Tracing the Morphogenesis and Formal Diffusion of Vernacular Mosques: A Typo-Morphological Study of Djebel Amour, Algeria

Abstract

The Djebel Amour region, located in the Western Saharan Atlas of Algeria, hosts a vernacular mosque heritage that remains largely unexplored. This study presents the first comprehensive typo-morphological analysis of fourteen mosques dating from the 11th to the 20th century. Their original architectural state was reconstructed through the triangulation of field surveys, archival documentation, iconographic sources, and oral testimonies. A reference model based on four recurrent components—the prayer hall with its mihrab, courtyard, portico, and minaret—enabled the identification of typological constants, contextual variations, and vernacular constructive logics. The results reveal the persistence of sober and functional forms, marked by the frequent absence of a courtyard and the presence of skiffa-inspired porticos and staircase minarets. A complementary quantitative component strengthens cross-regional comparisons and situates the Djebel Amour corpus within wider North African, West African, Middle Eastern, and Southeast Asian vernacular mosque traditions. Beyond architectural reconstruction, this study develops an operational framework for conservation and transformation management, supported by a structured database that systematises typological, material, and construction data. While the analysis relies primarily on photogrammetric documentation, the proposed framework is compatible with international digital standards and can be expanded through methods such as 3D laser scanning, drone-based surveys, or geospatial modelling. By integrating qualitative, quantitative, and digital perspectives, this research offers practical tools for heritage authorities, local administrations, mosque committees, architects, designers, and conservation practitioners, positioning the Djebel Amour mosques as a reference model for sustainable heritage management and contextual adaptation in arid and tribal environments.

1. Introduction

From the earliest days of Islam, the mosque has established itself as the central religious building dedicated to collective prayer [1,2]. Its original form, inherited from domestic architecture, combined a courtyard and a prayer hall, and despite certain external influences, it has always retained its own identity. At the same time, this form has shown great plasticity, which, together with the simplicity of Islamic liturgy, has enabled it to adapt to highly diverse built and cultural contexts while fulfilling its essential function as a place of prayer.

Beyond this religious function, the mosque has been a real community hub since the beginning. It has historically served multiple social purposes—meetings, teaching, justice, and charity work—ranging from assisting the poor to welcoming travellers [3,4,5]. However, over time, some of these functions have become specialised in annexes, and the mosque has remained at the heart of the Muslim religious architecture, confirming its universal spiritual and social role [4].

Over time, the mosque has gradually given rise to a wide variety of architectural forms throughout the Muslim world. On the one hand, monumental mosques, symbols of dynastic power and cultural influence, have established themselves as major landmarks in Islamic history. On the other hand, a more discreet, vernacular style developed within local communities, shaped by traditional skills and the social and environmental conditions specific to each region. Recent studies on vernacular architecture in arid environments have further shown how traditional building cultures embed environmental intelligence, the material economy, and climatic adaptation within their spatial and constructive logic [6], highlighting the sustainability potential of local craftsmanship.

The mosques of Djebel Amour fall into this second category. Located in the heart of the Algerian Saharan Atlas, this transitional region is characterised by the permanence of tribal structures and the presence of ksour, fortified villages adapted to ecological constraints and constitutive of religious and community life. The vernacular mosques found there express a Saharan religious architecture shaped by local realities and reveal an original style that remains largely undocumented.

Although the typology and morphology of Islamic mosques have been analysed in reference works [1,3,4,7,8,9], vernacular Saharan buildings remain largely absent from historiography. This gap is particularly striking in the Djebel Amour region, where mosques combine canonical features of Islamic architecture—prayer hall with mihrab, minaret—with local adaptations, such as the frequent absence of a courtyard, the use of porticos inspired by the domestic skiffa, and the presence of staircase minarets. The challenge is therefore to understand how these buildings, modest in appearance, nevertheless constitute a representative corpus of the social, cultural and technical dynamics of the Algerian Sahara.

The present study has three main objectives. First, it seeks to trace and analyse the architectural morphogenesis and spatial evolution of fourteen vernacular mosques in Djebel Amour. Second, it aims to examine how these buildings articulate canonical continuities with local adaptations within their environmental and cultural context. Third, it demonstrates how a typomorphological framework can inform conservation strategies and the sustainable management of restoration interventions, preserving vernacular identity within a changing socio-religious landscape.

This research represents the first systematic architectural investigation of the vernacular mosques located within the tribal ksour of Djebel Amour. Its originality lies not only in documenting a corpus that has never been analysed comprehensively but also in integrating spatial, social and material interpretations with metric data obtained through photogrammetric architectural surveys. By identifying distinctive regional expressions and adaptive architectural responses, the study positions the Djebel Amour corpus within a wider comparative framework that includes North African, West African, Middle Eastern and Southeast Asian vernacular mosque traditions. In particular, contrasts with regions such as the Souf, the M’Zab Valley, the oases of Al-Khabra, the earthen mosques of West Africa, the hypostyle vernacular mosques of the Arabian Peninsula, and the timber or multi-tiered mosques of Indonesia and Malaysia reveal the specific identity, spatial coherence and constructive logic that characterise the Djebel Amour tradition.

To address these objectives, the study adopts a typomorphological methodology combining archival sources, architectural surveys, iconographic documents and oral testimonies. The architectural surveys include photogrammetric recordings that provide accurate dimensional data, enabling both precise morphological analysis and the construction of quantitative indicators used to structure regional comparisons. This approach, particularly suited to vernacular architecture, identifies structural constants while accounting for local variations, thereby revealing the adaptive processes that shaped these mosques.

Beyond spatial and morphological analysis, the study examines the constructive and material context in which these buildings were produced. By analysing traditional techniques and locally sourced materials, it highlights how local craftsmanship reinforces architectural coherence and sustains vernacular authenticity.

Building on these insights, the research establishes comparative references drawn from both regional literature and newly generated quantitative data. These benchmarks support the evaluation of contemporary interventions, such as enlargements of prayer halls or restoration works, demonstrating that a combined qualitative and quantitative understanding of original configurations is essential for preserving architectural identity and cultural meaning.

Ultimately, this study reveals the plasticity and resilience of Saharan religious architecture, situating the Djebel Amour corpus within a broader international trajectory of vernacular mosque traditions while emphasising the socio-cultural specificities that shape its originality.

2. Evolution of Mosque Typologies: From Canonical Forms to Vernacular Traditions

Since the 7th century, the expansion of Islam has been accompanied by a remarkable diversification of mosque architectural types. The literature traditionally distinguishes three canonical models: the hypostyle or Arab type, based on the Medina prototype; the Iranian type, developed under the Seljuks and spread as far as Central Asia; and the Turkish type, characteristic of Ottoman architecture and inspired by the Byzantine model [10,11]. Tajuddin and Rasdi [12], add three regional variants: the Indian type, the Chinese type and the Southeast Asian type, which reflect the integration of local materials, expertise and motifs (Figure 1).

This typology, far from being fixed, has been widely discussed by authors who have proposed other ways of thinking about the mosque beyond its canonical forms. Hillenbrand [1] emphasises that the mosque is not defined by its architectural monumentality, but above all by a sacred space oriented towards the qibla, which explains the morphological plasticity of the hypostyle type. For his part, Kuban [4,7] analyses how functional elements—mihrab, minbar, minaret, courtyard, and maqsura—have gradually become institutionalised, generating a standard typology that can be adapted to regional contexts.

In this vein, the Maghreb model can be considered a skilful and coherent adaptation of the hypostyle plan. It is characterised by a rectangular enclosure (haram), a prayer hall organised into bays, a sahn surrounded by porticoes, a mihrab sometimes surmounted by a dome and, above all, a square minaret, the architectural emblem of the Maghreb [13]. Sober but symbolically powerful, this model serves as a reference for analysing the typological and morphological variations in the vernacular mosques of Djebel Amour.

These are not simply a matter of formal reduction. They reflect the logic of cultural and material adaptation, where local construction constraints and community traditions redefine architectural canons (Figure 2).

While canonical models reflect a scholarly tradition developed in the great centers of power, Islamic religious architecture cannot be limited to these monumental forms.

It also finds expression in local contexts, where communities reinterpret established canons according to their resources, traditions and environment. It is in this dynamic is the concept of vernacular religious architecture, understood not as an impoverished version of the canon, but as a contextualised adaptation where religious practices are expressed through local spatial and material solutions.

The literature defines vernacular architecture as local, anonymous and contextualised production. For Rapoport [14], it constitutes a mode of construction shaped by culture, social practices and available resources, reflecting a direct relationship between humans and their environment. Oliver [15] emphasises its collective and spontaneous nature that developed without architects, but according to empirical rules, it inherited this nature and transmitted it at the community level. Ebru Aydeniz and Fellahi [16] point out that the term “vernacular”, derived from the Latin vernaculus, refers to that which is “specific to a region”.

Several recent studies have focused on analysing vernacular mosques in different geographical contexts. This work provides an essential frame of reference for situating our own contribution, highlighting the diversity of approaches and the richness of forms that this contextualised religious architecture can take.

M. Osman [17], in a study focused on Mali, challenges the centrality of the dome and advocates a more sober design, adapted to the climate and community needs, favoring functionality and local materials.

Ghanbari [18] developed the notion of “architectural creolisation” for West African mosques. His analysis highlights the combination of Dogon heritage (domestic forms, temples, and cosmology) and the Medina prototype. Through several case studies (Fouta-Toro, Mopti, Djenné, and Bobo-Dioulasso), he proposes a grid of correspondences that highlight the fusion between Islamic practices and local traditions.

Alghafis and Sibley [19] make an innovative contribution based on the case of Al-Khabra in Saudi Arabia. Through field research and interviews, they identify five spatial components (al-Khalwa, al-Misbah, al-Sarha, al-Eshah and al-Sath) that reflect bioclimatic and social adaptation. The Great Mosque is described as a multifunctional space, while the authors warn against certain modern restorations that compromise the original vernacular qualities.

From another perspective, Khalid [20] analysed the Great Mosque of Djenné (Mali), which, according to Nader Ardalan [21], consists of a grid of “generic forms”. She shows that the mihrab is the central element, while the dome and porticos are absent for ecological reasons. The study highlights the community dimension of the annual ritual maintenance, revealing an architecture where material sustainability and social cohesion come together.

