Advancing Sustainability and Heritage Preservation Through a Novel Framework for the Adaptive Reuse of Mediterranean Earthen Houses

Abstract

Adaptive reuse of Mediterranean earthen houses offers a unique opportunity to fuse heritage preservation with sustainable development. This study introduces a comprehensive, sustainability-driven framework that reimagines these vernacular structures as culturally rooted and socially inclusive assets for contemporary living. Moving beyond conventional restoration, the proposed framework integrates environmental, socio-cultural, and economic sustainability across six core dimensions: ecological performance and material conservation, respectful functional transformation, structural resilience, cultural continuity and community engagement, adaptive flexibility, and long-term economic viability. Four geographically and culturally diverse case studies—Alhambra in Spain, Ghadames in Libya, the UCCTEA Chamber of Architects Main Building in North Cyprus, and Sheikh Hilal Beehive Houses in Syria—serve as testbeds to examine how earthen heritage can be reactivated in sustainable and context-sensitive ways. Through qualitative analysis, including architectural surveys, visual documentation, and secondary data, the study identifies both embedded sustainable qualities and persistent barriers, such as structural fragility, regulatory constraints, and socio-economic disconnects. By synthesizing theoretical knowledge with real-world applications, the proposed framework offers a replicable model for policymakers, architects, and conservationists aiming to bridge tradition and innovation. This research highlights adaptive reuse as a practical and impactful strategy for extending the life of heritage buildings, enhancing environmental performance, and supporting community-centered cultural regeneration across the Mediterranean region.

1. Introduction

Earthen architecture has long shaped the cultural and environmental fabric of the Mediterranean region [1,2]. Characterized by locally sourced materials, passive climate control, and deeply rooted spatial traditions [3,4,5,6,7], Mediterranean earthen houses represent both a sustainable building typology and a repository of intangible heritage. However, many of these structures face increasing threats from urbanization [7,8,9], climate change [10,11], neglect [11,12,13], and social instability [14,15]. In this context, adaptive reuse emerges as a powerful strategy to re-integrate such heritage into modern life while respecting its historical essence [3]. Yet, achieving this balance between preservation and modernization requires more than technical intervention—it demands a holistic, sustainability-oriented approach that addresses environmental, cultural, social, and economic dimensions [16].

Existing literature on adaptive reuse and heritage conservation emphasizes the significance of minimal intervention [17], material authenticity [18,19], and functional flexibility [3]. Sustainability has increasingly been recognized as a vital lens in heritage discourse, particularly concerning energy efficiency, resource conservation, and community resilience. Studies on earthen architecture, notably by Sanagustín-Fons et al. (2025) [20], and more recent works focused on climate adaptation, underline the inherent ecological advantages of earthen construction. However, few integrate these threads into a cohesive methodology that addresses the reuse of Mediterranean earthen heritage with sustainability as a guiding principle.

Despite a growing awareness of sustainability in heritage practices, significant gaps persist. First, most adaptive reuse frameworks remain overly focused on architectural or technical aspects, neglecting socio-cultural continuity and economic revitalization. Second, earthen heritage in the Mediterranean context is underrepresented in both theory and policy. Lastly, case-based insights often remain isolated, lacking a unifying framework that can be adapted across varying geographies and cultural narratives. There is a critical need for a systematic, multi-dimensional approach that bridges theory with grounded practice, while explicitly prioritizing sustainability.

This study aims to develop and validate a novel, sustainability-centered framework for the adaptive reuse of Mediterranean earthen houses. The framework integrates six core dimensions: ecological performance and material conservation, respectful functional transformation, structural resilience, cultural continuity and community engagement, adaptive flexibility, and economic viability. Four case studies—Alhambra (Spain), Ghadames (Libya), the UCCTEA Chamber of Architects Main Building (North Cyprus), and Sheikh Hilal Beehive Houses (Syria)—were selected to represent diverse architectural traditions and socio-political contexts within the Mediterranean basin. Data were collected through architectural documentation, photographic surveys, and secondary sources, analyzed using a comparative, qualitative approach. Based on the primary aim of this study, the central research question is formulated as follows: How can the adaptive reuse of Mediterranean earthen architecture be guided through a sustainability-based framework that effectively balances environmental performance, cultural integrity, and community relevance?

The authors contribute to the growing interdisciplinary discourse on sustainable heritage by introducing a robust and transferable framework for the adaptive reuse of earthen architecture. By situating this research at the intersection of sustainability science, architectural conservation, and vernacular studies, this work advances theoretical understanding while providing practical tools for architects, planners, and policymakers. Moreover, this study foregrounds Mediterranean earthen heritage as a valuable, yet underexplored, domain in global sustainability efforts, calling for its revalorization in contemporary urban and rural development.

