Characterizing Sustainability and Assessing Biophilic Design in Vernacular Architecture: Case of Kasbahs and Ksour in South of Morocco

Abstract

In recent decades, sustainability and biophilic design have gained significant attention as revived concepts in architecture, offering innovative pathways to reconnect the built environment with nature. Can these principles be characterized and assessed in vernacular architectural contexts so as to be incorporated into contemporary sustainable practices? This research seeks to answer this question by examining the vernacular architecture of Kasbahs and Ksour in southern Morocco through the lens of biophilic design. The link between the two remains underexplored, specifically in the context of southern Morocco—a gap this article seeks to address. This research analyzes these heritage architectures by combining a theoretical exploration of sustainability, biophilic design (BD), and operational BD frameworks with a practical evaluation using a Biophilic Interior Design Matrix. This analysis is particularly pertinent as the contemporary society spends roughly 90% of its time indoors and is considered to be an “indoor generation”. After examining eleven vernacular buildings spread over key areas of Ouarzazate Province in southern Morocco against 54 biophilic design attributes, the findings reveal that Kasbahs and Ksour showcase sustainability and biophilic qualities. This demonstrates that Moroccan traditional architectural values can enable heritage preservation through biophilic principles to deliver culturally contextual and sustainable architectural solutions for contemporary practice.

1. Introduction

Kasbahs and Ksour in the south of Morocco are an intriguing architectural matter for research and exploration going back several centuries. Whereas Kasbahs are fortified houses or citadels typically serving as the homes of local leaders or military strongholds, the Ksour (plural of Ksar) are fortified villages and settlements often characterized by a compact urban layout with narrow winding streets and linked buildings. This earth architecture is often found on the slopes and valleys of the Atlas mountains and along the oases lines of the Pre-Saharan rivers. This research endeavors to study how these vernacular architectures intrinsically embody biophilic principles through their use of local, natural materials and harmonious integration with the surrounding landscape, reflecting a connection with nature. Their design, adapted to the climate, further demonstrates an inherent biophilia, creating life-enhancing spaces that resonate with the natural environment. These structures stand as an example of early biophilic design, where the built environment is in synergy with the natural world.

Despite biophilic design gaining prominence in architecture and urban planning globally and being aligned with international frameworks, particularly the 2030 Agenda for Sustainable Development, which highlights resilient, inclusive, and sustainable cities as the basis for sustainable urban development for all, there is still a need to identify how urban planners and architects incorporate biophilic design in their work to achieve sustainable goals. Robin Degron emphasizes that understanding the interconnectedness of time, civilization, and biodiversity is essential for addressing the environmental challenges faced by regions like the Mediterranean [1]. This approach not only underscores the fragility of Mediterranean ecosystems but also advocates for multi-disciplinary strategies that integrate insights from geology, ecology, and history to foster resilience against climate change. Biophilic design’s integration into architecture and urban planning can be a relevant instrument in this regard to improve sustainability initiatives, therefore ensuring that cities not only meet human needs but also assist the complex web of life-sustaining biodiversity and preserve the ecological balance essential for human existence [2]. Urban environments, when designed with biophilic principles, can help mitigate the impacts of climate change, such as rising temperatures and disappearing green spaces, thereby aligning with broader efforts to preserve the socio-ecological fabric of the Mediterranean region and beyond.

The design approach known as biophilic design draws its foundation from biophilia which means nature’s love fostering environmental connections. The concept gained traction after psychologist Erich Fromm first introduced it in 1964 before biologist Edward O. Wilson expanded its popularity in 1984 [3,4]. The implementation of biophilia principles through architectural and urban planning practices results in an environmental design that allows people to connect with nature directly or indirectly while improving their built environment quality. By integrating natural elements and processes into the design, biophilic architecture endeavors to restore the connection between people and their surroundings, positioning nature as a vital component in creating healthier, more sustainable living spaces [5,6].

In the past decade, biophilic design has garnered more research interest, as noted by Lefosse et al. According to the latter, their 60-year systematic literature review revealed that biophilia is an underexplored field with both opportunities and challenges, highlighting a gap between theory and practice, with more emphasis on the theoretical aspects. Basic research dominates over evidence-based research. Research on Biophilic Urbanism (BU) remains scarce despite rising interest in biophilia and biophilic design (BD) during recent times. The majority of written works focus on historical context because both fields emerged recently, while scientific studies are scarce. Applied and hybrid sciences show rising interest in biophilia while political–economic and digital science gaps persist. Geographically, the literature is predominantly northern, especially from the United States, the concept’s birthplace [7].