More recently, Zerari et al. [22] examined vernacular mosques in Souf, Algeria. Their research highlights the existence of a distinctive local architectural language, the result of a process of acculturation where Saharan, Arab, Berber and sometimes colonial influences intersect.

These contributions demonstrate the breadth and richness of research conducted on vernacular mosques in various contexts. However, they remain focused on a few regions or specific architectural elements, leaving other areas of the Sahara marginalised. In our case, the vernacular mosques studied are traditional buildings, rooted in a fortified village structure called ksar (plural ksour). The term, of Arabic origin and related to the Greek word kastron and the Latin word castrum, originally referred to a fortified place. In the Maghreb and the Sahara, its meaning has broadened to refer to forms of defensive collective housing, combining a built-up area with agricultural land. Ksour thus appear as fortified rural settlements, organised around a community space and integrated into an oasis system [23,24,25]. Unlike vernacular mosques studied in other contexts—often analysed from the perspective of architectural forms or climatic and social adaptations—those in Djebel Amour are distinguished by their integration into these fortified villages, where they constitute both a religious center and a marker of identity at the heart of the ksar.

3. Study Area: Geographical and Socio-Cultural Context of Djebel Amour

The Djebel Amour is part of the western Algerian Saharan Atlas, between the Ksour Mountains to the west and the Ouled Naïl Mountains to the east [26,27]. Formerly known as Djebel Rached, it was first occupied by the Beni Rached Berber tribes, then gradually Arabised from the 13th century onwards with the arrival of the Amour Arab tribe, which gave its name to the massif [26,27,28].

With their permanent settlement, the Amour people developed a semi-nomadic pastoral lifestyle based on transhumance between mountainous areas and plains. This system, deeply influenced by ecological complementarities, was disrupted by colonisation and modernisation, evolving towards almost universal sedentarisation [27,29]. This sedentarisation was notably reflected in the ksour, fortified villages built near permanent water sources, which illustrate the local ingenuity in adapting to the arid environment and remain a marker of identity to this day [28].

Although traditional geographical representations have defined it as a pivotal area of the northern Sahara, Djebel Amour is the main study area for this research (Figure 3). Although it falls administratively under the wilaya of Laghouat, it is its geographical, historical and cultural territory that is the subject of this analysis.

4. Methods and Materials

The methodological framework adopted in this study follows a hybrid and sequential structure integrating three complementary components. First, a qualitative approach (Section 4.1), based on the triangulation of field surveys, archival documentation, iconographic material and oral testimonies, provided a robust empirical foundation and ensured the historical and contextual relevance of the data collected. Second, a typomorphological approach (Section 4.2) served as the principal analytical framework. Specifically adapted to the spatial and social logic of tribal settlements, it connects architectural form with lineage structures and collective religious practices. Its application to the vernacular mosques of the Djebel Amour constitutes an original contribution, enabling the identification of both recurrent morphological patterns and region-specific variations within an understudied corpus.

To enhance the analytical transparency of this interpretative framework and to organise comparisons with existing scholarly benchmarks, a complementary quantitative component (Section 4.3) was integrated. By translating selected architectural variables into measurable indicators, this component reinforces the typomorphological reading while preserving the qualitative depth of the analysis. Together, these three methodological layers provide a coherent, rigorous and multi-dimensional foundation for examining the architectural identity and spatial evolution of the vernacular mosques of the Djebel Amour region.

4.1. Qualitative Approach

4.1.1. Selection of Sample and Documentation Sources

• Survey Sheet

Each mosque was systematically surveyed, recording its date, location, morphology, spatial and structural configuration, materials, state of conservation, interventions, and architectural or historical notes. During these field campaigns, a Canon EOS 750D digital camera was used to carry out photogrammetric recordings, providing accurate three-dimensional documentation of the existing structures. This architectural survey technique—particularly suitable for vernacular environments where geometries are irregular and difficult to measure with conventional tools—was applied mainly to interior spaces, especially structural elements such as pillars and columns, and processed using Agisoft Metashape (free standard version). The purpose of this procedure was not to reconstruct missing parts but to complement the descriptive and dimensional data obtained through direct observation (Figure 4).

The photogrammetric documentation was processed through six sequential stages: (1) image alignment, (2) dense cloud generation, (3) mesh reconstruction, (4) texture mapping, (5) model export, and (6) final rendering. Each stage produced verifiable and scalable datasets—orthophotos, point clouds, and textured 3D models—enabling precise quantitative analysis of spatial and morphological features. The full workflow and its measurable outputs are shown in (Figure 5), illustrating the entire sequence from image acquisition to final model generation.

This approach is fully aligned with the growing field of digital heritage documentation, in which photogrammetry, 3D modelling and geospatial integration have become essential tools for ensuring accuracy, durability and traceability of heritage records. Recent studies have demonstrated that such technologies significantly enhance the reproducibility of surveys and the long-term sustainability of conservation actions [30,31]. In this respect, the photogrammetric records of the Djebel Amour mosques contribute not only to typomorphological analysis but also to the creation of a durable digital repository for vernacular architecture in arid regions.

The information collected during field observations was subsequently systematised to clearly identify the morphological constants and specific features that define the vernacular mosques of Djebel Amour.

• Written and archival sources

The archives of the Directorate of Culture (DC), the Directorate of Religious Affairs and Waqf of Laghouat (DRAW), and the National Office of the Saharan Atlas Cultural Park (ONPCAS) in the region studied provided reports, articles, and iconographic documents, supplemented by the expertise of local specialists. In addition, there are travelogues and studies from the colonial period [32,33,34,35,36,37], as well as recent works by contemporary authors [38,39,40,41]. These materials place the mosques in their historical context and allow us to follow their evolution.

• Iconographic documents

A visual corpus was compiled from old maps and photographs, notably via the Delcampe platform. Despite difficulties in accessing old photographs, E. Cat’s [42] work provided rare and valuable images.

These documents made it possible to confirm or supplement the data from surveys and written sources.

• Interviews and field observations

Between 2022 and 2025, semi-structured interviews were conducted with residents, users and experts on local heritage. They focused on the chronology, transformations and identity of the building tribes, to reveal external influences and exogenous contributions. These testimonies were cross-referenced with direct observations made during regular site visits. The use of photogrammetry strengthened this fieldwork by ensuring metric accuracy and by producing visual records to be compared with archival and oral data. Cases of mosques that had undergone complete renovations were excluded to ensure the relevance of the morphological analysis. All these sources were used not only to compile and document the corpus, but also to clarify and consolidate the interpretation of the results. They will thus be used in the discussion to compare the data collected in the field with historical, iconographic and oral contributions.

To ensure the reliability of these heterogeneous materials, all sources were critically assessed through cross-verification and triangulation. Conflicting oral testimonies were compared with archival and iconographic evidence, while incomplete or biased records were contextualised through comparative analysis with other documented cases in the region. This methodological reflexivity helped to mitigate potential biases and to strengthen the consistency and credibility of the empirical data used in this research.

The empirical data collected through field surveys, archival research, and photogrammetric documentation provided a comprehensive basis for identifying representative cases. On this foundation, the study corpus was defined according to clear selection criteria, as presented in the following section.

4.1.2. Constitution of the Study Corpus

The study corpus was defined according to specific criteria designed to ensure its representativeness and scientific relevance, rather than to establish an exhaustive inventory of all mosques in the region. The selection was based on the following parameters:

• Dating

The mosques selected cover a broad chronological period ranging from the 11th to the 20th century, divided into two distinct periods: the pre-colonial period (11th–mid-19th century) and the colonial period (mid-19th–20th century).

• Location

The selection includes the entire territory of Djebel Amour, divided between seven ksour: Aïn Madhi, Sidi Bouzid, Laghouat, Tadjmout, Taouila, Tadjrouna and Houaita.

• Functional typology

Only Djamaa-type mosques were selected, as they were the main places of collective prayer and social life within each ksar.

• Tribal affiliation and social roots

Each mosque has been identified according to its neighbourhood or founding tribal group, to understand the links between religious morphology and local social structure.

• State of conservation and morphological reconstruction

Only mosques whose original structures remain visible were retained, ensuring a reliable interpretation of their initial configuration. This assessment was supported by field surveys, administrative archives (Direction of Culture, Direction of Religious Affairs and Waqf, PPSMVSS), academic works [43,44,45,46,47,48,49], and specialised publications [28]. The objective was not to reconstruct lost buildings theoretically, but to identify comparable morphological constants across the sample.

One case is worth highlighting: several mosques have undergone extensions, particularly to the prayer hall, to accommodate population growth. However, the distinctive feature of the vernacular mosques of Djebel Amour is the systematic preservation of the original part, which still forms the core around which the extensions are organised. In this context, the Khalifa (or Ahlaf) mosque illustrates a unique situation. Originally built during the precolonial period, it has been restored to its colonial-era state due to the lack of documents, archives or precise records relating to its original condition. Nevertheless, the analysis and discussion also consider its original organisation, as reported by available oral sources, which allows both historical phases of its evolution to be integrated.

Based on these criteria, fourteen representative specimens (S1–S14) were selected: five in Laghouat, two in Aïn Madhi, two in Tadjmout, two in Taouila, one in Sidi Bouzid, one in Tadjrouna, and one in Houaita (

Table 1. Vernacular mosques of Djebel Amour: spatial plans and chronological classification.

Spatial Plans of Vernacular Mosques of Djebel Amour
Precolonial specimens (11th–19th centuries)
Colonial specimens (19th–20th centuries)
Legend: (1) Prayer Hall, (2) Courtyard, (3) Minaret, (4) Mausoleum, (5) Annexes
Identification specimens
(S1) Al-Atik Mosque in Ain Madhi (11th century); (S2) Sidi Bouzid Mosque (12th century); (S3) Al-Atik in Laghouat Mosque (12th century); (S4) Al-Atik Tadjmout Mosque (16th–17th centuries); (S5) Ouled Saci Mosque after reconstruction (19th century); (S6) Taouti Mosque (1864); (S7) Safah Mosque (1874); (S8) Abdelkader Djilali Mosque (1872); (S9) Khalifa or Ahlaf Mosque after conversion (20th century); (S10) Ouled Turki Mosque (XIX-XX); (S11) El-Atik Mosque in Haouita after reconstruction (1936); (S12) El-Atik Mosque in Tadjrouna after reconstruction (19th century); (S13) Mohamed Sidi Mohamed El-Habib Tidjani in Ain Madhi (19th century); (S14) El-Houda Mosque in Tadjmout (19th century).