1.1. Earthen Architecture

Earthen architecture refers to the construction of buildings using earth-based materials such as adobe, rammed earth, cob, and compressed earth blocks [21]. As one of the most ancient and widespread building traditions, it has been practiced for over 10,000 years and is particularly prevalent in arid and semi-arid regions, including the Mediterranean [22]. These structures reflect deep-rooted connections between human settlement, environmental conditions, and cultural identity. In the Mediterranean context, earthen houses are not only environmentally responsive but also integral to local heritage, showcasing climate-adaptive designs, vernacular knowledge, and communal spatial organization. Scholars such as Fuchs et al. (2024) [12] have highlighted the technical richness of earthen construction methods, while others like Mileto and Vegas López-Manzanares (2022) [23] and Manzano-Fernández et al. (2024) [10] emphasize their socio-cultural significance. From an environmental perspective, earthen buildings offer high thermal mass, low embodied energy, and full recyclability, aligning well with contemporary principles of sustainability and circular economy. They naturally regulate indoor temperatures, reduce the need for mechanical systems, and use locally sourced materials with minimal ecological impact. However, despite their benefits, earthen buildings often face neglect, negative perceptions, and a lack of integration into modern building codes and urban development strategies. In recent years, academic and professional interest in earthen architecture has resurged, driven by global concerns about climate change, affordable housing, and cultural preservation. Organizations such as CRAterre-EAG and international bodies like ICOMOS, ICCROM, and UNESCO have advocated for the protection and revitalization of earthen heritage, while contemporary research has explored innovative methods for structural reinforcement, seismic resilience, and hybrid design approaches [24]. Nevertheless, gaps remain in developing comprehensive frameworks that link the sustainable potential of earthen architecture with adaptive reuse, especially in Mediterranean contexts where political, environmental, and cultural dynamics intersect. As such, earthen architecture is increasingly recognized not only as a valuable heritage asset but also as a forward-looking model for sustainable, inclusive, and resilient built environments.

The lifecycle of earthen architecture follows a highly sustainable and circular process that begins with the local extraction of raw earth, typically sourced from nearby construction sites, riverbeds, or agricultural land. This phase involves minimal energy consumption and, when conducted responsibly, causes little to no environmental harm. In the preparation stage, the extracted soil is tested and combined with natural stabilizers such as straw, lime, or sand to improve its durability and strength. The prepared material is then formed into building elements—adobe blocks, rammed earth forms, or cob mixes—depending on the construction technique. The construction phase is typically carried out using traditional, labor-intensive methods that reflect local cultural practices and climate-responsive design, ensuring structures that offer passive thermal benefits and a low ecological footprint. During the use phase, earthen buildings provide excellent indoor environmental quality through natural regulation of temperature and humidity, contributing to energy efficiency and occupant well-being. Ongoing maintenance is straightforward, requiring periodic reapplication of earthen plaster, crack repairs, and moisture protection—usually achievable using local knowledge and materials. As buildings reach the end of their cycle, they can be deconstructed with little environmental disruption; their materials naturally biodegrade without contaminating soil or water. Finally, in the recycling phase, the earthen material can be rehydrated and reused in new construction or simply returned to the earth, completing a regenerative cycle. Importantly, as illustrated in Figure 1, adaptive reuse can be introduced as an intermediate phase before the end of the cycle, extending the building’s life, reducing the need for new materials, and preserving cultural and architectural heritage in a sustainable manner.

1.2. Sustainable Adaptive Reuse Framework for Mediterranean Earthen Houses

The concept of sustainable adaptive reuse has gained increasing traction in architectural and heritage discourses as a strategy for extending the life of buildings while aligning with environmental, cultural, and economic sustainability goals [25]. Adaptive reuse refers to the process of repurposing existing structures for new functions, ideally with minimal intervention and maximum respect for their original character and context [26]. When applied to earthen Mediterranean houses, this approach takes on added complexity and significance, as these buildings embody fragile material systems and deep-rooted cultural traditions. Earthen architecture in the Mediterranean region—such as beehive houses in Syria, adobe villages in North Africa, and rural earthen dwellings in Southern Europe—represents a synthesis of vernacular ingenuity, environmental responsiveness, and communal identity. However, these structures are often marginalized in contemporary planning frameworks and face multiple threats including abandonment, environmental degradation, modernization pressures, and regulatory neglect. The literature increasingly recognizes the need for sustainable reuse models that respect the embodied energy and cultural significance of earthen buildings while adapting them to current needs [3,18]. Sustainability in this context is multi-dimensional: environmental sustainability requires the conservation of low-impact materials and passive design features [27]; social sustainability calls for community involvement and cultural continuity [28]; and economic sustainability depends on viable new uses that support livelihoods and revitalization [29]. Scholars such as Manzano-Fernández et al. (2024) [10] and Khalil and Üzümcüoğlu (2025) [3] have argued that adaptive reuse strategies should not merely preserve form, but enable resilient, inclusive futures for historic buildings. Despite the growing body of work on sustainable reuse, there is a distinct lack of integrated frameworks that address the specific material, climatic, and socio-cultural conditions of Mediterranean earthen architecture. Moreover, earthen structures pose unique challenges for reuse—such as structural fragility, moisture sensitivity, and lack of compatibility with modern infrastructure—that require tailored technical and policy solutions. Recent studies advocate for the incorporation of sustainability metrics, participatory methods, and lifecycle assessments into adaptive reuse planning [24]. Yet, few models holistically merge these considerations within the Mediterranean context. As such, there is a pressing need to develop and apply a Sustainable Adaptive Reuse Scheme that bridges traditional knowledge with contemporary sustainability standards, ensuring that Mediterranean earthen heritage remains both relevant and resilient in the face of global change.