The idea of integrating nature into living spaces can be traced back to the earliest human settlements. Over the years, many different societies have welcomed the natural world as a source of motivation for their architectural projects. The architectural styles of ancient civilizations such as the Romans, Mesopotamians, and those of the Byzantine, Gothic, and Renaissance periods all show nature-themed patterns, providing evidence of this biophilic link. The Romans, for instance, utilized natural materials and integrated gardens and natural landscapes into their urban planning, which can be seen in the design of villas and public spaces [8,9]. The Mesopotamians, likewise, expressed their respect for nature by designing lavish garden spaces, such as the famous Hanging Gardens of Babylon, which were not only a symbol of royal opulence but also a manifestation of the belief in paradise as a cultivated space that harmonized human life with the forces of nature [10]. The architectural style of the Byzantine era showed its connection to natural surroundings balancing compositions of light and space [11]. During the Gothic period, sacred places gained spirituality through the use of large stained glass windows, which let sunlight enter to link interiors with exterior environments [12]. Brunelleschi and Palladio, during the Renaissance period, reintroduced classical principles by using symmetry and proportion in their architectural designs, which drew biosphere inspiration to create architecture that had an aesthetic dimension and impacted human emotions [13]. Modern architecture continued this tendency by adding natural elements into built environments, hence promoting well-being, as biophilic design concepts were becoming more and more recognized for their psychological and physiological benefits [14]. Because people inherently feel pulled to nature, the architectural design profession has used biophilia as a basic precept since Edward O. Wilson introduced this concept. Contemporary research [15,16,17] emphasizing the need to include natural components in architectural practices shows that this tendency is not just aesthetic but also affects health and well-being. Biophilia has shown throughout time how local materials and organic ornaments were essential to building techniques, thus highlighting humanity’s natural bond with the environment. The revival of biophilic design in contemporary architecture shows a rising awareness of the need to reconnect with nature, especially in cities where such links have grown more uncommon [18,19]. Modern developed surroundings often separate people from natural components including sunlight, flora, and fresh air, as industrialization and urbanization have caused a rift between people and nature in modern civilization. Research indicates that exposure to nature promotes health benefits, improves social interactions, and reduces stress [14]; therefore, this disconnection has major consequences for human well-being. Emerging as a framework for design to link people back to their natural environment, the concept of biophilia encompasses the basic human love for other life forms.

As a means to restore nature in urban settings, biophilic design (BD) has attracted interest in architectural theory. It includes ideas and components meant to strengthen human–nature relationships. Both academics and practitioners have created several frameworks to assist in using biophilic concepts in both “modern” and historical buildings. Whether by using natural materials, integrating plants, or adding natural light and water features, these frameworks promote the inclusion of biological elements, hence improving the sensory experiences of users.

The evidence-based assessment of biophilic design allows for shifting towards more sustainable architectural solutions in the Middle East and North Africa (MENA) region. Through the study and assessment of biophilic design in vernacular architecture, this research can help bridge the gap between Western discourses, practices, and regional experiences, thus questioning the latter beyond the efficiency paradigm.

This study provides insights on how the vernacular architecture of Kasbahs and Ksour in the south of Morocco aligns with biophilic design. The objectives of this research are to investigate the extent to which sustainability and biophilic design are inherent within these traditional architectural settings using the Biophilic Interior Design Matrix (BID-M) and to demonstrate the connection to nature and the integration of traditional ecological knowledge exhibited in these architectures.

The paper is articulated as follows: The relevant literature on biophilia, biophilic design (BD), and the sustainability of the vernacular architecture of Kasbahs and Ksour, as well as BD frameworks is reviewed in the next section. The methodology section then explains the research context, materials, and methods used in this study. For this research, eleven vernacular buildings from key localities in southern Morocco, representing Kasbahs and Ksour, were analyzed. These buildings were assessed using a Biophilic Interior Design Matrix (BID-M) consisting of 54 biophilic attributes distributed among six categories to understand the link between biophilic design and the vernacular architecture of the region. Next are the findings and discussion. The final section presents the conclusions and recommendations based on the study results and the literature review. This research provides new perspectives into integrating Moroccan traditional architecture with local contemporary sustainable practices, thereby highlighting the underexplored connection between biophilic design and these architectures.

2. Literature Review

Biophilia stems from the Greek words “bios” (βίος, “life”) and “philia” (φιλία, “love”), hence, meaning the “love for life”. “Philia” as a broader concept can be traced back to the philosophical ideas of Aristotle in the 4th century BC which pertains to interspecies relationships, suggesting that such connections are fundamental to the social, political, and moral frameworks of human interactions [20]. However, the specific term “biophilia” was introduced by the socio-psychologist Erich Fromm in 1964. Fromm’s research sought to emphasize the natural human desire to nurture and defend life. Emphasizing its relevance across many species, he contended that this desire for life is necessary for both individual and social well-being. Biologist Edward O. Wilson, who popularized the concept and incorporated it in his book, “Biophilia”, further developed the notion. Wilson called this natural love a fundamental human instinct rooted in biology. He stated that human inclination is meant for living in close contact with natural settings. Our human evolution is driven by this innate predisposition towards natural environments and living beings [4].

Historically, the link between people and nature has greatly affected where groups decide to settle, hence the balancing issues of safety and aesthetic appeal [21]. This quest for an optimal living environment emphasizes the need for biophilia in shaping human habitat and well-being. Contemporary studies emphasize how including natural components in architectural and urban designs would improve psychological well-being [22], highlighting the consequences of biophilia. For example, research has shown that biophilic design-rich settings boost cognitive performance and promote more productivity.

This discourse on human’s innate connection to nature underlines a constant need that has developed to fit manufactured environments to guarantee both survival and identity. This view supports the development of the biophilia hypothesis and its practical expressions. Years later, Kellert advanced the biophilia hypothesis by introducing the concept of biophilic design (BD), which sought to transform architectural practices. BD aims to enhance human interaction with nature even within indoor settings by integrating Engineering and Landscape Design [12]. Indeed, today, approximately 90% of individuals’ time is now spent indoors [23]. As a result, recent research consistently refers to contemporary populations as belonging to the “indoor generation”, highlighting a significant shift in daily living environments toward predominantly enclosed spaces.

