state of the art and of the project). In order to understand the perception indicators, various images (renders) and videos relating to the state of the art and the scenarios were shown to the interviewees, who were asked to rate them on a scale from 1 to 5.

After analyzing the survey results, it was determined that humidity is a major issue in almost all of the rooms. This unfavourable microclimate causes rooms to feel colder, particularly during winter. As a result of the inefficiency of the single-glazed wooden window frames, there are instances of flooding in certain rooms (those facing east) during rainy weather. The continuous use of air conditioners to heat the villa was deemed unsustainable. This method is comparable to the “anticipatory LCA” outlined in Section 2.1.2.

4.2. The Evaluation of the Villa Vannucchi Project through CHL(s)

The CHL(S) proposed evaluation framework was applied to Villa Vannucchi, including the data and information highlighted in the previous paragraph. The indicators sheet (Table 4) has been filled. The indicators include both quantitative and qualitative data.

Data were derived from various sources, including the LCA application results, the energy project, and the submitted questionnaire.

As stated previously, the units of measure used to populate the indicators (both quantitative and qualitative) are those of the studies used as a basis for the proposed evaluation framework’s development.

In order to evaluate the impact of cultural heritage functional renovation/reuse, data resulting from Life Cycle Assessment (LCA) were used to compile the specific indicators listed in Table 4. This is an ex-ante evaluation of the Villa Vannucchi retrofit project, specifically of Scenario C, that is the preferable alternative deduced from the previous evaluation (through LCA).

5. Discussion

This study aims to contribute to the scientific landscape by providing a comprehensive evaluation framework capable of assessing the impact of reuse/renovation projects of cultural heritage, integrating specific consolidated evaluation tools examined in the literature review of this paper (see Section 2).

The results derived from the application of CHL(s) to the Villa Vannucchi case study provide a comprehensive understanding of the environmental, economic, and social-cultural impacts produced by the renovation project. It is a useful evaluation tool capable of supporting planners in decision-making processes by analysing the multidimensional effects produced, i.e., “measuring” its “sustainability performance”.

The Villa Vannucchi renovation project was evaluated using specific indicators, which were then incorporated into the CHL(s) evaluation framework (see Table 4). These indicators are derived from LCA conducted on Villa Vannucchi and from the questionnaire (see Section 4.1).

LCA was used to evaluate three project scenarios for renovation/reuse of the villa in order to determine the “project with the lowest environmental impact”.

LCA measured carbon emissions, impacts related to material use, water consumption, indoor air quality, use stage performance, and global warming potential over the product’s life cycle.

LCA have revealed good results in terms of CO₂ emissions released in the atmosphere by the planned project activities. This is because in the “satisfying project” [92] uses hemp-materials for the wall insulation. Biogenic CO₂ is prevalent in hemp materials and more generally in biomaterials. These are substances that have produced or grown while removing carbon dioxide from the atmosphere [89].

In this framework, the life cycle approach can significantly support designers and decision-makers in considering various environmental effects (as GHG emissions) based not only on the operational energy performance of the building after construction, also known as the energy performance level of the building, but also on the emissions produced over the entire life cycle of the construction work and building (re)use.

The CHL(s) were used to evaluate the impacts of scenario C (satisfying project). Nonetheless, it might be worthwhile to reassess it after the interventions have been implemented to determine whether the predictions were accurate.

All the LCA results were used to populate the indicators related to thematic areas 1 (Life Cycle Environmental Assessment) and 2 (health and comfort and wellbeing) of the CHL(s) evaluation framework.

Indicators related to the reuse of waste materials (thematic area 1, macro-objective 2) from construction operations will be used for some planned park interventions in the context of the circular economy (thematic area 1, macro-objective 2).

The indicators of macro-objective 3 (the efficient use of water resources) of thematic area 1 can be considered satisfactory in terms of results, thanks to the introduction in the project of a rainwater recovery system planned for the irrigation of the park.