Figure 2 illustrates the combined model of Sustainable Adaptive Reuse for Mediterranean Earthen Houses, integrating core criteria from both vernacular earthen architecture and contemporary sustainability principles. Each of the six criteria that form the foundation of the theoretical framework for this study was carefully selected through an in-depth review of the interdisciplinary literature on sustainability, heritage conservation, vernacular architecture, and adaptive reuse. These criteria were not only chosen due to their prevalence and theoretical weight in academic discourse but also because they directly address the core concerns embedded in the adaptive reuse of Mediterranean earthen buildings. Their selection ensures a comprehensive lens through which the complexities of environmental, cultural, and social sustainability can be analyzed in heritage contexts.

The criterion of environmental sustainability and material efficiency emerged from the extensive literature on sustainable building practices, where scholars have consistently emphasized the use of local, low-impact materials, the reduction of embodied energy, and the necessity of circular material cycles in construction. Studies by Benghida (2016) [30], as well as Shahabadi et al. (2019) [31], highlight the ecological compatibility of earthen architecture and its role in promoting material regeneration. In parallel, passive design and thermal performance is a widely discussed concept in vernacular and bioclimatic architecture literature, particularly in relation to the Mediterranean’s hot-arid climate. Scholars such as Wang et al. (2023) [32] and Kinjawadekar (2019) [33] have shown that earthen buildings inherently offer climate-responsive features that contribute significantly to energy efficiency without the need for mechanical systems.

Another essential dimension, cultural and vernacular integrity, is deeply rooted in heritage conservation theory. The importance of maintaining spatial logic, traditional craftsmanship, and the intangible values embedded in architecture has been well-documented by Mileto and Vegas López-Manzanares (2022) [23] and Carlos et al. (2022) [34]. This criterion ensures that adaptive reuse strategies do not compromise the authenticity or identity of historic buildings. Closely related to this is functional adaptability and minimal intervention, which responds to debates in adaptive reuse literature regarding the need to preserve a building’s original character while allowing for new uses. Authors such as Sadeghi (2018) [35] and Iyer (2014) [36] emphasize reversibility, spatial flexibility, and non-invasive methods as essential to responsible reuse.

In addition to environmental and architectural concerns, the social dimension is addressed through the criterion of community engagement and social relevance. This reflects a growing consensus in sustainability and heritage discourse that adaptive reuse should be participatory and rooted in local needs and identities. The works of Frenda (2016) [37] and Lorenzon (2023) [38] underscore the value of community stewardship, not only for successful project outcomes but also for sustaining cultural continuity. Finally, longevity, maintenance, and lifecycle renewal incorporate perspectives from lifecycle analysis and vernacular resilience studies. Research by Fuchs et al. (2024) [12] and Gado et al. (2010) [39] demonstrates that earthen architecture is not only low impact during its construction and use phases but can also be naturally reintegrated into the environment or regenerated through simple, low-tech interventions.

Collectively, these six criteria provide a multidimensional response to this study’s central research question: How can the adaptive reuse of Mediterranean earthen architecture be guided through a sustainability-based framework that balances environmental performance, cultural integrity, and community relevance? Each criterion is conceptually linked to one or more aspects of this question. Environmental performance is directly addressed through environmental efficiency and passive thermal design; cultural integrity is evaluated through considerations of vernacular identity and minimal intervention; and community relevance is assessed via social engagement and the potential for lifecycle renewal. This conceptual structure ensures a smooth and logical transition from the theoretical framework to the empirical analysis of the case studies, enabling a holistic and evidence-based evaluation of adaptive reuse practices across diverse Mediterranean contexts.

2. Materials and Methods

This study employs a qualitative case study methodology to examine the sustainable adaptive reuse potential of Mediterranean earthen houses. The analytical framework, illustrated in Figure 2, serves as the foundational schema for evaluating the selected cases across six integrated dimensions: environmental sustainability and material efficiency; passive design and thermal performance; cultural and vernacular integrity; functional adaptability and minimal intervention; community engagement and social relevance; and longevity, maintenance, and lifecycle renewal.

This study focuses specifically on Mediterranean examples rather than global cases due to the region’s shared climatic conditions, socio-political complexities, and distinctive morphological characteristics. Mediterranean earthen architecture often reflects a deep interdependence between built form and climate-responsive design, particularly in response to arid and semi-arid environments. Moreover, many parts of the region face similar challenges, including political instability, economic constraints, and limited institutional support for heritage preservation—all of which impact adaptive reuse efforts. Architecturally, the Mediterranean basin presents a rich diversity of vernacular forms constructed with locally sourced materials and adapted to similar environmental and cultural contexts, making it a coherent and relevant field for comparative study.

The novelty of the proposed framework lies in its integration of environmental sustainability, vernacular integrity, and socio-cultural continuity within a unified, case-based evaluation model tailored specifically to earthen architecture in the Mediterranean context. While existing models often focus either on technical preservation, energy performance, or architectural heritage in isolation, this framework offers a multidimensional approach that bridges theory and practice. It not only draws from established sustainability and conservation principles but adapts them into six interrelated criteria that are tested across diverse real-world cases. This methodological structure enhances applicability, comparability, and transferability, offering a tool that can inform both policy development and on-the-ground interventions in similar heritage contexts.