This approach to biophilic indoor spaces exceeds conventional sustainable architecture by making buildings into living systems that help their occupants while optimizing their performance and human experience. In addition, the concept was taken to a larger scale by Beatley with the development of Biophilic Urbanism (BU) [24]. BU combines the principles of sustainable urban design and ecological management across different scales to develop environments that integrate natural elements into the urban environment. In his framework of Biophilic Cities, Beatley defines cities as those that integrate nature into the urban environment to allow people to regularly interact with nature. His concepts include several definitions of Biophilic Cities that include numerous advantages, including health benefits and the conservation of biodiversity. Also, the Biophilic Cities Network was developed by Beatley to promote the use of these approaches. In the course of these developments, there is an understanding of a shortcoming—the absence of a clear definition of biophilia that would encompass all its advantages [7]. To address this, an enriched perspective is proposed by Lefosse et al., defining biophilia as an enriching interaction with nature, through both sensory and emotional experiences, that yields reciprocal benefits in the built environment when implemented via biophilic design and Urbanism. This perspective emphasizes the goal of improving the human experience by means of deliberate design interlaced with nature.

Vernacular architecture is an eloquent example of sustainable design as it is defined by its alignment with local environmental settings, cultural practices, and accessible materials. Its dependence on locally sourced materials and traditional building techniques, which have usually evolved through years of empirical knowledge and cultural practices, makes this architectural form naturally sustainable. For instance, Alelwani et al. emphasize that vernacular architecture harmonizes with the surrounding environment while addressing the needs of its occupants, thus exemplifying sustainable building practices [25]. Similarly, Dabaieh et al. stated that vernacular architecture is built for local needs and with local resources, thus reflecting culture and history and promoting sustainability [26]. Moroccan Kasbahs and Ksour show a strong link between traditional construction and sustainability. The principles within these buildings can be analyzed through environmental, economic, and social sustainability lenses to understand their relevance in the contemporary architectural discourse.

First, the environmental sustainability of Kasbahs and Ksour is clear in their use of local materials and construction adapted to southern Morocco’s arid climate. For instance, these structures are mainly built from earth, stone, and other natural materials providing insulation and enhancing thermal comfort. Piqueras and Navarro noted that these vernacular architectures are sustainable because Kasbahs and Ksour use readily available environmental materials, showing environmental awareness and climate adaptation [27]. This is in concordance with the findings of Rosaleny-Gamón who noted that vernacular architecture offers valuable lessons in sustainability, especially in the way it addresses environmental issues through local know-how and practices [28].

In terms of economic aspects, the sustainability of Kasbahs and Ksour lies in the fact that they employ local resources and labor, which is financially stimulating the community. In fact, economically, it does not only create employment for the local population but also decreases reliance on external resources that may be unreliable or unsustainable [26].

Social sustainability is another key aspect. Kasbahs and Ksour are built and arranged to support the community’s social order and enhance people’s sense of belonging. The architecture is often planned to allow social contact and common activities, important for preserving cultural heritage and social capital. In their study on social sustainability in vernacular architecture, Olukoya and Atanda identified health, safety, and cultural values as key to communal resilience [29]. This is especially relevant for Moroccan Kasbahs and Ksour, where collective living and shared spaces are integral to the social structure. Historically and culturally, the architecture of these settlements reflects the region’s society. As noted by Hu, vernacular architecture is closely related to local knowledge and cultural identity [30].

Applications of biophilic design (BD) span a wide spectrum of scales, from the intimate spaces of building interiors to the broader context of city-wide developments, encompassing diverse environments such as university campuses, commercial office buildings, healthcare facilities, hospitals, and educational institutions. At its heart, BD seeks to fundamentally reshape design and construction with the central objective of forging a meaningful connection between human beings and the natural world. This design philosophy directly addresses the growing sense of alienation from nature that characterizes modern industrialized life, particularly in urban settings [12,31]. Ultimately, BD strives to enhance overall well-being by integrating natural elements and principles into the spaces we inhabit.

Biophilic design’s main objectives are as follows: First, BD aims at building sustainable and flourishing habitats that meet not only human expectations but also the needs of nature and a wide range of living species. This calls for a comprehensive strategy for urban development taking into account the environmental effects of buildings and infrastructure. Secondly, BD strives to actively promote and enable environments, events, and design processes that support interspecies contact [12]. The goal is to create connections that are good for both people and other living species, therefore improving living conditions for all. Thirdly, BD actively challenges and tries to correct the intrinsic flaws of modern design paradigms that have unwittingly isolated and alienated humans from their natural surroundings. Finally, and perhaps most importantly, BD is focused on highlighting and realizing the benefits of intentionally and thoughtfully applying the principles of Biophilia to the built environment. This includes recognizing and leveraging the innate human affinity for nature to create spaces that are not only aesthetical but also contribute to improved physical health, psychological well-being, and cognitive function [9].

The theoretical underpinnings of BD are not static but have evolved through a series of key developmental stages. This evolution is marked by the creation of various frameworks, tools, and conceptual approaches, each building upon and refining previous iterations. A foundational figure in this evolution is Stephen Kellert, widely regarded as a pioneer of biophilic design. Kellert’s initial and comprehensive framework proposed a systematic approach to BD, structured around two primary dimensions, six core elements, and an extensive list of 72 detailed attributes [31]. The two dimensions of natural and cultural form exist as fundamental elements because they determine how people perceive themselves in built structures. The first dimension, naturalistic or organic, focuses on design aspects that reflect natural elements. Natural features of the environment include natural lighting and ventilation systems along with botanical designs and biomimetic strategies and the integration of natural patterns that showcase sensory diversity and interactive organic systems. The second dimension, the place-based or vernacular, connects design to a place’s specific context. This involves light and space configurations creating a sense of place and evoking natural experiences, place-based relationships integrating local ecological and cultural characteristics, and evolved human–nature relationships acknowledging deep-seated human connections with nature through elements evoking prospect, refuge, and spatial organization.