).

This corpus forms the empirical foundation of the study and is analysed using the typomorphological framework presented in the following section.

4.2. Typo-Morphological Approach as an Analytical Framework

The typo-morphological approach, initiated in the 1960s by Saverio Muratori and later developed by Aldo Rossi, Carlo Aymonino and Gianfranco Caniggia, has become a fundamental framework for analysing architectural and urban form through its constitutive elements. Rooted in the combined study of typology and morphology, it investigates recurrent spatial structures and their historical evolution, while considering socio-cultural and environmental contexts. The approach was later enriched by the French school, notably through the work of Philippe Panerai [50], who emphasised the relationship between built form, social practices and territory. Together, these contributions established a methodological tradition capable of revealing the genesis, permanence and transformation of architectural forms [11,22,51,52,53,54].

Although originally devised for urban and residential fabrics, this approach has progressively been extended to religious architecture, particularly mosques. Three main research themes have emerged: (1) the historical and morphological evolution of mosque forms in relation to political and cultural dynamics; (2) the adaptation of mosque architecture to contemporary contexts, balancing continuity and innovation; and (3) comparative classifications distinguishing canonical structures from regional or vernacular expressions. This analytical flexibility has been demonstrated across diverse geographies—including Malaysia, Tunisia, Turkey, Iraq, Algeria, Iran, Indonesia, northern Greece, Saudi Arabia and Afghanistan—confirming its methodological robustness and universal relevance [11,51,55,56,57,58,59,60,61,62,63,64]. In most cases, the method relies on typology as a reference framework, often through the construction of an ideal model [55,60], used to assess local adaptations and morphological variations.

Beyond these developments, certain lines of research have deepened the method by mobilising L’Analyse des Formes (LAF), first devised at the Lyon laboratory under the direction of Bernard Duprat. Initially conceived for the study of domestic architecture and urban façades [65,66,67], LAF was later applied to Islamic religious heritage, particularly in the Maghreb. Several contributions have focused on minarets: Chakroun [68] identified the morphological characteristics of the Ottoman period, Zerari et al. [69] examined the diversity of ancient minarets in Ziban region, Benabadji and Bencherif [70] characterised the identity of Ziyanid minarets in Tlemcen, while Beldjilali et al. [71] offered a monographic reading of medieval minarets in northern Algeria. Other works extended the approach to whole mosques: Msadek [72] characterised Tunisian mosques from the 7th to the 19th century, Cherif & Bouhoula [73] established a morphological classification of ancient Tunisian mosques in order to highlight their typological diversity and their links with the historical and cultural context, and Zerari et al. [22] studied the vernacular mosques of Souf, revealing a vernacular style marked by unique silhouettes, such as the staircase minaret and the raised dome.

For Algeria, Bourouiba’s studies [74,75] remain a major reference for morphology and typology of monumental mosques associated of the Almohad, Ziyanid, Marinid, and Ottoman dynasties. Parallel to this monumental corpus, significant attention has been devoted to the Ibadite mosques of the M’Zab Valley, whose spatial coherence and constructive rationality have been documented in depth [76,77,78].

Building on this tradition, Sriti et al. [79] introduced an early structured application of LAF to Saharan vernacular mosques, proposing one of the first systematic frameworks for interpreting spatial organisation and constructive logics in desert religious architecture. Zerari’s later doctoral research [80], supervised by Sriti, expanded and consolidated this analytical framework at a broader scale, deepening the characterisation of mosques in the eastern Sahara and demonstrating the methodological continuity between both studies.

Despite these advances, the literature remains fragmented. Most studies concentrate either on monumental dynastic mosques or on well-documented regions such as the M’Zab and the Bas Sahara, while often isolating specific architectural elements—notably the minaret. In contrast, the vernacular mosques of the Djebel Amour—situated in a transitional Saharan-Atlas context—remain largely absent from scientific discourse, despite their strong typological, cultural and patrimonial relevance. In this region, research remains limited to a few isolated works: Chettih’s doctoral thesis [49] on the restoration of the historic mosques of Laghouat; Hamlaoui’s book [28] on ksour, which dedicates only a few pages to their religious buildings; and three master’s dissertations [46,47,48], each examining a single mosque. To date, no study has undertaken a systematic typo-morphological investigation of this corpus or examined it across both the pre-colonial and colonial phases to trace its spatial evolution and architectural adaptation.

At the same time, the literature reviewed not only provides a theoretical foundation but also offers critical comparative benchmarks for situating the present findings within a broader disciplinary discourse. This dual scientific function reinforces the relevance of extending typo-morphological inquiry to this neglected corpus.

The analytical framework developed here builds upon a reference model derived from established theoretical contributions, subsequently calibrated to the specific context of the Djebel Amour. It relies on four essential architectural components—the prayer hall with its mihrab, the courtyard, the portico, and the minaret—to which various annexes may be added. The analysis unfolds across three complementary levels. First, the level of morphological genesis and typological structures examines the spatial organisation and internal components of the mosques, including the prayer hall, mihrab, courtyard, portico, and annexes, to identify both recurrent configurations and context-specific variants. Second, the level of vertical identity focuses on the minaret as a defining architectural and symbolic element situated at the intersection of Eastern traditions and colonial influences, analysing its evolution and its role within the landscape of the Djebel Amour. Third, a constructive perspective is introduced, addressing predominant building systems and materials; although not the central focus, this dimension situates the typo-morphological interpretation within the environmental and technical rationalities of vernacular architecture. By linking form, material, and context, this methodological framework provides a holistic understanding of the Djebel Amour mosques and establishes a rigorous analytical basis for assessing their long-term preservation and adaptive transformations.

The typomorphological framework developed in this study constitutes an original analytical tool designed to interpret the relationship between architectural evolution and socio-historical context. Although inspired by established morphological theories, its application to the tribal ksour of Djebel Amour represents a new conceptual model that can be extended to other Maghrebi contexts.

To ensure that the typomorphological interpretation developed above rests on a transparent and analytically verifiable foundation, the study integrates a complementary quantitative component. While the core of the analysis remains rooted in the morphological and socio-historical reading of the corpus, certain architectural variables—identified as key comparative markers in the literature—benefit from being expressed through measurable indicators. This additional layer does not modify the typomorphological framework but reinforces its conclusions by structuring cross-regional comparisons and enhancing the reproducibility of the findings. The following section outlines this quantitative component and clarifies its role within the overall methodological architecture of the study.

The theoretical and empirical foundations of the study are summarized in the following section (

Table 2. Theoretical and empirical foundations of the typo-morphological analysis in the present study.

Category	Origin/Author (s)	Nature/Field of Study	Main Contribution
Empirical sources	Field surveys (2023–2025)	Survey sheets (date, location, morphology, materials, conservation status, interventions)	Identification of historical and morphological characteristics
	Photogrammetric documentation (Canon EOS 750D, Agisoft Metashape)	Orthophots, point clouds, textured 3D models	Metric accuracy, support for morphological reconstruction
	Archives: Directorate of Culture, Directorate of Religious Affairs and Waqf and ONPCAS Travel accounts: M. Marey, 1846; E. Fromentin, 1857; E. Dermenghem, 1960; O. Petit, 1976; G. Hirtz, 1989 [32,33,34,35,36] Recent authors: M. Labter, 2020; A. Saoudi, 2020; K. Sonne; 2020 and L. Labter, 2021 [38,39,40,41]	Reports, articles and documentary sources	Historical context, transformations, evolution of uses
	Iconographic documents: Delcampe; E. Cat 1892 [42]	Old maps, photographs,	Verification and enrichment of surveys and archival sources
	Interviews and field observations: inhabitants, experts and visits 2022–2025	Oral testimonies and direct observations	Chronology, tribal identity, external influences
Typological and morphological references	Previous university studies: Habboul, 2011, Takhi, 2018; Mahcer et al. 2018; O. Talha, 2018; T. Haizoum, 2018; Rabhi, 2018; Chettih, 2019 [43,44,45,46,47,48,49] Archives: PPSMVSS Monographs: Hamlaoui, 2006 [28]	Theses and archival documents	Scientific support for morphological restitution and corpus selection
	Muratori, Rossi, Aymonino, Caniggia (1960s–1980s); Panerai (1980s–2000s) [50]	Italian and French typo-morphology schools	Foundations and adaptation of the typo-morphological approach
	Othman et al., 2008 [55]; M. Redjem 2014 [56]; M. Loukma & M. Stefanidou, 2017 [58]; Budi & Wibowo, 2018; Elkhateeb et al., 2018; Mustapha & Ismael, 2019; Redjem & Mazouz, 2022; Asim & Hajime., 2022; Fakriah, N. 2022 [11,59,60,61,62,63]; Abubakr Ali & Mustapha, 2023 [53]	International studies on historical and traditional mosques	Comparative typological analysis
	Duprat and Paulin, 1989; Sriti. L, 1996; 2013 [65,66,67]; I. Msadek, 2012 [72]; H. Gaci 2012 [51]; I. Cherif & N. Allani-Bouhoula, 2015 [57]; Chakroun, 2016 [68]; I. Cherif & N. Allani-Bouhoula, 2017 [73]; Zerari et al., 2020; Benabadji & Bencherif 2020; Beldjilali et al., 2024 [69,70,71]; Zerari et al., 2024 [22]	Mosques of the Maghreb	Morphological analysis (classification and minaret studies)
	J. Schacht, 1954 [78]; Bourouiba, 1983–1986 [74,75]; V. Prévost, 2009; N. Benkari, 2018 [76,77,81]; Sriti et al., 2018 [79]; Zerari, 2021 [80]	Monumental and Ibadi mosques	Comparative historical and Saharan studies
	A. Hamlaoui, 2006 [28]; O. Talha, 2018; T. Haizoum, 2018; Rahbhi, 2018; Chettih, 2019 [46,47,48,49]	Vernacular mosques of Djebel Amour	Initial local and partial studies

), and the overall methodological workflow is illustrated through a diagram (Figure 6).

4.3. Quantitative Comparative Approach

In order to strengthen the methodological structure of the study and to align with recent expectations for more systematic comparative analysis, a quantitative component was integrated alongside the qualitative and typomorphological approaches. Although the core of the research relies on field surveys, archival documentation and morphological interpretation, the construction of a coherent corpus made it possible to extract measurable indicators and organise them into frequency tables and comparative distributions.