The selection of the four case studies—Alhambra in Spain, Ghadames in Libya, UCCTEA Chamber of Architects Main Building in North Cyprus, and the Sheikh Hilal Beehive Houses in Syria—was guided by both conceptual relevance and practical feasibility, particularly in terms of data accessibility. These cases were deliberately chosen to represent a diverse geographical and cultural cross-section of the Mediterranean region, encompassing different climatic conditions, historical contexts, architectural typologies, and current usage scenarios. The Alhambra and Ghadames are internationally recognized UNESCO World Heritage Sites, offering rich documentation on conservation and visitor management, while the UCCTEA building exemplifies a successful institutional reuse of a residential earthen structure in a historically layered urban fabric. In contrast, the Sheikh Hilal Beehive Houses in Syria provide insight into rural, community-built vernacular forms that are at risk due to socio-political instability. Importantly, these cases were also selected due to the availability and accessibility of reliable data sources, including architectural documentation, photographic archives, and published research. Given the logistical and political challenges in accessing many earthen heritage sites across the Mediterranean, this set of case studies provided a unique combination of typological variety and data richness. This strategic selection not only ensured methodological consistency and empirical depth but also enabled a comparative analysis that is both regionally grounded and broadly applicable to other Mediterranean contexts facing similar sustainability and conservation challenges (

Table 1. Summary of the selected case studies, highlighting their locations, key features, and rationale for selection based on relevance and data accessibility.

Case Study	Location	Type/Function	Key Features	Rationale for Selection
Alhambra	Granada, Spain	Monumental/Historic Complex	UNESCO World Heritage Site; Moorish architecture; earthen structural elements; high tourism pressure	Represents large-scale, institutional heritage with extensive documentation and global conservation relevance
Ghadames	Ghadames, Libya	Historic Residential Urban Fabric	UNESCO World Heritage Site; traditional earthen houses; vernacular urbanism; located in desert climate	Offers insight into a cohesive earthen settlement; culturally and climatically significant; accessible literature and photographic resources
UCCTEA Chamber of Architects Main Building	Nicosia, North Cyprus	Residential turned Institutional Reuse	Early 20th-century adobe structure; located in historic walled city; currently reused as architectural HQ	A rare example of adaptive reuse of an earthen house into a functional public space; well-documented due to institutional affiliation and urban context
Sheikh Hilal Beehive Houses	Northern Syria	Rural Vernacular Housing	Unique conical adobe domes; climate-responsive; community-built; culturally symbolic but at risk	Demonstrates traditional earthen architecture under threat; selected due to its architectural uniqueness and available secondary data despite limited on-site access

).

For the data analysis, each case was systematically evaluated using the criteria outlined in Figure 2, allowing for a comparative understanding of how each structure addresses or falls short in relation to sustainable adaptive reuse principles. The analysis involved both descriptive assessment and interpretive synthesis, drawing on qualitative indicators within each dimension.

A key methodological limitation of this study is the absence of primary data collection through stakeholder interviews or field visits. Due to ongoing regional instability and restricted accessibility—particularly in areas affected by conflict or political tension—direct engagement with local communities, practitioners, or heritage authorities was not feasible. As a result, the research relied exclusively on secondary data sources, including published architectural documentation, photographic archives, and previously collected datasets. While these sources provided valuable insights for a comparative case-based analysis, the lack of on-site observations and stakeholder perspectives limits the depth of contextual understanding and may affect the nuance of local socio-cultural dynamics within each case. Future research incorporating fieldwork and participatory methods is recommended to complement and enrich the findings presented here.

Finally, the literature findings on earthen architecture and sustainable reuse principles were integrated with the case-based results to develop a refined understanding of challenges, opportunities, and strategic directions for the sustainable adaptive reuse of Mediterranean earthen houses. This combined approach ensures both theoretical depth and practical relevance in the study’s outcomes.

3. Findings

The selection of case studies in this research was guided by the objective of capturing a diverse and representative range of Mediterranean earthen architecture, emphasizing geographical distribution, architectural typology, and cultural significance. The chosen cases reflect varying historical backgrounds, functional uses, and levels of conservation and reuse, offering a broad basis for evaluating the proposed framework.

Key criteria included geographical diversity across the Mediterranean region to account for different climatic and cultural contexts; distinct architectural characteristics such as construction techniques, spatial configurations, and heritage value; and the availability of reliable documentation, including architectural drawings, photography, and historical or conservation datasets. Particular effort was made to select cases with varied adaptive reuse statuses, from preserved heritage monuments to modest vernacular settlements. The geographic distribution of the selected case studies across the Mediterranean region is depicted in Figure 3, highlighting their diverse locations and contextual variety.

However, the selection process faced limitations due to access restrictions in conflict-affected regions and inconsistencies in available documentation, particularly in areas like Libya and Syria. Despite these constraints, four representative case studies were selected: the Alhambra of Granada in Spain, a UNESCO World Heritage site and iconic example of monumental Islamic architecture; Ghadames in Libya, a well-preserved walled city known for its communal earthen housing and also recognized by UNESCO; the UCCTEA Chamber of Architects Main Building in North Cyprus, a former residence from the early 20th century now adaptively reused as an institutional facility within the walled city of Nicosia; and the Beehive Houses of Sheikh Hilal in Syria, a unique settlement of domed earthen structures that reflect vernacular design and have been listed as a UNESCO World Heritage site (Figure 3). Together, these cases provide a valuable cross-section of Mediterranean earthen architecture and allow for the comprehensive application of the sustainable adaptive reuse framework proposed in this study.