Browning et al. built upon Kellert’s work by simplifying the approach and focusing on user well-being by categorizing space–nature interrelations into “nature in the space” (directly incorporating elements like plants and water), “natural analogs” (using nature-mimicking materials and patterns), and “nature of the space” (emphasizing spatial configurations found in nature) [32]. Kellert and Calabrese later developed it to focus on human perception and experience, identifying three experiential categories. Nature contact as direct experience enables the physical perception of water, air, and sunlight along with plants [33]. The indirect experience and exposition of nature stimulate nature’s feeling through the utilization of colors, materials, and patterns. The experience of space and place investigates how spatial attributes modify user responses regarding mobility, prospect, and refuge.

The Biophilic Interior Design Matrix (BID-M) represents one of the specialized frameworks that has been developed for interior spaces [34]. The BID-M emerged from the Biophilic Design Matrix (BDM) [35] to serve as a practical tool that includes six elements and 54 attributes for indoor biophilic implementation. New hybrid frameworks combine digital and physical design methods to deliver expanded biophilic experiences in residential and virtual reality applications across various building scales. Qualitative frameworks blend BD with green building standards LEED (Leadership in Energy and Environmental Design) and BREEAM (Building Research Establishment Environmental Assessment Method) to produce healthier sustainable design [36]. The classification of biophilic buildings shows how architectural design elements influence the creation of biophilic environments that support human–nature interactions. The different frameworks and tools illustrate how biophilic design has grown as a discipline and its applications have become more specific across various design fields, including residential and educational structures and special settings, while demonstrating its power to design environments that support human health as well as nature’s connection.

3. Materials and Methods

3.1. Research Context and Site Analysis

The architecture of Kasbahs and Ksour in Ouarzazate Province, Morocco, (see Figure 1) significantly reflects the region’s historical, cultural, and environmental contexts. It is influenced by the harsh desert climate, necessitating adaptations that promote sustainability and resilience against environmental challenges [37]. The geographical context of the Ouarzazate Province, located on the edge of the Sahara Desert, influences the architectural features of Kasbahs and Ksour. The region’s climate, marked by severe temperatures and limited water, shaped construction using rammed earth, adobe, and stone, among others. These materials and techniques offer thermal insulation and complement the surrounding scenery, creating a visually consistent atmosphere. Drawing on historical experiences and social systems, the forms are based on the cultural legacy of the Amazigh and Arab cultures [38].

Culturally, the Ksour serve as vital centers for community life, encapsulating the social organization and collective identity of the inhabitants. The architectural design of these settlements is also influenced by Islamic principles, which emphasize harmony with nature and the importance of solidarity [39]. This cultural significance is underscored by the Ksour’s national and international classification—Ksar Aït Ben Haddou, for example, has been a recognized UNESCO World Heritage Site since 1987.

Moreover, their preservation is threatened by ongoing changes driven by tourism and modernity. Growing tourism increases the risk of commodification and authenticity loss, potentially compromising the Ksour’s intangible value [40,41]. Maintaining the integrity of these structures implies balancing tourism needs with cultural heritage conservation.

3.2. Materials

Eleven buildings were selected. Access to functional and non-ruined spaces—either in total or partially—guided our research. See Figure 2 for a diagram of their repartition.

In fact, the selection process was guided by the availability of spaces that were mainly functional and/or partially intact, as opposed to ruined or non-functional structures. This approach ensured that the research could focus on living environments that reflect the practical application of biophilic design principles and that could be replicated elsewhere within both the local and global regions. See Figure 3 for their localization and

Table 1. Detailed list of analyzed vernacular buildings in Ouarzazate Province, south of Morocco.

N°	Locality	Vernacular Building	GPS Coordinates
1	Ksar Aït Benhaddou	Kasbah Tebi	31.0476° N, 7.1288° W
2	Ksar Aït Benhaddou	Kasbah Ait Ougram	31.0476° N, 7.1288° W
3	Ksar Aït Benhaddou	Kasbah El Hajja (Guest House)	31.0477° N, 7.1289° W
4	Ksar Aït Benhaddou	Dar Amghar—Tigmmi N Wawal/House of Orality	31.0475° N, 7.1287° W
5	Ksar Aït Benhaddou	Tiwirga House	31.0471° N, 7.1287° W
6	Ouarzazate	Ksar Taourirt: Kasbah Taourirt —Small House 1 at East part “Stara”	30.9189° N, 6.9094° W
7	Ouarzazate	Ksar Taourirt: Kasbah Taourirt— Medium House 2 at East part “Stara”	30.9187° N, 6.9092° W
8	Ouarzazate	Ksar Taourirt: Kasbah Taourirt— Large House 3 at East part “Stara”	30.9185° N, 6.9090° W
9	Ouarzazate periphery (9 km to Ouarzazate)	Kasbah Tifoultoute	30.9333° N, 6.9833° W
10	Skoura	Kasbah Amridil	31.0466° N, 6.5660° W
11	Skoura	Kasbah Ait Ben Moro	31.0468° N, 6.5662° W

for full details.