This quantitative layer does not replace the typomorphological reading; rather, it supports it by providing reproducible evidence and by situating the Djebel Amour corpus within broader regional and disciplinary contexts. Architectural components such as minaret types, courtyard occurrence and portico configurations were translated into numerical variables, enabling structured comparisons with existing studies.

The detailed numerical results of this quantitative treatment are presented in Section 5, where they substantiate the typomorphological interpretations and contribute to the broader analytical conclusions of the study.

5. Results and Discussion: Typo-Morphological Adaptations of Vernacular Mosques in Djebel Amour

This section presents the analytical and interpretative results of the study, focusing on the typo-morphological adaptations of vernacular mosques in Djebel Amour. The objective is to assess how these mosques reproduce, transform, or depart from canonical models in response to the region’s social, historical, and environmental specificities. The analysis operates on three complementary levels: a two-dimensional level, examining spatial configuration and the main morphological components (prayer hall, courtyard, portico, and annexes) (Section 5.1); a three-dimensional level, exploring the evolution of the minaret as a vertical and symbolic element at the intersection of Eastern traditions and colonial influences (Section 5.2); and a constructive level, addressing the building systems and materials that reflect the local craftsmanship and environmental adaptation of these mosques (Section 5.3).

Together, these analyses provide a comprehensive understanding of the architectural identity of the Djebel Amour mosques, revealing their capacity to integrate inherited typological constants with locally driven transformations. This framework also establishes the basis for the reflection on conservation and management issues discussed in the following section (Section 5.4).

5.1. Morphological Genesis and Typological Structures of Vernacular Mosques

The mosques analysed are distinguished by their assertive formal sobriety, consistent with the principles of vernacular architecture. In all the specimens studied, the prayer hall appears to be the consistently constant element. It is square or rectangular in shape, with naves oriented parallel or perpendicular to the qibla wall. What distinguishes the mosques studied from the proposed model is the courtyard: although it is one of the central elements of the canonical configuration, it is absent or marginally represented in several cases. This discretion has led to the identification of a dominant morphological feature, structured according to a topological order in which the prayer hall is the central and constant element, while the other components vary according to local constraints and adaptation logic (

Table 3. Spatial Composition and Typo-Morphological Characteristics of Precolonial Mosques in the Djebel Amour.

Reference model
Period	Precolonial period (11th–19th) centuries
Mosques codes	S1	S2	S3	S4	S5
Mosques plans
Composition and Decomposition of mosques
Morphological components			Prayer hall
	X	X	X	X	X
			Courtyard
	/	/	/	X	/
			Portico
	X	/	/	X	X
			Minaret
	/	/	/	/	/
Type of prayer hall	Deeper than wide/aisles perpendicular to the Qibla wall	wider than deep/aisles perpendicular to the Qibla wall	Square	Wider than deep/aisles parallel to the Qibla wall	Wider than deep/no aisles
Variables/Criteria	Topological relationship (prayer hall/courtyard)
	No courtyard (Absence)	No courtyard (Absence)	No courtyard (Absence)	The courtyard on one side of the prayer hall (Adjacency)	No courtyad (Absence)
	Absence/presence of the portico
	Portico is in front of the entrance to the prayer hall (Presence)	No portico (Absence)	No portico (Absence)	Portico is in front of the entrance to the prayer hall (Presence)	Portico is in front of the entrance to the prayer hall (Presence)
	Number and position of the minaret in relation to the mosque
	No minaret (Absence)	No minaret (Absence)	No minaret (Absence)	No minaret (Absence)	No minaret (Absence)

Note: in the case of S1, S4 there is no minaret section but there is a staircase leading to the terrace.

and

Table 4. Spatial Composition and Typo-Morphological Characteristics of Colonial-Era Mosques in the Djebel Amour.

Reference model
Period	Colonial period (19th–20th) centuries
Mosques codes	S6	S7	S8	S9		S10
Mosques plans
Composition and Decomposition of mosques
Morphological components			Prayer hall
	X	X	X	X		X
			Courtyard
	/	/	X	/		/
			Portico
	/	X	X	X		/
			Minaret
	/	X	/	X		/
Type of prayer hall	Wider than deep/aisles parallel to the Qibla wall	Square	Wider than deep/aisles parallel to the Qibla wall	Wider than deep/aisles parallel to the Qibla wall		Wider than deep/aisles parallel to the Qibla wall
Variables/Criteria	Topological relationship (prayer hall/courtyard)
	No courtyard (Absence)	No courtyard (Absence)	The courtyard is superimposed onto the prayer room (Superposition)	No courtyard (Absence)		No courtyad (Absence)
	Absence/presence of the portico
	No portico (Absence)	Portico is in front of the entrance to the prayer hall (Presence)	Portico is in front of the entrance to the prayer hall (Presence)	Portico is in front of the entrance to the prayer hall (Presence)		No portico (Absence)
	Number and position of the minaret in relation to the mosque
	No minaret (Absence)	Minaret is outside of the entire mosque with two minarets	No minaret (Absence)	Minaret on one side of the entire mosque with one minaret		No minaret (Absence)
Period	Colonial period (19th–20th) centuries
Mosques codes	S11	S12	S13		S14
Mosques plans
Composition and Decomposition of mosques
Morphological components			Prayer hall
	X	X	X		X
			Courtyard
	/	/	/		/
			Portico
	/	/	X		/
			Minaret
	/	/	/		/
Type of prayer hall	Wider than deep/aisles parallel to the Qibla wall	Square	Wider than deep/aisles perpendicular to the Qibla wall			Wider than deep/aisles perpendicualr to the Qibla wall
Variables/Criteria	Topological relationship (prayer hall/courtyard)
	No courtyard (Absence)	No courtyard (Absence)	No courtyard (Absence)			No courtyad (Absence)
	Absence/presence of the portico
	No portico (Absence)	No Portico (Absence)	Portico is in front of the entrance to the prayer hall (Presence)			No portico (Absence)
	Number and position of the minaret in relation to the mosque
	No minaret (Absence)	No minaret (Absence)	No minaret (Absence)			No minaret (Absence)

Note: in the case of S11 there is no minaret section but there is a staircase leading to the terrace.

).

5.1.1. The Courtyard (Sahn): Absence, Marginality, and Contextual Adaptations

The widespread absence of courtyards in most specimens (S1, S2, S3, S5, S6, S7, S9, S10, S11, S12, S13 and S14) is due to a series of morphological, urban and socio-political constraints. In quantitative terms, this absence concerns approximately (86%) of the Djebel Amour corpus, confirming that the sahn is not a structuring typological constant in this region (

Table 5. Comparative Distribution of Courtyard and Portico Components Across Mosque Typologies.

Region/Corpus	Total Mosques	Courtyard Presence (Count)	Courtyard Presence (%)	Portico Presence (Count)	Portico Presence (%)
Djebel Amour	14	2	14.3%	7	50%
Souf	5	3	60%	4	80%
Al-Khabra (Saudi)	2	2	100%	2	100%
Erbil (Iraq)	5	5	100%	4	80%
West Sumatra (Indonesia)	25	24	96%	Not applicable	—

). Two major factors can therefore be identified to explain this configuration (Table 3 and Table 4), which correspond, respectively, to socio-political organisation and spatial density.

The first factor is related to the socio-political organisation of the ksour in the region studied, marked by the tribal fragmentation of local communities. Unlike the dominant Saharan models, where a central mosque structures the urban fabric, the ksour of Djebel Amour are characterised by the coexistence of several mosques within the same fortified complex. Each faction or subgroup tends to build its own mosque, as a means of asserting its identity and internal autonomy.

This configuration is evident in the ksar of Laghouat, where six mosques—El-Atik, Khalifa (or Ahlaf), Abdelkader Djilali, Taouti, Chadouliya and Safah—are spread across the districts of Ouled Serghine and Ahlaf; in the ksar of Taouila, where the Ouled Saci and Ouled Turki mosques reflect the organisation by lineage groups; and in the ksour of Aïn Madhi and Tadjmout (Figure 7).

This spatial fragmentation has a direct impact on architectural layout: the inclusion of a courtyard becomes secondary, or even incompatible, with a layout that is often constrained by the cramped nature of the ksourian fabric and the desire of each group to have its own independent mosque. Comparable phenomena have been reported in other Saharan and vernacular contexts, confirming that this adaptation is not isolated. Zerari [22] notes that in the Souf region, many mosques lack courtyards because the harsh open environment substitutes for them, especially in dense or isolated settlements. Quantitatively, about (40%) of Souf mosques include a courtyard—slightly higher than Djebel Amour but similarly illustrating a typology where the sahn is not essential.

This tribal dynamic is also reflected in the naming system for mosques, which is a powerful symbolic marker. Mosques are generally named after the group or neighbourhood to which they belong: El Atik (Ouled Serghine S3), Ahlaf (S9), Ouled Saci (S5) or Ouled Turki (S10). Others refer to a spiritual figure, such as Sidi Bouzid (S1) or Abdelkader Djilali (S8), associated with the Qadiriyya brotherhood. These names are not simply geographical or religious designations, but reflect relationships of power, filiation and territorial authority.

When a mosque is linked to a marabout figure, its proximity to a mausoleum or shrine further reinforces its symbolic importance. In addition, the frequent use of the name “El-Atik” in several ksour—Laghouat, Aïn Madhi, Tadjmout, Tadjrouna and Houaita—deserves special attention. This term, often attributed to the first mosque built in the urban area, sometimes refers to the only place of worship, without implying hierarchical centrality. Whether isolated or not, the El-Atik Mosque performs all major ritual functions and enjoys complete religious authority. Unlike the hierarchical structures found in the Algerian Sahara, each mosque in Djebel Amour functions as an autonomous Djamaa, with no distinction of rank.

The second factor concerns the density of urban fabric. The ksour in the region studied have compact layouts and narrow plots, which limit the possibility of integrating open spaces within mosques. The small size of these buildings reflects both the constraints of the available plots and the limited capacity required by tribal fractions. This trend corresponds to patterns observed in Ibadi mosques of M’zab, Djerba and Oman, where nearly 100% include courtyards, but their spatial distribution is articulated through fragmented voids and passageways rather than large unified sahn [77]. Similarly, Ghanbari [18] notes that in West African mosques of Futa Toro and Burkina Faso, courtyards are significantly reduced or replaced by shaded porches—often present in less than 40% of the documented cases, confirming that climatic pragmatism frequently prevails over canonical design.