3.1. Case 1: Alhambra of Granada in Spain

Figure 4 presents the location of the Alhambra in Granada, Spain, offering spatial context for its inclusion as a representative case of monumental earthen heritage. The Alhambra of Granada stands as an exceptional example of adaptive reuse within a heritage context, embodying many of the principles of sustainable architecture and conservation (

Table 2. Evaluation of the Alhambra of Granada according to six criteria for the sustainable adaptive reuse of Mediterranean earthen houses (authors).

Satellite View of the Case Area

Plan

Evaluation of the Case Along with Six Criteria for the Sustainable Adaptive Reuse of Mediterranean Earthen Houses

1. Environmental sustainability and material efficiency are evident in the original construction, which employed locally sourced, low-impact materials such as rammed earth (tapial), lime plaster, and wood. While the site’s ongoing conservation adheres to preservation protocols rather than full lifecycle recycling, maintenance practices often prioritize traditional materials and techniques, aligning with sustainability goals. 2. Passive design and thermal performance are central to the Alhambra’s architectural genius. Its thick earthen walls, controlled fenestration, water features, and shaded courtyards create an effective passive cooling system well-suited to Granada’s semi-arid climate. Although modern energy interventions are limited due to conservation constraints, the original design continues to offer high environmental performance. 3. Cultural and vernacular integrity is rigorously preserved. The Alhambra remains a symbol of Andalusian–Islamic heritage, with restoration and reuse efforts guided by strict adherence to historical authenticity. Spatial organization, ornamental details, and construction methods are respected and carefully maintained, making it a reference for best practices in preserving cultural identity. 4. Functional adaptability and minimal intervention have been approached with great caution. While the Alhambra has not been radically repurposed, it has been adaptively reused as a public monument and museum complex. This reuse ensures public access and education without significant structural modifications, maintaining the integrity of the original layout and materials. 5. Community engagement and social relevance are reflected in the Alhambra’s strong role in Spanish cultural life and its visibility as a national symbol. Though community participation in conservation decisions may be limited due to its institutional governance, the site significantly contributes to local identity, education, tourism, and economic vitality, thereby reinforcing its social value. 6. Longevity, maintenance, and lifecycle renewal have been consistently addressed through systematic restoration programs dating back to the 19th century. Preventive conservation, routine monitoring, and ongoing research have allowed the Alhambra to remain structurally sound and culturally relevant, exemplifying a successful long-term preservation model that supports the resilience of earthen heritage.

).

3.2. Case 2: Ghadames in Libya

The historic walled settlement of Ghadames in Libya is situated in the regional map shown in Figure 5, emphasizing its climatic and cultural setting. Ghadames, often referred to as the “pearl of the desert”, is a prime example of sustainable vernacular architecture, reflecting centuries of adaptation to harsh Saharan conditions through earthen construction and communal living patterns (

Table 3. The evaluation of Ghadames in Libya based on the six sustainability criteria for adaptive reuse of Mediterranean earthen houses (authors).

Satellite View of the Case Area

Module    Typical Plans    Module Section    Group

Evaluation of the Case Along with Six Criteria for the Sustainable Adaptive Reuse of Mediterranean Earthen Houses

1. Environmental sustainability and material efficiency are deeply embedded in the construction of Ghadames. Built entirely from local materials—mud, lime, palm trunks, and gypsum—the city exemplifies low-impact, climate-responsive building. The traditional construction process follows circular lifecycle practices, where materials can be reused or reintegrated into the earth, aligning well with principles of environmental sustainability. 2. Passive design and thermal performance are among Ghadames’ most remarkable features. The architecture includes narrow, shaded alleyways, interconnected rooftops, and thick mud walls that provide exceptional insulation from extreme desert heat. The enclosed lower-level living spaces remain cool during the day and warm at night, requiring no mechanical heating or cooling, thus achieving outstanding passive performance. 3. Cultural and vernacular integrity is strongly preserved in Ghadames. The spatial organization—based on tribal divisions and a communal courtyard system—demonstrates deep-rooted social and religious traditions. Decorative motifs, traditional construction techniques, and gender-specific circulation patterns remain largely intact, contributing to the town’s exceptional cultural value, which earned it UNESCO World Heritage status. 4. Functional adaptability and minimal intervention are present but challenged. Although the historic core retains its structural integrity, many inhabitants have relocated to modern housing on the city’s outskirts, leading to underuse of the old city. However, occasional cultural festivals and tourism-related activities have introduced some adaptive reuse with limited intervention, though broader reuse potential remains largely untapped. 5. Community engagement and social relevance have historically been strong but have declined in recent decades. Ghadames was once a vibrant, self-sustaining community. While recent political instability and population shifts have reduced direct community involvement in conservation, ongoing interest from cultural organizations and heritage bodies suggests potential for renewed participatory initiatives. 6. Longevity, maintenance, and lifecycle renewal are challenged but not lost. The city has endured for centuries due to its maintenance-friendly materials and strong communal repair traditions. However, limited resources and urban migration have made ongoing maintenance more difficult. Despite this, the architectural logic and material systems still allow for renewal, positioning Ghadames as a powerful example of regenerative earthen architecture if supported by future revitalization efforts.

).

3.3. Case 3: UCCTEA Chamber of Architects Main Building in North Cyprus

The position of the UCCTEA Chamber of Architects Main Building within the historic urban core of Nicosia, North Cyprus, is shown in Figure 6, representing a successful example of adaptive reuse where a former early 20th-century residential earthen structure has been transformed into an institutional space, demonstrating the balance between preservation and contemporary function (

Table 4. Evaluation of the UCCTEA Chamber of Architects Main Building in North Cyprus using the six sustainable adaptive reuse criteria (authors).