Four research areas were designated as follows:

Research Area 1: Ksar Ait Ben Haddou

Covering Ksar Ait Ben Haddou (see Figure 4), this research’s main emphasis is on this research area. Rich historical and cultural background defines this location, hence shaping the evolution of unique architectural forms.

Located in Ouarzazate Province, Morocco, Ksar Aït Ben Haddou is a fortified village famous for its well-preserved mud-brick construction, which displays traditional Moroccan building techniques [42]. Believed to originate from the 17th century, this historical landmark has multi-storied structures and narrow streets. These structures not only provided defense but also helped control inside temperatures. Unique to the Ksar, its architecture has earthen structures encircled by tall walls and corner towers. One of the best conserved Ksour in Morocco, this building style is a perfect example of southern Moroccan architecture.

Ksar Aït Ben Haddou has become internationally famous because of its unique architecture and picturesque setting and has been used as a location for filming movies and TV shows. Some of the films that have used this site include Lawrence of Arabia, Gladiator, and Game of Thrones [43,44]. In 1987, Ksar Aït Ben Haddou was inscribed as a World Heritage Site by UNESCO, thus increasing the profile of the site and leading to increased recognition of the need for conservation. The listing of sites like Ksar Aït Ben Haddou on the UNESCO World Heritage List is not only beneficial for the conservation of heritage but also for territorial marketing and place-making [45]. The designation also aims at creating awareness to the people on the cultural and natural history of these sites, and the need for their conservation and sustainable development [46]. Furthermore, the local communities’ participation in heritage conservation, as provided for in the UNESCO conventions, is relevant to the cooperative and sustainable management of the resources [47]. For this research, five buildings within Ksar Ait Ben Haddou were chosen. The buildings selected for this study fall within the region and are shown to exemplify the architectural and design features of Moroccan Kasbahs and Ksour. The particular buildings selected for this study region include Building 1, Kasbah Tebi; Building 2, Kasbah Ait Ougram; Building 3, Kasbah El Haja Guesthouse; Building 4, Dar Amghar—Tigmmi N Wawal/House of Orality; and Building 5, Tiwirga House.

As an illustration of the construction techniques and the use of the resources at hand in the local environment to produce a structure in harmony with the natural surroundings, Building 1, Kasbah Tebi, is introduced in Figure 5.

Building 2, Kasbah Ait Ougram, (Figure 6 below) is set apart by its fortified structure, which attests to the defensive needs and community lifestyle common in past times.

Building 3, Kasbah El Haja Guesthouse (Figure 7), can be seen as a link between traditional architecture and modern hospitality service, which can provide a good understanding of the traditional and “modern” aspects of this architecture.

Emphasizing the value of oral traditions and storytelling inside the local community’s legacy, Building 4, Dar Amghar—Tigmmi N Wawal/House of Orality, (Figure 8) stands as a cultural monument.

Finally, Building 5, Tiwirga House, (see Figure 9 for further details) represents the adaptive capacity and resilience of these architectural forms in response to evolving environmental and societal contexts.

Research Area 2: Ouarzazate City—Ksar Taourirt

The research site for Area 2 is located in the urban environment of Ouarzazate City and focuses on Kasbah Taourirt in Ksar Taourirt which stands as one of the principal sites for studying the urban morphology of Moroccan Kasbahs and Ksour. The area comprises three buildings which have been chosen to showcase its architectural characteristics. Building 6, Kasbah Taourirt—Small House 1 at East part “Stara”, is a good example of small houses that are integrated into the urban environment, which meet the needs of privacy and social interaction. (See Figure 10 for further details).

Building 7, Kasbah Taourirt—Medium House 2 at East part “Stara”, builds on existing design concepts by including architectural features that fit the changing needs of its inhabitants (see Figure 11 for further details).

Building 8, Kasbah Taourirt—Large House at East part “Stara”, reflects the historical grandeur and importance of Taourirt by combining features of defensive architecture with those of hospitality in its design. (See Figure 12 for further details).

Research Area 3: 9 km to Ouarzazate City

Located at a short distance from Ouarzazate City, Research Area 3 is solely represented by Kasbah Tifoultoute, (Figure 13) the one building selected for this area of study. Building 9, Kasbah Tifoultoute, stands as a regional architectural emblem, characterized by its robust construction and strategic positioning, intended to provide both defense and regional connectivity.

Research Area 4: Skoura

This study focuses on the Skoura area and two specific buildings that present different facets of the area’s history. Building 10, Kasbah Amridil, (see Figure 14 for further details) is an eloquent example of the local art and the wise management of the available resources in the oasian context.

Finally, Building 11, Kasbah Ait Ben Moro, enhances the architectural legacy of Skoura by showing the potential to balance the social and environmental context with housing needs. Every structure in Skoura offers insights into southern Moroccan architecture, providing design guidelines for both modern architectural adaptations and historical building techniques. (See Figure 15 for further details).

3.3. Methods

The current research utilizes a multi-scale approach and a multi-resource methodology that encompasses various data sources and literature reviews, including but not limited to satellite imagery, field visits, floor plans, and maps to investigate the integration of biophilic design principles within the vernacular architecture of Kasbahs and Ksour and to characterize their sustainability. To systematically evaluate the implementation of these principles, the Biophilic Interior Design Matrix (BID-M), a validated instrument developed by McGee et al. in 2019 [34], was employed. This matrix, recognized for its comprehensive and structured nature [48], offers a detailed framework for assessing biophilic design. The BID-M is composed of six elements, which are further delineated into 54 specific and measurable attributes [34].