Additional comparative evidence comes from traditional and historical mosques outside the Saharan sphere. In Erbil (Iraq), recent documentation shows that courtyards remain systematically present in traditional mosques (nearly 100%) reflecting both the availability of space in older neighbourhoods and the persistence of the canonical Middle Eastern typology. Likewise, in West Sumatra (Indonesia), a typological survey of 25 historical mosques reports courtyard presence in approximately (96%) of cases, demonstrating the strong endurance of the sahn in Southeast Asian wooden-roof traditions. These contrasts highlight the singularity of Djebel Amour, where environmental constraints and ksourian density override the canonical typological model that remains dominant in Erbil and Indonesia (Table 5).

• Exceptional contextual cases involving courtyard presence:

Although the courtyard is absent in the vast majority of Djebel Amour mosques, two exceptional configurations—representing around (14%) of the corpus—introduce significant and context-driven variations in the local typology (Table 5). These cases illustrate how the sahn can reappear when ritual, functional, or historical conditions outweigh the spatial constraints of the ksar.

Case 1: The Al-Atik Mosque in Ksar Tadjmout (S4):

This pre-colonial mosque contains a small utilitarian courtyard with a central well used for ablutions (Table 3; Figure 7). Despite the density of the surrounding fabric, the ritual importance of water-related practices justified maintaining an open-air space. This configuration echoes the role of the courtyard in the Great Mosque of Djenné (Mali), where Khalid [20] observes that the open space serves climatic and communal roles more than compositional ones.

Case 2: The Abdelkader Djilali Mosque in Ksar Laghouat (S8):

Built during the colonial period, this mosque is the only two-storey example in the region and integrates an upper-level courtyard terrace used for prayer, Qur’anic teaching, and study (Table 4; Figure 8). This vertical reinterpretation of the sahn reflects the combined influence of colonial restructuring and the growing liturgical needs of the community. Comparable reinterpretations occur in Al-Khabra (Saudi Arabia), where Alghafis & Sibley [19] identify semi-open platforms (sarha) fulfilling climatic and social roles analogous to courtyard functions.

This multifunctional spatial organisation–divided between religious, educational and community functions–marks a significant break with the reference model used for this study and illustrates an architectural evolution adapted to the constraints of the urban fabric of Djebel Amour. The analysis of this atypical configuration opens the way for a reflection on the impact of the colonial context on local architectural forms, showing how adaptation became a response to constraint.

The genesis of this mosque coincides with a pivotal moment in the urban and religious history of the region under study. The colonial period brought profound changes in the use and typology of existing mosques. Some, such as El-Dalaâ, Chettit, and Sidi Moussa (Djamaa El-Gharbi), were destroyed. Others, such as the El-Atik Mosque in Taouila, experienced gradual deterioration. In Laghouat itself, the El-Atik Mosque was requisitioned in 1855 to be converted into a military warehouse as part of the construction of Fort Bouscaren, before later being transformed into a church. This decision provoked strong local opposition, leading to its eventual return to Muslim worship. The Khalifa (or Ahlaf) Mosque suffered a similar fate, used as a warehouse and later as a church in 1900, and was only reassigned for prayer in 1927, at the initiative of Khalifa Ferhat Djelloul.

This historical dimension is now more explicitly integrated into the typomorphological reading. The study not only distinguishes between pre-colonial and colonial phases but also demonstrates how historical transformations—such as colonial urban restructuring, religious reforms, and social change—directly influenced typological evolution. These factors explain the emergence of new spatial configurations, notably the appearance of a single-storey mosque with an upper courtyard terrace, which marks a distinct departure from the compact and horizontal vernacular model’s characteristic of the pre-colonial period.

It was against this backdrop of the gradual disappearance or conversion of vernacular mosques in the region that the Abdelkader Djilali Mosque (1872) was built. It responded to the growing need among the local population for an appropriate place of worship—made even more pressing by the fact that the two other mosques built at the same time, Taouti (1864) and Chadouliya (also known locally as the Drawich Mosque), were small and deemed inadequate. Although the Chadouliya Mosque is not included in the present corpus, as it has been completely rebuilt and no longer meets the selection criteria, its historical reference remains relevant to the typological discussion.

The vertical configuration of the Abdelkader Djilali Mosque, incorporating an upper courtyard terrace, thus appears as a direct architectural response to a combination of three constraints: the density of the urban fabric, the need for a mosque suited to a larger community, and the destructive or restrictive effects of colonialism on existing mosques.

This configuration, unprecedented within the Djebel Amour region, confers a unique typological identity upon this mosque. No other Saharan region in Algeria presents such a vertical adaptation associated with an elevated courtyard of liturgical use. This model reflects an exceptional local capacity to transform vernacular architectural vocabulary in response to historical and urban constraints, while maintaining a spatial identity specific to Djebel Amour.

In this sense, the colonial period did not merely alter the physical presence of mosques but also redefined their spatial logic, triggering a typological evolution in which vernacular identity merged with new volumetric and structural expressions particular to this region.

A final explanation for the absence of courtyards lies in the existence of rahbats, vast open spaces characteristic of Saharan ksour. These community gathering places, sometimes equipped with a well, fulfil certain functions traditionally associated with the mosque courtyard, notably ablution. They may be located near the mosque, be specifically dedicated to it (rahbat El-masjid), or occupy a central position in the ksar (tadjmaat). In some cases, each neighborhood of the ksar has its own rahba.

Thus, when neither the urban structure nor the plurality of mosques explains the absence of a courtyard, the presence of an adjacent rahba can play a substitute role, as shown in the cases of the Ouled Turki mosque in Taouila (S10) and the Houda Mosque in Tadjmout (S14), (Figure 9). These external gathering areas, when compared to the sarha spaces of Al-Khabra or the shaded porches of Futa Toro, highlight a shared logic across regions: the mosque’s open space is not fixed by typology but adapted to social practice and environmental constraint.

In summary, the absence or transformation of the courtyard—reaching 86% in Djebel Amour compared to 40% in Souf, less than 40% in West Africa, and nearly 100% in Erbil, Indonesia, and Ibadi contexts—illustrates how socio-political fragmentation, urban density, and environmental pragmatism collectively shaped a distinctive regional identity (Table 5). This identity is defined by architectural restraint, morphological intelligence, and a pragmatic reinterpretation of Islamic spatial norms.

5.1.2. The Portico: A Liminal Space of Vernacular Expression

In the mosques studied, the portico is an atypical element specific to the architectural context of Djebel Amour. It does not correspond to the canonical portico of Islamic religious architecture but has specific forms and functions, evolving between the pre-colonial and colonial periods (Table 3) and (Table 4). Quantitatively, the portico appears in around half of the Djebel Amour corpus (50%), confirming its status as a selective rather than systematic architectural component (Table 5).

This space can be likened to a skiffa, a term borrowed from traditional Maghreb architecture—particularly in Algeria, Tunisia and Morocco—which refers to an intermediate space between the exterior and the interior. Typical of ksour, the skiffa takes the form of a vestibule, airlock or access corridor leading to the courtyard or living areas, playing an essential role in preserving privacy by blocking direct views from the outside.

This spatial role resonates with the “sabat” galleries described by Zerari [22] in the Souf region—semi-open arcaded spaces that provide both social shelter and climatic protection. In Souf, porticos are present in the great majority of documented cases (about 80%), forming a strong contrast with Djebel Amour, where the portico tends to be closed and inward-looking. This configuration reflects the colder plateau climate and a more private architectural culture specific to the region.

It also acts as a climatic regulator by reducing draughts during hot periods and as acoustic insulation from outside noise [82], thus helping to maintain the desired calm in the prayer space. This connection with domestic architecture explains why, in most studied cases, the portico functions as a discreet transitional space rather than a monumental entrance.

In Aïn Madhi (S1), Tadjmout (S4) and Ouled Turki (S5), it takes the form of a covered passageway without arcades, morphologically similar to the traditional skiffa, and serves more to manage circulation than to monumentalise the entrance (Figure 10).

Such sobriety characterises the pre-colonial phase and reflects the intimate relationship between the mosque and its surrounding fabric. This feature is reminiscent of how certain rural mosques in North Africa favoured simple entrance structures inherited from vernacular housing rather than reproducing the canonical portico of large urban mosques.

Similar adaptive vestibules are found in West African mosques studied by Ghanbari [18], where narrow shaded corridors act as social thresholds. In these West African examples, such transitional elements are almost systematically present (close to 100%), reflecting the climatic need for shaded intermediate zones (Table 5). In the Great Mosque of Djenné, however, Khalid [20] shows that porticoes are deliberately absent, the massive earthen façade itself assuming the role of a monumental social threshold.

From the colonial period onwards, however, a gradual typological transformation of the portico can be observed (Table 3). In the mosques of Khalifa (S9) and Safah (S10), it widens and opens more, adopting characteristics closer to the canonical portico: a vaulted corridor with arcades. Such evolution parallels transformations observed in Al-Khabra (Saudi Arabia), where Alghafis and Sibley [19] describe al-Misbah and al-Eshah—semi-enclosed prayer and gathering zones that mediate between sacred and communal realms. Here again, the presence of such spaces is systematic (100%), illustrating a regional preference for semi-open thresholds (Table 5).

The case of Safah is particularly significant: this mosque is the only example in the region where the portico fully reflects the canonical configuration, with a corridor of pointed arches accessible by side staircases. Unlike pre-colonial examples, the portico also serves as a gathering and waiting area, sheltering worshippers before and after prayer and protecting them from the elements.

This evolution clearly coincides with the colonial period, when new spatial norms, patterns of urban exposure, and forms of social interaction fostered greater visibility and public accessibility of religious buildings. The portico thus shifts from a discreet climatic buffer to a more expressive social threshold, signalling both adaptation and resilience within the reconfigured colonial urban order.

Intermediate cases show a unique appropriation of the portico in the Ksar fabric. In Khalifa, for example, the portico is integrated into a gallery with semicircular arches, already present in the Ksar, and thus fulfils a dual function: public gallery and access space to the mosque. In the Mohamed El-Habib Mosque in Aïn Madhi (S13), the portico is enlarged to incorporate an additional social function: it becomes a vestibule where worshippers leave their shoes before entering the prayer hall (Figure 11).