Analyzing the results of the indicators related to thematic area 2 (health, comfort and wellbeing), it can be observed that they are very encouraging, particularly due to the renovation/reuse project’s maintenance programme for the villa. In this project scenario, sensors will be installed in the future to monitor air quality and determine future humidity levels.

In the third thematic area (cost, value and risk), management costs were also estimated in order to have a forecast of the expenditures to be incurred for the realization of the project.

Moreover, an important indicator of this third thematic area refers to the increase in the real estate value of surrounding buildings. In fact, a forecast of the increase in real estate values of the asset near the villa has been identified.

The energy retrofit projects of the historic buildings should combine the need to adapt the building to the changing needs of the community with the need to preserve the cultural heritage’s intrinsic value [19]. For this reason, the CHL(s) evaluation framework also considers the effects related to the social and cultural dimensions in thematic area 4 (social value) and thematic area 5 (intrinsic value).

Indicators related to “sense of place” and “place attachment and local identity” that were assessed via questionnaires revealed a high level of performance from this perspective. The villa has always been a symbol of the city’s history, as significant and nationally recognised events have constantly been held in the park.

Important support was provided by the indicators derived from the HIA because they allow for the evaluation of the “value of heritage asset” (considered “high”), the “overall state of preservation of the building” (considered “moderate”), the “severity of change” (considered “negligible”), and the “significance of effect or overall impact” (considered “minor”). In the sixth thematic area (state of conservation), the preservation status of the villa was evaluated.

Through this study conducted for Villa Vannucchi, a comprehensive data sheet containing indicators pertaining to all the multidimensional effects produced by the reuse/renovation interventions was developed, effectively testing the proposed evaluation framework.

The analysis of the indicators demonstrates that the Villa Vannucchi project has positive environmental, economic, and social impacts.

In environmental terms, satisfactory results were achieved. In fact, three project alternatives were evaluated and compared using the LCA to determine the one with the smallest environmental impact in terms of carbon emissions, the use of biomaterials, and alternative energy solutions, etc.

Regarding the social and cultural effects, it emerges that the local community positively receive and share the project, as demonstrated from the satisfactory score achieved by the indicators related to “social value thematic area”, including the perception of wellbeing, number of associations, volunteer cooperatives related to the functional reuse, place attachment and local identity, sense of place, and to the identification of the heritage value.

Regarding the economic aspect, the most positive impact produced is related to the costs incurred for the realization of the project, which will be amortised by future electricity savings incurred previously for heating/cooling the facility. The creation of new jobs can also be considered a substantial economic effect.

Furthermore, another significant piece of information deduced from the application of the CHL(s) evaluation framework refers to the state of conservation of the villa. The results shows that the actions identified in the Scenario C are “respectful” of building values, showing high performance in terms of recognizability and reversibility.

The achieved results show an integrated approach that distinguishes this case study from others in which Level(s), HIA, and GBC tools were utilised.

In fact, the case studies that referred to HIA (Liverpool, Stockholm bypass road, Cologne Cathedral in Germany, Gallery Lower in Australia, etc.) are based solely on the collection of data analyzed by expert knowledge. The good practices in which Level(s) has been applied (Finland, Spain, Slovenia, Croazia, Poland case studies and so on) do not take into account the social and cultural dimensions. Furthermore, GBC certifications focus exclusively on the measurement of environmental impacts (the Guinelli building in Ferrara, Meis in Ferrara, scuderie of S. Apollinare in Perugia, etc).

This study represents a contribution to research in this field because the proposed evaluation tool was developed with the intention of providing decision-makers with a tool to simultaneously assess economic, environmental, and socio-cultural impacts.

Concerning the limitations of the proposed evaluation framework, the required data referred to economic and environmental are often not easy to gather. Another limitation pertains to the data collected during the participation phase (the survey through the questionnaire): the number of respondents is limited and they do not always make an informed judgment at the time of survey submission (but can be influenced by external factors).