Eleven sample buildings were examined from each of the four chosen research areas inside the Ouarzazate Province in order to investigate the complex link between the existing architectural biophilic design paradigms. The selection process sought to reflect the variety and similarities in the vernacular architectural heritage of the region. Detailed analysis of building facades and interior spaces and the specific study of elements such as doors, windows, and other relevant architectural features using an analytical approach, including the use of geospatial images, were used to apprehend the site context and spatial relationships. Each of these components was subjected to a systematic evaluation process designed to ascertain the degree to which these biophilic attributes are inherently manifested within these traditional architectural forms. By carefully blending knowledge from both historical architectural knowledge and the modern biophilic design theory, this study sought to bridge the gap between the appreciation and revitalization of their architectural qualities and the ongoing advancement of progressive design techniques. The BID-M framework provided a consistent and reproducible method for performing this assessment. A binary quantitative score was given for every one of the 54 biophilic attributes in the matrix. A score of 1 indicated the discernible presence of the attribute within the examined building, while a score of 0 denoted its absence. The aggregate data obtained from this systematic scoring process were subsequently synthesized and analyzed to establish a comparative understanding of the prevalence and characteristics of biophilic features across the four distinct research areas.

4. Results

4.1. Main Findings

After the assessment of the Biophilic Interior Design Matrix (BID-M), the consequent scores for the five buildings in Ksar Ait Ben Haddou—Buildings 1, 2, 3, 4, and 5—are uniformly 51 out of 54.

The Biophilic Interior Design Matrix (BID-M) scores for Buildings 6, 7, and 8 in Ouarzazate City—Ksar Taourirt are uniformly 50 out of 54 in Research Area 2. The BID-M score for Building 9 in Research Area 3 is 50 out of 54.

Finally, the BID-M scores for Buildings 10 and 11 in Research Area 4 in Skoura are, respectively, 51 and 50, out of 54. (See Figure 16 for further details and

Table A1. Evaluation scores of biophilic design for all 11 buildings within the four research areas using the BID-M.

Vernacular Building N°		1	2	3	4	5	6	7	8	9	10	11
N°	Attribute
Actual Natural Features
1	Air	1	1	1	1	1	1	1	1	1	1	1
2	Water	1	1	1	1	1	1	1	1	1	1	1
3	Plants	1	1	1	1	1	1	1	1	1	1	1
4	Animals	1	1	1	1	1	1	1	1	1	1	1
5	Natural materials	1	1	1	1	1	1	1	1	1	1	1
6	Views and vistas	1	1	1	1	1	1	1	1	1	1	1
7	Habitats	1	1	1	1	1	1	1	1	1	1	1
8	Fire	1	1	1	1	1	1	1	1	1	1	1
Sub score		8	8	8	8	8	8	8	8	8	8	8
Natural Shapes + Forms
9	Botanical motifs	1	1	1	1	1	1	1	1	1	1	1
10	Animal likenesses	0	0	0	0	0	0	0	0	0	1	0
11	Shells and spirals	0	0	0	0	0	0	0	0	0	1	0
12	Curves and arches	1	1	1	1	1	1	1	1	1	1	1
13	Fluid forms	0	0	0	0	0	0	0	0	0	1	0
14	Abstractions of nature	1	1	1	1	1	1	1	1	1	1	1
15	Shapes that are inside-out	1	1	1	1	1	0	0	0	0	1	0
Sub score		4	4	4	4	4	3	3	3	3	7	3
Natural Patterns + Processes
16	Sensory richness	1	1	1	1	1	1	1	1	1	1	1
17	Age, change, and patina	1	1	1	1	1	1	1	1	1	1	1
18	Area of emphasis	1	1	1	1	1	1	1	1	1	1	1
19	Patterned wholes	1	1	1	1	1	1	1	1	1	1	1
20	Bounded spaces	1	1	1	1	1	1	1	1	1	1	1
21	Linked series and chains	1	1	1	1	1	1	1	1	1	1	1
22	Integrations of parts with wholes	1	1	1	1	1	1	1	1	1	1	1
23	Complementary contrasts	1	1	1	1	1	1	1	1	1	1	1
24	Dynamic balance and tension	1	1	1	1	1	1	1	1	1	1	1
25	Natural ratios and scales	1	1	1	1	1	1	1	1	1	1	1
Sub score		10	10	10	10	10	10	10	10	10	10	10
Color and Light
26	Composition	1	1	1	1	1	1	1	1	1	1	1
27	Communication	1	1	1	1	1	1	1	1	1	1	1
28	Preference	1	1	1	1	1	1	1	1	1	1	1
29	Engagement	1	1	1	1	1	1	1	1	1	1	1
30	Pragmatics	1	1	1	1	1	1	1	1	1	1	1
31	Natural light	1	1	1	1	1	1	1	1	1	1	1
32	Filtered light	1	1	1	1	1	1	1	1	1	1	1
33	Reflected light	1	1	1	1	1	1	1	1	1	1	1
34	Light pools	1	1	1	1	1	1	1	1	1	1	1
35	Warm light	1	1	1	1	1	1	1	1	1	1	1
36	Light as shape and form	1	1	1	1	1	1	1	1	1	1	1
37	Spaciousness	1	1	1	1	1	1	1	1	1	1	1
38	Spatial variability	1	1	1	1	1	1	1	1	1	1	1
39	Space as shape and form	1	1	1	1	1	1	1	1	1	1	1
40	Spatial harmony	1	1	1	1	1	1	1	1	1	1	1
Sub score		15	15	15	15	15	15	15	15	15	15	15
Place-based relationships
41	Geographic connection to place	1	1	1	1	1	1	1	1	1	1	1
42	Historic connection to place	1	1	1	1	1	1	1	1	1	1	1
43	Ecological connection to place	1	1	1	1	1	1	1	1	1	1	1
44	Cultural connection to place	1	1	1	1	1	1	1	1	1	1	1
45	Integration of culture and ecology	1	1	1	1	1	1	1	1	1	1	1
46	Spirit of place	1	1	1	1	1	1	1	1	1	1	1
Sub score		6	6	6	6	6	6	6	6	6	6	6
Human–nature relationships
47	Prospect/refuge	1	1	1	1	1	1	1	1	1	1	1
48	Order and complexity	1	1	1	1	1	1	1	1	1	1	1
49	Curiosity and enticement	1	1	1	1	1	1	1	1	1	1	1
50	Mastery and control	1	1	1	1	1	1	1	1	1	1	1
51	Attraction/attachment	1	1	1	1	1	1	1	1	1	1	1
52	Exploration/discovery	1	1	1	1	1	1	1	1	1	1	1
53	Fear/awe	1	1	1	1	1	1	1	1	1	1	1
54	Reverence/spirituality	1	1	1	1	1	1	1	1	1	1	1
Sub score		8	8	8	8	8	8	8	8	8	8	8
Total		51	51	51	51	51	50	50	50	50	51	50