Satellite View of the Case Area

Ground Floor Plan    First Floor Plan    Section    Elevation

Evaluation of the Case Along with Six Criteria for the Sustainable Adaptive Reuse of Mediterranean Earthen Houses

1. Environmental sustainability and material efficiency are apparent in the building’s original construction, which utilized locally available, low-impact materials such as adobe bricks, timber, and lime-based mortars. These traditional materials have a low carbon footprint and are consistent with circular lifecycle principles. During the adaptive reuse process, efforts were made to retain and repair these materials rather than replace them, preserving material efficiency and minimizing waste. 2. Passive design and thermal performance remain effective in the reused structure. The thick adobe walls and high ceilings offer natural insulation and thermal mass, buffering interior spaces from seasonal temperature fluctuations. Original elements such as wooden shutters and shaded verandas have been preserved or restored, enhancing the building’s passive cooling strategies without relying heavily on mechanical systems. 3. Cultural and vernacular integrity has been respectfully maintained through the adaptive reuse process. The building retains its original spatial configuration and architectural character, including façade elements, decorative woodwork, and layout, which reflect the early 20th-century Cypriot vernacular. By adapting it for institutional use while preserving these details, the project demonstrates a sensitive approach to heritage conservation. 4. Functional adaptability and minimal intervention are key strengths in this case. The building’s new function as the headquarters of the Chamber of Architects required only minor internal adjustments, which were made in a reversible and non-invasive manner. The flexibility of the original domestic layout supported its transformation into office and meeting spaces without altering its structural or aesthetic integrity. 5. Community engagement and social relevance are central to the building’s adaptive reuse narrative. As the home of the Chamber of Architects, the building serves not only as an office but also as a cultural and professional hub. It hosts exhibitions, public events, and architectural dialogues, strengthening its connection to the local community and reinforcing its identity within the urban fabric of Nicosia. 6. Longevity, maintenance, and lifecycle renewal are actively pursued through ongoing stewardship by the Chamber. The building is regularly maintained using traditional materials and techniques, ensuring its structural and aesthetic preservation. Its reuse for a professional purpose guarantees continual occupation, funding, and care—key factors in extending the life cycle of historic earthen structures.

).

3.4. Case 4: Beehive Houses in Syria

The rural location of the Beehive Houses in Sheikh Hilal, Syria is illustrated in Figure 7, underscoring their vernacular and community-based architectural context. These are an iconic form of vernacular earthen architecture, known for their unique conical shapes and efficient use of local materials. These structures embody centuries of ecological intelligence, cultural continuity, and community-centered construction practices (

Table 5. The evaluation of the Beehive Houses of Sheikh Hilal in Syria according to the six sustainable adaptive reuse criteria (authors).

Satellite View of the Case Area

Module    Typical Plan    Typical Section    Group

Evaluation of the Case Along with Six Criteria for the Sustainable Adaptive Reuse of Mediterranean Earthen Houses

1. Environmental sustainability and material efficiency are inherent in the design and construction of the beehive houses. Built entirely from sun-dried mud bricks and natural binders using earth sourced directly from the surrounding environment, these structures exemplify a circular building model. The materials are biodegradable, low-impact, and locally produced, requiring minimal processing and transportation. 2. Passive design and thermal performance are central to the success of the beehive typology. The domed geometry and thick mud walls provide excellent thermal mass, regulating indoor temperatures by retaining coolness during hot days and warmth during cooler nights. The buildings are naturally ventilated through small openings and strategically placed windows, eliminating the need for artificial climate control and contributing to high energy efficiency. 3. Cultural and vernacular integrity is deeply preserved in these houses. Their form, layout, and construction techniques are based on longstanding local traditions passed down through generations. The architectural typology reflects a deep connection to the socio-cultural and environmental context of the region, maintaining spatial logic, communal layouts, and construction rituals that reinforce their identity. 4. Functional adaptability and minimal intervention present both opportunities and challenges. While the original domestic function is well-preserved, modernization pressures and rural depopulation have led to abandonment or underuse in some areas. However, the inherent flexibility of the interior space allows for potential adaptive reuse with minimal structural changes—offering future potential for cultural, tourism, or educational uses if managed sensitively. 5. Community engagement and social relevance have historically been strong, with the houses constructed through collective labor and serving as expressions of local identity and resilience. However, recent socio-political conflict and displacement in Syria have disrupted traditional community networks and hindered participatory preservation. Efforts to reengage local communities and integrate these structures into future revitalization plans remain a critical need. 6. Longevity, maintenance, and lifecycle renewal are built into the architecture through simple, low-tech maintenance practices. The houses can be repaired using the same materials from which they were built, making upkeep affordable and accessible. When abandoned or no longer in use, the materials naturally degrade and return to the earth, completing the cycle and reinforcing the sustainability of the typology.

).

4. Discussion

The findings of this study affirm the growing body of literature emphasizing the intrinsic sustainability of earthen architecture and the importance of culturally sensitive adaptive reuse strategies. Previous research has consistently highlighted the ecological advantages of earthen materials, particularly their low embodied energy, thermal regulation properties, and compatibility with circular lifecycle models [3,24]. The evaluated case studies—Alhambra in Spain, Ghadames in Libya, UCCTEA Chamber of Architects in North Cyprus, and the Beehive Houses of Sheikh Hilal in Syria—provide practical confirmation of these attributes while also revealing context-specific challenges and opportunities in applying sustainable reuse principles.