However, the absence of porticos in some pre-colonial mosques (Sidi Bouzid S2, El-Atik in Laghouat S3) can be explained by the occupation of its location by functional annexes. This selective pattern is comparable to Erbil (Iraq), where porticoes appear in about 80% of traditional mosques, indicating that their presence depends less on typological doctrine than on climate, circulation, and spatial constraints (Table 5).

Thus, the formal and functional diversity of this liminal space reveals the logic of adaptative specific to the religious architecture of the ksour of Djebel Amour.

Overall, this typological evolution of the portico—from enclosed skiffa to open arcaded gallery—reflects the progressive hybridisation between vernacular practices and canonical Islamic models under the influence of colonial-era transformations. The mosques of Safah and Khalifa stand as the most representative examples of this shift, where local builders assimilated new spatial concepts while preserving regional identity.

This duality between adaptation and continuity distinguishes the Djebel Amour mosques from other Saharan regions of Algeria, where the canonical portico remained marginal or unaltered. In this sense, the portico becomes a key indicator of historical change, encapsulating how colonial pressures and local creativity together redefined the architectural language of vernacular mosques.

Across Saharan, Arabian, and Sahelian contexts, these transitional elements—skiffa, sabat, sarha, misbah—form a coherent typological family. The Djebel Amour variant stands out as the most introverted expression of this shared architectural language, uniting environmental intelligence, privacy, and communal symbolism.

5.1.3. Variability of Annexes and Spatial Integration

The earliest specimens in the corpus studied, like the founding mosques of the Islamic period, feature a sober layout centered primarily on the prayer hall. At this stage, there are no functional or secondary annexes. However, over time, and in response to the changing needs of communities, additional spaces were gradually integrated. These additions, whether functional or symbolic in nature, reflect a gradual adaptation to local realities, without calling into question the foundations of mosque architecture.

This section examines these additions as indicators of change. They take various forms, ranging from spaces intended for religious instruction or ritual preparation to commemorative annexes (Table 1). Their morphological diversity, their degree of integration into the overall composition, and their positioning in relation to the prayer hall illustrate the adjustments made to the canonical model in the Saharan context. Several examples (S2, S3, S4, S5, S6, S8, S9, S11, S13, and S14) reflect this dynamic. The integration of annexes differs from case to case and results from various environmental, social, or liturgical factors.

Ablution areas come in several configurations. Some are designed as closed rooms directly accessible from inside the mosque. Others rely on the use of wells, sometimes integrated into the courtyard, as in El-Atik Tadjmout (S4), or located in the immediate vicinity, as in Laghouat (S3) and Houaita (S11). In Sidi Bouzid (S2) and Abdelkader Djilali (S8), this function is provided by an adjoining hammam (Table 3 and Table 4). When no specific structure is present, the water needed for ablutions is drawn from a seguia, a collective irrigation canal running through the ksour (Figure 12).

These hydraulic networks are not limited to supplying religious spaces, but also irrigate agricultural land, homes and public spaces. Their use by the mosque demonstrates their harmonious integration into a water management system that is deeply rooted in local culture. In addition, some annexes have a memorial function. Several mosques are associated with mausoleums, usually linked to a religious figure or founder. In El-Atik Tadjmout (S4), a mausoleum is attached to the rear of the prayer hall, on the west side. According to oral and historical sources, it is attributed either to one of the imams or sheikhs associated with the mosque, to Ahmed Ganda, considered to be the builder, or to Kaddour Ben Baraka, the donor of the land. According to some accounts, the tomb was originally placed against the qibla wall before being moved during the 1979 extension. Today, it remains outside the prayer space but is integrated into the building. Other cases confirm this link between religious function and funerary memory. At the Mohamed El-Habib Mosque (S13), a mausoleum is located to the north of the prayer hall and houses the graves of members of the Tidjâni family. Other tombs are visible in the south wall of the hall. In Taouti (S6), the extension carried out in 1925 made it possible to integrate the tomb of the founder, Ahmed Ben Salem El-Taouti, giving the mosque an additional heritage dimension (Figure 13).

From this perspective, the annexes found in the vernacular mosques of Djebel Amour are not part of a fixed canonical structure but rather constitute adjustments that respond to the evolving needs of worship, the community, and the territory. Their integration, although variable, remains consistent with the spatial organisation of the mosques studied. They reveal architecture in continuous transformation, where sacred space adapts to local uses and memories, thus consolidating its roots in time and in the Saharan landscape.

The analysis in this first section shows that the prayer hall is the central core of the mosques of Djebel Amour, while the other components—courtyards, porticos, and annexes—adapt to the constraints of the local context. The compactness of the urban fabric of the ksour and tribal fragmentation explain the frequent disappearance of the courtyard, as well as the emergence of vernacular porticos, often inspired by the skiffa, rather than monumental forms. These characteristics reflect sober and functional architecture, comparable to other similar cases in arid regions, but enriched with original local solutions, such as courtyard terraces or hybrid porticos introduced during the colonial period.

5.2. Reinventing the Canon: The Minaret Between Eastern Traditions and Colonial Influences

In the Algerian Sahara, the minaret transcends its religious function to become a marker of identity and symbolism. However, its presence and morphology vary considerably from one region to another. Heirs to a vernacular architectural tradition characterised by sobriety and economy, Saharan minarets evolve according to spatial constraints, historical contexts and external influences.

In line with the reference model adopted for the horizontal analysis of mosques—comprising the prayer hall, courtyard, portico and minaret—this section focuses on the fourth element, the minaret, analysed this time according to its vertical dimension. The reference model distinguishes three main segments: the shaft (or tower), the gallery/balcony and the lantern (

Table 6. Typo-Morphological Characterisation and Chronological Evolution of Minaret Architecture in Djebel Amour.

Segmentation of the minaret architecture by Reference model
Period	Colonial period (19th–20th) centuries
Mosques and minarets codes	S7		S9
	M1	M2	M3
Segmentation of the minaret architecture in the Djebel Amour			/
	Note: Minaret M3 of Mosque S9—Presented as a figure due to insufficient data regarding its exact dimensions and architectural details.
Section and elevation showing the presence and absence of staircase of minaret
Variables/criteria of the minaret in the colonial period	Presence/Absence of the balcony/gallery (segment 2)
	Presence                                                  Absence                                           Presence
	Presence/Absence of the lantern (Segment 3)
	Presence                                                  Presence                                           Presence

). This grid allows us to compare the minarets of Djebel Amour with the canonical Maghreb models inherited from Kairouan and relayed by the mosques of M’Zab, but also with colonial forms, to highlight local specificities. While the Kairouan and Mozabite models are distinguished by their vertical monumentality and marked tripartite division, the mosques of Djebel Amour, on the contrary, favour modest and discreet solutions. It is within this contrast that the following analysis takes place: first, the pre-colonial heritage of architectural sobriety, then the colonial emergence of an unprecedented monumentality, where Cordovan influence is combined with European stylistic contributions.

5.2.1. Precolonial Legacies: Architectural Sobriety and Eastern Continuities

The minarets identified in Djebel Amour during the pre-colonial period follow a single dominant morphological logic: that of the staircase minaret. This type, directly inherited from the oriental prototype of the Amr al-‘As Mosque in Fustat, Egypt, is characterised by a staircase leading to the terrace–either located outside and accessible from the street, or integrated inside the mosque–topped by a small sentry box or lantern (souma’a) placed at the corner of the walls, which served as a shelter for the muezzin while completing the formal balance of the volume. Research on ancient Islamic architecture shows that this archaic model has been attested since the early centuries of Islam in mosques such as Buṣrā in Syria, where a flight of steps ran along the wall to the roof. This typology, initially Eastern, then spread to many peripheral regions of the Muslim world: the countryside of Egypt, central and western Anatolia, Libya (Ajdâbiyya), the Persian Gulf (Siraf), East Africa, Fulani mosques in West Africa, and Ibadite mosques in Jebel Nafusa, Djerba and Oman. It is also found in vernacular mosques in the Algerian Sahara, particularly in the Souf region, confirming the Eastern roots of this type of architecture in the Sahara (Figure 14). This broader Saharan continuity is further illustrated in Souf, where staircase minarets constitute the prevailing typology around 60% a proportion that reinforces the idea that these sober, non-monumental vertical forms were not an exception but rather a regional norm whose logic extended beyond Djebel Amour (

Table 7. Distribution of Staircase and Monumental Minarets Across the Comparative Regional Datasets.

Region	Total Mosques Considered	Staircase Minaret (Count)	Staircase Minaret (%)	Monumental Minaret (Count)	Monumental Minaret (%)
Djebel Amour	14	4	28.6%	3	21.4%
Souf	5	3	60.0%	0	0%
Al Khabra (Saudi Arabia)	2	0	0%	2	100%
Erbil (Iraq)	5	0	0%	0	0%

). Within the study area, the precolonial presence of staircase minarets represents approximately 28.6% of the corpus, a figure that underscores both their functional nature and their selective, non-systematic use. By situating the Djebel Amour corpus within this wider lineage, it becomes clear that the staircase minaret operated less as a stylistic choice than as a shared architectural language inherited from early Islamic practices and adapted to local constraints.

In the vernacular mosques studied in Djebel Amour, both the pre-colonial and colonial periods are marked by a near absence of minarets, replicating the configuration of the first mosques of Islam. Several examples from the corpus confirm this morphological logic, such as El-Atik in Aïn Madhi (S1), El-Atik in Laghouat (S3), Taouti (S6), Abdelkader Djilali (S8), Ouled Turki (S10), El-Atik of Tadjrouna (S12), Mohamed El-Habib (S13) and Houda of Tadjmout (S14).

The absence of minarets in these mosques in the pre-colonial period can be explained by several contextual factors. The El-Atik mosque in Aïn Madhi (S1), one of the oldest in the region, echoes the spirit of the Prophet’s mosque in Medina: devoid of any vertical features, it favored a sober and communal religious practice, where the call to prayer could be made from the terrace or even from a neighboring house, following the example of Bilal, Islam’s first muezzin. The El-Atik Mosque in the ksar of Laghouat (S3) illustrates another situation: tribal fragmentation and integration into a group of several mosques meant that it did not require a highly visible minaret. Although there are no written sources confirming the existence of a minaret at that time, it is likely that a simple staircase provided access to the terrace for the adhan, as was the practice in other Saharan ksour.