in Appendix A for the evaluation scores of the 54 attributes for each of the 11 buildings).

The data collected show the biophilia scores to be very high in these vernacular structures. This implies a great chance to harmonize the natural characteristics of architectural heritage with the principles of biophilic interior design. Consistently high scores across the data show that as judged by the Biophilic Interior Design Matrix, these historic architectural designs naturally include features that promote a relationship with nature. The averaged BID-M scores computed across all eleven analyzed vernacular buildings in the four Ouarzazate Province’s research areas are also rather high. This supports the general theory and emphasizes that on average, these structures show a strong biophilic quality. This high average score suggests that the incorporation of biophilic design is a common quality of the vernacular architecture in this region rather than being restricted to certain examples. See Figure 17 for the average scores by research area.

4.2. Research Limitations

This research aimed to assess biophilia in vernacular architecture in the Ouarzazate Province of Morocco, building upon the hypothesis that this region’s architectural heritage, based on local traditions, has a high potential for incorporation into contemporary biophilic design understanding. One limitation of this study is the number of buildings analyzed. The assessment of eleven vernacular buildings in four research areas of the Ouarzazate Province was conducted for this study, but further research could extend this sample to include additional architectural examples.

Furthermore, the study acknowledges the influence of tourism on certain vernacular buildings within the Ouarzazate region. Contemporary adaptations in some buildings catering to touristic demands may introduce elements that could potentially alter the original biophilic characteristics. However, this research also highlights a notable contrast. Rehabilitated buildings, such as the House of Orality/Tigmmi N Wawal in Ksar Ait Ben Haddou, strongly emphasize the inherent biophilic value embedded within these vernacular structures. This contrast suggests that while touristic pressures may lead to some deviations, the fundamental biophilic nature of vernacular architecture persists, particularly in buildings that prioritize preservation and rehabilitation.

Moving forward, further research could extend these assessments to other local contexts within the south of Morocco or North Africa and the wider Middle East region. Such comparative studies would be invaluable in developing nuanced biophilic design frameworks that authentically reflect the diverse local vernacular identities.

5. Discussion

The following discussion is articulated to address the main research question regarding whether the principles of biophilic design and sustainability can be characterized and assessed within vernacular architectural contexts through the assessment of 11 vernacular buildings in four research areas in the Ouarzazate Province in the south of Morocco using the Biophilic Interior Design Matrix (BID-M).

For the “actual natural features” representing the first element of the BID-M, it can be asserted that the architectural qualities of the assessed buildings largely met the criteria for fostering a connection with nature, such as environmental features like air, light, and natural materials. For example, the traditional materials used, including raw earth, clay and brick, stone, wet mud, palm-tree wood, and various kinds of reeds, contribute to the environmental value by integrating natural features into the building framework.

Regarding the “natural shapes + forms”, representing the second element within the BID-M framework, traditional architecture in Ksar Ait Ben Haddou, Ouarzazate city, and periphery as well as Skoura region often incorporates elements such as curves and arches that reflect natural shapes and forms. These architectural forms not only enhance aesthetics but also embody a certain cultural and historical significance of the region. In addition, decorative elements play a major role in supporting aesthetic and cultural values. These elements include intricate geometric patterns and motifs inspired by the natural environment. They are designed in a biophilic way to maintain privacy as in the biophilia framework’s emphasis on connection with nature.

Several researchers provide insights into the evolution of decorative styles in Amazigh defensive architecture, showing changes over time. In the earlier periods, especially from the 16th to the 17th century and up to the first half of the 19th century, the decoration of towers was notably rich and ornate. This period is often referred to as the “golden age” of Amazigh architecture [49], characterized by exuberant ornamentation, especially visible in structures like Kasbahs and tighermatin (meaning houses in Amazigh language). On the other hand, from the second half of the 19th century up to the present, there was a significant simplification in the facade decorations of towers. For instance, in Skoura, the towers no longer protrude from the facade and have minimal decoration.