The theoretical framework developed in this research was structured around six sustainability-oriented criteria: environmental sustainability and material efficiency; passive design and thermal performance; cultural and vernacular integrity; functional adaptability and minimal intervention; community engagement and social relevance; and longevity, maintenance, and lifecycle renewal. These dimensions synthesize insights from both sustainability discourse and heritage conservation theory, offering a comprehensive lens through which adaptive reuse can be assessed (Figure 2). When applied to the selected cases, the framework proved robust, capturing both the architectural and socio-cultural dynamics of each project.

Comparison with existing literature confirms the enduring value of passive design in earthen architecture, as seen in all four cases. The thermal comfort provided by thick adobe walls, high thermal mass, and climate-responsive layouts is well-documented in prior studies [4], and the case analyses reaffirm that these features remain effective and relevant, even in contemporary contexts. Particularly, the Beehive Houses and Ghadames demonstrate extraordinary climate performance with minimal energy input, while the Alhambra and UCCTEA, Chamber of Architects main building illustrate the preservation of passive systems within institutional and monumental reuse.

Cultural and vernacular integrity, as stressed in literature on intangible heritage and place identity [40], emerged as a pivotal consideration in all four cases. The Alhambra and Ghadames exemplify high levels of heritage authenticity, protected by institutional frameworks and conservation policies. In contrast, the Beehive Houses and the UCCTEA, Chamber of Architects main building reveal the impact of community and professional stewardship on sustaining cultural values, even in the absence of large-scale policy support.

The literature often identifies tension between modernization pressures and the preservation of heritage integrity [41]. This study finds that functional adaptability is achievable without compromising structural authenticity, especially when reuse strategies follow the principles of minimal intervention and reversibility. The UCCTEA, Chamber of Architects main building is a clear example of how institutional reuse can be achieved with minimal alteration, providing a model for context-sensitive transformation.

However, this study also uncovers critical gaps between theory and practice. While the literature promotes community participation and co-management as pillars of sustainable reuse [42], this was inconsistently realized across the cases. Ghadames and the Beehive Houses, for instance, suffer from weakened community involvement due to migration and conflict. These limitations underscore the need for inclusive planning processes and capacity-building initiatives that reconnect communities with their architectural heritage.

In terms of lifecycle renewal, the theory suggests that earthen buildings can be perpetually maintained and even reabsorbed by the earth in a regenerative cycle. Case findings support this, especially in the Beehive Houses and Ghadames, where local materials and techniques allow for ongoing renewal. Nevertheless, political instability, lack of funding, and absence of structured policy frameworks hinder long-term resilience, a concern echoed in broader literature on heritage in conflict zones [43].

In summary, this discussion highlights both alignment and dissonance between theoretical aspirations and real-world applications. While Mediterranean earthen architecture inherently aligns with sustainable principles, the effectiveness of adaptive reuse depends heavily on socio-political context, institutional support, and community engagement. The proposed framework not only synthesizes academic discourse but also offers a practical tool to assess and guide sustainable reuse in varied contexts (

Table 6. A comparative evaluation of all four case studies based on the six criteria for the sustainable adaptive reuse of Mediterranean earthen houses (authors).

Criteria	Alhambra (Spain)	Ghadames (Libya)	UCCTEA Chamber of Architecture Building (North Cyprus)	Beehive Houses (Syria)
1. Environmental Sustainability and Material Efficiency	Partially retained; stone and earthen elements preserved, but new materials introduced	Strong alignment; built with entirely local earth; minimal environmental impact	Good retention of adobe and traditional materials; minor use of modern reinforcements	Fully aligned; built entirely with local mud brick and natural binders
2. Passive Design and Thermal Performance	Historically strong; passive features remain but not actively enhanced in reuse	Excellent thermal regulation due to compact layout and thick walls	Maintains passive qualities with some supportive modern enhancements	Excellent; conical form offers superior ventilation and thermal comfort
3. Cultural and Vernacular Integrity	High preservation of symbolic and historic elements; strong heritage protection	Well-preserved vernacular forms and urban layout; culturally embedded	Maintains original architectural character and domestic logic through sensitive reuse	Strong integrity; authentic craftsmanship and spatial forms preserved
4. Functional Adaptability and Minimal Intervention	Limited adaptability due to monumental status; significant structural interventions	Low intervention but limited reuse; mostly abandoned	Highly adaptable; converted to institutional use with minimal structural change	Adaptable interior, yet underutilized and lacking structured reuse
5. Community Engagement and Social Relevance	Low community involvement; managed primarily by state and tourism bodies	Historically community-driven, but currently low engagement due to displacement	Moderate engagement via professional community; not broadly participatory	Historically strong social ties; current instability weakens community involvement
6. Longevity, Maintenance, and Lifecycle Renewal	High institutional maintenance; lifecycle extended through heritage tourism	Ongoing degradation; limited maintenance due to conflict and neglect	Maintained periodically by the institution; good renewal practices in place	Naturally renewable materials, but lack of formal maintenance endangers longevity

).