These observations bear similarities to the Ibadite mosques of Djerba and Oman [77], where the minaret, when present, remains a secondary functional element: it serves as a platform for the call to prayer, can play a defensive role on occasion or express a symbol of authority, but is not intended to be monumental. Ultimately, the absence or discreet nature of the minaret in the pre-colonial mosques of Djebel Amour reflects a dual anchoring: on the one hand, in the architectural practices inherited from the early centuries of Islam; on the other hand, in the adaptation to the compact ksourian fabric, where the multiplicity of mosques made visual affirmation through vertical forms unnecessary.

When minarets first appeared in pre-colonial times, they exclusively adopted the staircase minaret style, inherited from the Eastern prototype. The El-Atik Mosque in Sidi Bouzid (S2), dating from the 12th century, is the first identified example: an external staircase, built against the wall, provided access to the terrace. Over time, a small sentry box was added to protect the muezzin, who could then call the adhan either from the terrace or from this shelter. In the 16th and 17th centuries, the same logic was found at the El-Atik Mosque in Tadjmout (S4), then in the 19th century at the Ouled Saci Mosque (S5). In both cases, the staircase is integrated into the interior, either on the side opposite the prayer hall or in line with the qibla so that the muezzin does not turn his back on this sacred direction when calling to prayer, as in Ibadite mosques [81]. This typology spread during the colonial era: the reconstruction of the El-Atik Mosque in Houaita in 1936 illustrates the continuity of this model, with an external staircase located to the south of the complex (Figure 15).

Similar designs can also be seen in the Ibadite mosques of Djerba and southern Tunisia, where the minaret staircase, often accessible from the street, had a strictly utilitarian function for the call to prayer, with no monumental purpose (Figure 15).

5.2.2. Colonial Period: The Selective Emergence of Monumentality

The colonial period marked a decisive break in the evolution of the mosques of Djebel Amour. For the first time, the minaret emerged as a vertical landmark, signalling both a typological transformation and a symbolic redefinition of religious presence within the restructured colonial cityscape. Unlike the prototype in Kairouan and its extensions in M’Zab—characterised by a superimposed tripartite structure and a strong sense of monumentality—the colonial minarets of Djebel Amour adopted a morphology closer to the Cordoba model, based on two clearly differentiated volumes. This Cordovan influence, inspired by the minaret of the Qarawiyyin in Fez and already relayed by Maghreb adaptations such as the Qala of the Beni Hammad, finds a unique expression here. This shift reflects not only an aesthetic adaptation but also the translation of colonial urban visibility into the language of religious architecture, as evidenced in (Table 6) and (Figure 16).

A broader comparative perspective helps situate this shift. In Al-Khabra (Saudi Arabia), mosques also present monumental minarets (100%), yet with a morphology radically different from that of Djebel Amour: compact volumes, thick walls, and truncated pyramidal silhouettes typical of Najdi architecture. Their monumentality is therefore climatic and constructive rather than symbolic or urban, unlike the colonial Algerian model, which prioritises visual dominance and façade symmetry. By comparison, in Djebel Amour, monumental minarets remain exceptional, appearing in only about 21.4% of the corpus. This limited quantitative presence shows that vertical assertion was adopted selectively and mainly under colonial influence, rather than emerging as a natural extension of local vernacular traditions. Taken together, these contrasts demonstrate that monumentality in Islamic architecture is not tied to a single typology, but emerges from diverse contextual negotiations—colonial, regional, or environmental (Table 7).

The Safah Mosque (S7) is a unique and emblematic example. Built between 1865 and 1874 on the ruins of the residence of Khalifa Ahmed Ben Salem, it owes its name to the large rock (al-safiha) that served as the foundation for the building. Known both as the “Great Mosque” and the “Souma’a Mosque”, it was the first in the region to have a minaret, marking a clear break with the discretion of pre-colonial mosques. This vertical assertion introduced a new spatial hierarchy within the dense ksourian fabric, where height began to function as a marker of religious and political visibility.

Its builder, Italian Giacomo Molinari, commissioned by the colonial administration, converted to Islam during the construction of the mosque, taking the name Si Ahmed. His work was part of an urban transformation policy undertaken by the colonial authorities, alongside the construction of other buildings in the region.

From an architectural point of view, the Safah Mosque illustrates a stylistic hybridisation: its slender composition, pointed arches and decorative vocabulary evoke influences from Gothic architecture, while the use of green and white triangular zellige tiles refers to Mozarabic influences adapted to local materials. This combination creates a monumentality unprecedented in the Ksourian fabric and fuels the hypothesis of an ambiguous initial purpose: some clues suggest that it may have been designed as a church, before being reinterpreted as a mosque to ease tensions linked to the destruction or conversion of neighboring mosques (El-Atik and Khalifa), as mentioned above.

The ogival dome, visible in old photographs (Figure 17), has now disappeared. Its collapse was probably due to its structural fragility, linked to a slenderer shape than traditional hemispherical domes, accentuated by Saharan climatic conditions (sand-laden winds, temperature variations) and insufficient maintenance, further exacerbated by empirical interventions. All these factors led to a gradual weakening of the supports, until they collapsed.

The most striking feature, however, remains the presence of two minarets (M1 and M2), a configuration that is unique in the entire Djebel Amour region. The main minaret, located to the west, rises to a height of 30 m; it is accessible via a stone spiral staircase leading to the terrace and upper balcony, and is topped by an octagonal lantern—although early representations indicate a quadrangular shape.

The second minaret, which is 17 m lower and has no staircase, plays an essentially symbolic and decorative role, reinforcing the symmetry of the facade and the monumentality sought by colonial aesthetics. These two towers break with the Maghreb rule of uniqueness and reflect a desire for visual and political affirmation. The main minaret serves a ritual function (calling the faithful to prayer from the terrace or balcony), while the second reinforces the visual presence of the complex, as confirmed by its lack of a balcony (Table 6). This dual arrangement underscores the dual narrative of the period: a vernacular society reasserting its faith through inherited forms, and a colonial authority imposing monumental symmetry as an instrument of urban control.

The architectural language of the Safah minaret was disseminated and reinterpreted in that of the Khalifa Mosque (M3). A photograph dated 1892 shows the Khalifa Mosque being used temporarily as a church, as revealed by the cross placed on its dome (Figure 18). This transformation preceded the construction of Saint Hilarion Cathedral around 1900, before the building was converted back into a mosque in 1927 (Figure 19). These elements confirm that the Safah Mosque was the first mosque with a minaret in the Djebel Amour region. The Khalifa Mosque, on the other hand, did not have a minaret in its original state; the tower that was added during the colonial period was primarily a Christian symbol, echoing the verticality characteristic of churches.

However, two other photographs, dated 1944 and 1956, respectively, attest to the presence of this tower as a minaret integrated into the mosque (Figure 18). Although it echoes the slender silhouette and general layout of Safah, it differs in its more massive morphology, stylistically different couplet and soberly treated merlons. Such reinterpretation indicates a process of typological negotiation rather than imitation: local builders appropriated the colonial monumental language while re-inscribing it within the functional and symbolic codes of Islamic architecture. This morphology has also spread to the sub-prefecture of the region (Figure 19), reflecting a local adaptation of the colonial monumental model to a Ksourian setting.

Today, this minaret has been demolished and rebuilt (Figure 18), but it reveals, along with the two minarets of Safah, a common logic: all three adopt a morphological organisation in four segments—base, shaft, gallery and lantern (Table 6).

Moreover, this same morphological pattern continued to influence later constructions, notably in the Amir Abdelkader Mosque, built in the 21st century, where the vertical composition and volumetric balance of the Safah model remain clearly recognizable (Figure 19).

This composition clearly distinguishes them from the reference model adopted in this study, which is limited to three parts, and highlights a colonial desire to assert monumentality. Their location also reflects different approaches: symmetrical and ostentatious on the main facade in Safah, more discreet and relegated to the rear of the building in the case of Khalifa (Table 4).

A similar dynamic can be observed in the Souf region [22], albeit in different ways. The Sidi Salem Mosque features a single monumental minaret, inspired by the model in Kairouan, thus echoing the monumental style of Safah. In contrast, the Sidi Massoud Mosque is distinguished by its multiple staircase-type minarets, reflecting a desire to assert status. Although the typology differs, the approach is like that of the Safah Mosque in terms of the idea of visually enhancing the symbolic power of the site.

The absence of minarets in certain mosques from this period can mainly be explained by the functional priorities of the population, which focused solely on the practice of prayer. This is the case, for example, with the Taouti Mosque (S6), built in 1864–before the Safah Mosque (S7)–as well as the Chadouliya Mosque (1864) and the Abdelkader Djilali Mosque (S8), where the inner courtyard appears to be a more essential component than the minaret. This configuration finds a meaningful parallel in the historical mosques of Erbil (Iraq), where Mustapha and Ismael [11] show that architectural attention was concentrated primarily on the courtyard and the longitudinal corridor, rather than on vertical structures such as minarets (Table 7). In this corpus, the minaret plays a marginal or even absent role, confirming that typological and morphological identity relied more on spatial organisation than on vertical signalling. The Erbil examples therefore illustrate, like Djebel Amour, that many historical mosques developed strong architectural identities without relying on a minaret, especially when liturgical circulation, climatic control, and spatial hierarchy were ensured through courtyard-centred and corridor-based compositions.

In other contexts, such as the Ouled Turki Mosque (S10) or the Houda Mosque (S14), although built later, the pre-colonial logic is continued with staircase minarets like those of the Ouled Saci Mosque (S5) or El-Atik Mosque (S4). In the specific case of the Mohamed El-Habib Mosque (S13), monumentality is ensured not by a minaret, but by a dome located inside the prayer hall. This choice reflects a desire to visually mark the worship space, as in certain examples in Souf [22], where the dome fulfils an identity and symbolic role like that of the minaret (Table 4).

Ultimately, the evolution of the minaret in Djebel Amour (Table 6) reveals a clear typological continuum. In the pre-colonial period, the dominant model remained the staircase minaret (present in about 29% of the corpus) and aligned with broader Saharan and Eastern traditions, as illustrated in Souf (60%), Ibadi regions, and several West African cases. This confirms that sobriety and functional verticality were the prevailing regional norms, while the absence of minarets in many Djebel Amour mosques was neither exceptional nor anomalous (Table 7).