The decorative features in this later period are described as simple and less detailed than in the earliest periods, with an emphasis on sobriety. Some other specific decorative elements include crowns, blind arches, and decorative horizontal bands. For instance, blind arches (see Figure 18), which were a recurring decorative element in the earlier periods, were often highly detailed with geometric patterns and served both aesthetic and functional roles. Over time, simple slits replaced more complex arch designs. Similarly, the shift from elaborate to simplified decorations is noted. Thus, over time, there was a shift from the intricate and detailed decorations of the earlier periods to more restrained and simplified designs in later years. This change reflects broader trends in architectural aesthetics and, possibly, shifts in the socio-cultural and economic contexts.

The third element (natural patterns + processes) is especially important in the context of these heritage buildings. This element aligns with the cultural heritage values, serving not only as decorative but also as functional features that segregate spaces for privacy and cultural practices. Courtyards, another architectural feature, provide natural ventilation and a communal space that enhances the livability of the environment, embodying the principles of biophilic design by promoting connection with natural processes (Figure 19).

Motifs based on the environment and local culture, including geometric, symbolic, Islamic, epigraphic, and botanical ones, express the aesthetic and religious values of the Ouarzazate Province in Morocco. A remarkable quality is traditional and religious sensitive ornamentation that honors both religious and traditional values, which is a feature of the vernacular architecture in the MENA region and closely fits the framework stressing cultural components in building designs. This culturally relevant artistic approach honors the established artistic traditions and reflects the cultural and religious values of the region. Throughout Ouarzazate, decorative arts such as Tadelakt and Zellij are commonly used. Whether simple or subtle, the decor enhances the visuals and promotes a warm and caring environment.

The fourth component “color and light” depicts vernacular buildings in Ouarzazate using native hues to produce visually rich and ecologically sensitive settings. The natural surroundings are harmonized by the color pallet of ochre and sienna earth pigments and plant-based dyes. The bright natural hues reflect sunlight and lower heat entrance, hence improving sights and preserving thermal comfort.

Embedded in Ksourian vernacular architecture, the fifth element is “place-based relationships”. Building design and orientation have an intricate relationship with the local physical and cultural background. Architectural shapes and spatial layouts reflect ancient social customs, hence enhancing the cultural identity and feeling of belonging. Reflecting the cooperative living, the Kasbah design promotes social contact by means of linked courtyards and communal areas. Religious values, such as privacy, respect for family and women spaces, and ornamentation reflecting Islamic artistic principles, are vital in interior design and display local adaptations in southern Morocco. Vernacular homes often feature courtyards as private spaces, with window designs that carefully balance light and privacy and the concept of “seeing and looking at the outside world without being seen” as it is presented in Figure 20.

To end, the sixth component of biophilic design in these buildings is “human–nature relationships”. These structures show a knowledge of natural processes and are well fit for the severe desert environment. The thick earthen walls serve as temperature regulators between extreme heat and cold while the courtyards enable natural ventilation and cooling.

Future studies extending these evaluations over the larger Middle East might help to create biophilic design frameworks, therefore supporting the integration of biophilic components as a common feature of the vernacular architecture in the region. The results of this study highlight the need to maintain the traditional architecture of Moroccan Kasbahs and Ksour so as to produce and design new projects in the region inspired by their intrinsic biophilic attributes.

Sustainability in Moroccan Kasbahs and Ksour:

The construction techniques and architectural features of Moroccan Kasbahs and Ksour show sustainable principles expressed in their architectural typology and urban morphology. In fact, the designs of Kasbahs and Ksour include balance, adaptation, diversity, proportionality, and social norms to generate sustainable living environments. See Figure 21 for further details.

Two of the fundamental concepts of sustainable design demonstrated in Kasbahs and Ksour are adaptability and balance. Made from locally obtained materials including clay, stone, and palm wood, these materials are not only readily available but also perfectly suited for the environment of the region. Natural ventilation also greatly influences the architecture of these structures. Thick earthen walls and strategically placed windows and openings let air flow, hence maintaining cooler inside temperatures during hot days and warmer conditions during cooler evenings.

6. Conclusions

The sustainability of vernacular architecture can be analyzed through various dimensions, including environmental, socio-cultural, and economic aspects. Giuffrida and Caponetto note that vernacular architecture is a product of trial and error, shaped by local resources, climate, and socio-economic contexts, which results in structures that are not only functional but also sustainable [50]. This is further supported by Karahan et al., who argue that learning from vernacular architecture can lead to sustainable architectural models that maximize comfort while minimizing energy consumption [51]. As Fernandes et al. point out, the inclusion of local materials and methods is notable since vernacular materials have less environmental impact than industrially manufactured substitutes [52]. Furthermore, the principles of sustainability in vernacular architecture go beyond simple environmental concerns. Rosaleny-Gamón addresses how vernacular architecture reflects teachings in sustainability relevant to contemporary urban issues, therefore addressing environmental, economic, social, and cultural sustainability [28]. The empirical development of vernacular architecture as a paradigm for sustainable practices can support research techniques that may enhance its relevance in contemporary contexts, thus mirroring a holistic approach [53,54].

Vernacular architecture emerges from local contexts to express sustainable design principles. It contains fundamental principles that guide the development of sustainable and resilient built environments during the current global urbanization and climate change crisis.