5. Conclusions and Suggestions

This study set out to explore how sustainable adaptive reuse can be effectively applied to Mediterranean earthen architecture by developing and applying a comprehensive theoretical framework grounded in sustainability, heritage preservation, and community engagement. By evaluating four diverse case studies—Alhambra in Spain, Ghadames in Libya, UCCTEA Chamber of Architects in North Cyprus, and Sheikh Hilal Beehive Houses in Syria—this research has illuminated the potential and challenges of reactivating traditional earthen buildings in a contemporary context.

This study demonstrates that adaptive reuse of Mediterranean earthen architecture can be effectively guided through a holistic, sustainability-based framework that integrates environmental efficiency, passive performance, cultural continuity, and community engagement. By applying this model to four diverse case studies, we show that such an approach not only extends the life of earthen buildings but also supports regenerative, culturally rooted, and climate-adaptive reuse practices. The central finding of the study reveals that Mediterranean earthen houses inherently embody sustainable principles, particularly in terms of material efficiency, passive design, and cultural continuity. However, adaptive reuse outcomes vary significantly depending on social, political, and institutional conditions. While some cases, such as the UCCTEA Chamber of Architects main building, demonstrate how minimal intervention and stakeholder engagement can lead to successful reuse, others, like the Beehive Houses and Ghadames, highlight the fragility of heritage in the absence of community empowerment and policy support.

The theoretical framework, structured around six integrated criteria—environmental sustainability, passive performance, cultural integrity, functional adaptability, social relevance, and lifecycle renewal—proved to be a valuable analytical tool for both assessing existing practices and guiding future interventions. This model can be adapted and applied by researchers, conservation professionals, and policymakers to evaluate and plan sustainable adaptive reuse projects across similar contexts.

In terms of practical recommendations, researchers are encouraged to pursue further interdisciplinary studies that deepen the integration of sustainability science, heritage conservation, and vernacular architecture. Future research should prioritize the development of lifecycle assessment models tailored to earthen buildings, focusing on low-tech, regenerative materials, carbon footprint reduction, and resource circularity. There is also strong value in incorporating digital tools such as GIS-based documentation, thermal imaging, and material performance simulation to support evidence-based decision-making in heritage reuse strategies. To strengthen the knowledge base, future research should also aim to broaden the geographic scope of case studies, incorporating lesser-known, recently restored, or community-led adaptive reuse projects, particularly in underrepresented rural and peri-urban areas. This would help diversify the typological and cultural variations within the Mediterranean earthen architecture corpus and better inform adaptable reuse models.

For decision-makers and urban planners, it is critical to promote adaptive reuse policies that prioritize minimal, reversible interventions, consistent with international charters such as the Venice Charter and the ICOMOS Principles for Sustainable Conservation [44,45]. Policies should include technical guidelines and measurable indicators to evaluate reuse projects—such as percentage of original material retained, embodied energy saved, reversibility of interventions, and level of local labor and traditional skill integration. These guidelines can help establish a baseline for sustainability performance and cultural integrity. Furthermore, economic instruments—such as restoration grants, tax incentives, low-interest heritage loans, and zoning bonuses—should be designed to support private owners, small cooperatives, and local NGOs engaged in adaptive reuse of heritage buildings. These tools should be tied to performance benchmarks to ensure responsible and culturally sensitive restoration practices.

For heritage conservation authorities, it is recommended to adopt participatory planning frameworks that actively engage local communities in the identification, implementation, and monitoring of adaptive reuse initiatives. Co-design workshops, community heritage mapping, and stakeholder feedback mechanisms should become standard elements in policy development. In parallel, the creation of region-specific technical manuals, certification programs, and apprenticeships can ensure that local builders, craftspeople, and young professionals are equipped with the knowledge and skills necessary to work with traditional earthen materials and construction methods while applying them through a sustainability lens. International organizations, donors, and cultural protection agencies should be urged to provide long-term financial and technical support for earthen heritage sites in conflict-affected regions such as Syria and Libya, where cultural assets face acute risks. Support should include not only emergency protection measures but also capacity-building programs, transnational knowledge exchange platforms, and pilot projects that serve as scalable models for post-conflict heritage regeneration. In this regard, partnerships among Mediterranean countries with shared climatic and architectural traditions can foster stronger regional collaboration and knowledge transfer. Finally, while the framework proposed in this study is specifically tailored to the Mediterranean context, its underlying structure—balancing environmental sustainability, vernacular integrity, and social relevance—offers a transferable model that could be adapted to other regions with similar climatic challenges, cultural heritage pressures, and resource limitations. For instance, parts of Sub-Saharan Africa, the Middle East, Central Asia, and Latin America share vernacular earthen construction traditions and could benefit from a contextualized adaptation of the six-criteria model. In these regions, further research would be needed to calibrate the framework to local governance structures, community engagement models, and material practices.

Data availability—especially for sites in conflict zones—posed challenges to comprehensive on-site analysis. The application of the framework also remains largely qualitative; future research may integrate quantitative performance metrics to enhance comparative analysis.

Ultimately, this study underscores that the sustainable adaptive reuse of earthen architecture is not merely a technical endeavor but a deeply cultural and ecological act. The proposed model bridges theory with practice, offering a path forward for the reintegration of traditional knowledge into modern sustainability agendas. By valuing the environmental intelligence and cultural depth embedded in Mediterranean earthen houses, stakeholders can turn heritage conservation into a proactive, regenerative force for both people and places.