The difficulty related to economic and environmental data collection can be overcome by enhancing and implementing the BIM methodology, in particular through the potential offered by the Heritage BIM (HBIM). The application of BIM to existing heritage provides numerous opportunities to optimize the management, maintenance and preservation of built heritage [89].

In addition, by combining BIM with assessment tools, such as CHL(s), it allows for dynamic monitoring of the impacts of different design alternatives.

It is important to note that urban transformation involved not only the heritage registered to the world heritage lists, but also historical buildings and landscapes of state and regional significance, which are regulated and protected by local cultural heritage superintendencies (the Italian Ministry of Culture).

In this view, in the evaluation process of heritage projects included in the world lists, the interviewed sample have to be expanded and go beyond the local community. Thus, the evaluation should be carried out first at the local level, “creating a patchwork quilt of values and attitudes” [18] and then to the wider levels (such as the world one). Commonalities can be extracted to the state and ultimately to the national level.

6. Conclusions

A crucial step in the decision-making process is gaining an in-depth understanding of the building to be renovated in order to identify those design options that complement the building’s particular characteristics. This knowledge enables the identification of the building’s strengths and weaknesses so that design decisions can be oriented to maximize the former and minimize the latter.

In addition, an in-depth understanding of the building’s behaviour enables the identification of actions that improve its performance, thereby reducing negative environmental impacts over the building’s entire life cycle.

The proposed tool can be used to evaluate different project alternatives referring to the same building, taking into account multidimensional impacts that can be produced.

Incorporating the various dimensions, values, and attributes that characterise cultural heritage, this tool aims to overcome the sectorial limitations of officially recognised evaluation tools currently in use (Section 2).

Furthermore, the suggested integrated evaluation framework can be utilized at various stages of the decision-making process: ex ante, ongoing, and ex post.

Ex-ante evaluation provides early-stage strategic information about the main choices at an early stage of a project process [66]. LCA can be used as ex-ante evaluation tool for testing alternative interventions, putting claims of environmental sustainability to the test, and supporting early design improvements and sound investments [67]. However, this tool alone is insufficient on its own; it needs to be integrated with other evaluation tools that can capture the multidimensional impacts of projects (such as CHL(s)).

In contrast to the Level(s) tool, based only on expert knowledge, a strength of the proposed approach is the integration between the expert and common knowledge.

In fact, the data in the evaluation sheet refer both to technical data and data deduced from the community’s involvement (through the survey), which represents one of the project’s primary users/beneficiaries. The survey allows for the co-evaluating of the project’s impacts.

The evaluation framework has multiple receivers: the researchers and professionals responsible for developing such an analysis; the building’s users; the managers who finance the reuse project; the material suppliers; and the community who “live and transform” the building. Given the number of potential recipients and the specificity of the required data, it may be useful to invest in training courses to help users become more confident and aware when using this tool.

In addition, the drafting of guidelines to improve the clarity and accessibility of such a tool would be a significant step forward in the current research. The development of the aforementioned guidelines (as was done for the Level(s) tool) can support the management of the complexity and specificity of some of the data required by the evaluation framework, as well as their integration with other tools such as BIM. Integration with modelling tools that dynamically show, in real time, the variation of potential effects in response to varying design choices is a fruitful research area.

In conclusion, the future step of this research is to stress and implement the proposed evaluation framework in order to strengthen the relation between CHL(s) and HBIM design. Changes made on the BIM model can result, in real time, in the change of effects assessed in the CHL(s). The CHL(s) can “communicate” and interact with the HBIM, providing indicators referring to the fifth dimension of BIM (the economic dimension) and the sixth dimension (environmental dimension), that is, integrating the indicators currently existing in the HBIM. Furthermore, a new dimension could be included in reference to socio-cultural indicators.

Since the BIM methodology does not allow for the measuring of social and cultural effects, a future goal of related research would be to include the data that refers to the stakeholders’ perception in the BIM model.