The colonial period introduced a contrasting dynamic, marked by the selective emergence of monumental minarets (≈21%) in Safah and Khalifa. Although limited in number, these new vertical forms redefined visibility and symbolically reshaped the ksourian landscape. Their morphology—two-part composition, façade emphasis, and aesthetic display—differs markedly from other regional models: the compact Najdi minarets of Al-Khabra (Saudi Arabia, 100%), the functional horizontal logic of Erbil’s historical mosques, and the stratified roof systems of West Sumatran mosques (Table 7).

Viewed together, these comparisons show that the Djebel Amour minaret is the product of successive adaptations: Eastern continuity, Saharan pragmatism, and colonial reinterpretation. Rather than signalling rupture, this sequence reflects a process of hybridisation through which vernacular identity absorbed external influences while maintaining its own architectural coherence. This distinctive trajectory sets Djebel Amour apart within the wider typological landscape of Saharan religious architecture.

5.3. Vernacular Construction Systems and Materials

The study of construction systems and materials is not a primary aim of this research, but rather an essential complement to understanding the vernacular character of the mosques of Djebel Amour. These buildings, the legacy of expertise passed down from generation to generation, derive their authenticity from the use of local materials–stone, adobe and T’mechent–worked by craftsmen and ingeniously integrated with the constraints of the Saharan environment. Their role goes beyond the purely technical: they shape forms, ensure social cohesion through collective maintenance practices, and contribute to the heritage value of an architectural ensemble deeply rooted in its territory.

5.3.1. Local Materials and Traditional Craftsmanship

The mosques of Djebel Amour are characterised by a high degree of homogeneity in the choice of materials, mainly stone and adobe, supplemented by lime and traditional plasters. These resources, extracted and processed locally, bear witness to the continuity of the expertise provided by the Maallemin of the local ksour, who made adobe and lime in traditional workshops and kilns (Figure 20). Adobe, made from local clay moulded and dried in the sun, dominates in the mosques of Laghouat (S3, S6, S7, S8, S10) and Tadjrouna (S12). Stone, on the other hand, is widely used in the mosques of Houaita (S11), Tadjmout (S4 and S14), Taouila (S5, S9), Aïn Madhi (S1) and Sidi Bouzid (S2), (Figure 20).

Two main construction techniques are observed. The first, characteristic of Aïn Madhi, is the “wheat ear” technique, consisting of arranging stones so that their edges form a 45° angle—or sometimes right angles—creating a distinctive pattern traditionally used to stabilise walls (Figure 21). Unique to Djebel Amour and absent from other Saharan mosque architectures, this technique exemplifies the ingenuity of local craftsmen in responding to structural and climatic constraints. It reveals how indigenous material knowledge contributed to the durability and identity of these religious buildings.

The second, more widely used in the mosques studied, is the ‘mixed’ technique, it is based on the use of irregularly shaped stones carefully adjusted to the available space. The gaps between the blocks are filled with a mortar specially prepared for this purpose, ensuring the cohesion and stability of the whole (Figure 21).

Wall surfaces are protected by various coatings, mainly based on lime, sand or plaster. In addition, T’mechent, a traditional mortar composed of earth and plant fibres, is used, particularly in Ouled Saci and El-Atik de Laghouat. In the latter case, its originality lies in the integration of local gypsum, used in arches and entrances. This process, also found in the architecture of M’zab (Ghardaïa), illustrates the ingenuity of Saharan builders in adapting materials to climatic and structural constraints.

As with architectural forms, materials have undergone certain changes. The Safah Mosque is a representative example: it combines cut stone for foundations, stairs and corners, sun-dried adobe for walls, and fired brick for the cylindrical columns, pillars, vaults and pavements. This diversity reflects successive practices oscillating between tradition and modernity, without departing from local construction logic.

5.3.2. Traditional Flooring and Load-Bearing Structures

Floors and roofs display strong uniformity, with local variations. They are generally supported by main wooden beams—palm, willow, or juniper—combined with secondary elements such as palm ribs (j’rid) or reed mats. This assembly is then covered with clay or sand, sometimes reinforced with lime to improve waterproofing (Figure 22).

At Sidi Bouzid (S2), the floor rests on main willow beams and secondary juniper beams, covered with clay, with a recent innovation: the use of aluminium foil to reinforce waterproofing. At Ouled Turki (S9) and Tadjmout (S5), the system combines willow and juniper beams, reed mats, and a clay or sand covering reinforced with lime. The mosque at Ouled Saci (S5) is distinguished by its use of T’mechent in the covering, enhancing structural cohesion, later complemented by a plaster layer that visually homogenises the interior surface.

In the prayer hall, these floors rest on load-bearing pillars whose shape and technique vary depending on the building. In most of the configurations studied, they appear quadrangular and built of adobe, while in Tadjmout (S4) and in Houaita (S11) cylindrical stone columns can be seen. A unique case is that of the El-Atik Mosque in Laghouat, where the pillars have different volumes and dimensions from one point to another in the prayer hall. This irregularity, which remains unexplained, calls for in-depth archaeological studies to better understand the processes used. The Sidi Bouzid Mosque is also notable for its complete absence of arches: the pillars associated with the beams of the traditional ceiling directly ensure the stability of the roof, a sober but distinctive solution (Figure 23).

The analysis of these constructive choices reveals an implicit environmental awareness deeply rooted in local traditions. The use of stone, earth, and lime ensures both structural stability and natural thermal regulation, making these mosques inherently well-adapted to the semi-arid climate. In this perspective, recent studies on vernacular architecture emphasise that such material and formal solutions often reflect embedded sustainable logics, where resource economy and climatic adaptation are inseparable [99]. The Djebel Amour mosques align clearly with this dynamic, illustrating an early form of sustainability in which environmental intelligence and typological coherence remain closely interdependent.

5.4. Conservation and Management of Transformations in the Mosques of Djebel Amour

Beyond morphological and typological analysis, this section examines how the findings of the study can inform contemporary strategies for conserving and managing the transformations of mosques in Djebel Amour.

Although the typomorphological approach was initially applied to reconstruct the original state of these buildings, its scope extends beyond simple historical documentation. By identifying the typological and morphological constants and variations that define their architectural identity—such as the configuration of the prayer hall, the absence or marginality of the sahn, the volumetric sobriety, and the use of local materials—this study establishes a scientific reference model capable of guiding current preservation practices. The analysis of the original state thus becomes a comparative framework for assessing later interventions and distinguishing between authentic continuity and inappropriate alteration.

Over the past decades, several mosques in the region have undergone partial extensions, mainly enlargements of the prayer hall to accommodate the growing number of worshippers. These transformations, often initiated by local communities, testify to the living and adaptive nature of this religious heritage. The study shows that such developments can be interpreted not as ruptures with tradition, but as coherent extensions, provided that they respect the inherited architectural grammar. An intervention becomes acceptable when it reproduces the original constructive logic while maintaining the proportions, wall thickness, and formal sobriety characteristic of the initial volumes. When these conditions are met, the visual distinction between old and new expresses a legible continuity rather than a dissonance.

However, field observations reveal that not all interventions meet these criteria. In certain cases—such as the Sidi Bouzid Mosque, the El Atik Mosque in Laghouat, the Abdelkader Djilali Mosque, the Ouled Turki Mosque, and the Al-Atik Mosque in Tadjrouna—modern materials or forms alien to the vernacular vocabulary have been introduced (Figure 24). Although driven by functional and communal needs, these operations have sometimes altered the volumetric balance and structural coherence of the original buildings, partially disrupting typological continuity. These examples highlight the need for a clear, scientifically grounded reference framework to guide future transformations and ensure their compatibility with the architectural characteristics identified through typomorphological analysis.

Building upon this diagnostic, the study evolves from an analytical tool into a methodological framework for long-term conservation and management. It supports the principle of controlled extension, in which contemporary interventions are guided by typological coherence and material compatibility. The objective is not to freeze the mosques in their original state, but rather to accompany their evolution while safeguarding their morphological and constructive invariants. This scientifically informed logic reconciles the preservation of architectural identity with the functional adaptation of mosques to present-day needs.

Within this perspective, the database resulting from this study plays an essential operational role. By systematising morphological, typological, and structural observations, it extends analytical research into the domain of heritage management, providing tools for informed and preventive conservation. This database—an authentic scientific synthesis of the corpus—constitutes a key instrument for the sustainable management of Djebel Amour mosques. By organising information on forms, structures, materials, and vernacular techniques in a structured manner, it enables the identification of the architectural constants that underpin each building’s identity.

This systematic knowledge of original configurations and construction logics provides a baseline reference for any future intervention—whether maintenance, restoration, or extension. It also serves as a benchmark for evaluating recent or forthcoming transformations, measuring their degree of coherence with the original forms and materials. In this sense, the research transcends academic documentation to become an operational tool for sustainable heritage management, linking architectural analysis to contemporary conservation practice.

Beyond documentation, the study proposes an applied methodological framework that integrates typological, material, and social dimensions. This multi-scalar approach provides a reference model for the preservation and adaptive reuse of vernacular mosques in similar Maghrebi contexts, ensuring both authenticity and continuity of architectural identity.

The proposed database is directly supported by the photogrammetric documentation developed in Section 4.1.1. The 3D models, point clouds, and orthophotos generated through Agisoft Metashape constitute measurable and georeferenced datasets that can be continuously updated and used for monitoring the conservation state of the mosques.

In future developments, this database could be expanded into a broader digital documentation programme encompassing all vernacular mosques in the region. Such an initiative could combine complementary techniques—including drone-based photogrammetry, 3D laser scanning, and LiDAR surveying—to achieve high-precision records and extend the spatial coverage of the corpus. These methods would enhance the accuracy, interoperability, and accessibility of the recorded data, linking the morphological and typological parameters identified in this study to spatial and visual information layers.

This integration of photogrammetric, laser, and geospatial datasets within the conservation framework would ensure not only the precision of recorded information but also its long-term applicability in the digital management of built heritage. Such a framework would align the Djebel Amour documentation with international standards of digital conservation (UNESCO, ICOMOS) and bridge analytical documentation with preventive conservation, through the use of accessible, scalable, and interoperable digital tools.

6. Conclusions

This study examined fourteen vernacular mosques of the Djebel Amour region, spanning pre-colonial to colonial periods, to reconstruct their morphogenesis and reveal the architectural logic guiding their evolution. Through a typo-morphological approach integrating field surveys, archival documentation, iconographic materials, and oral testimonies, this research identified both enduring typological constants and adaptive transformations shaped by environmental and social conditions.

The findings confirm the centrality of the prayer hall with its mihrab as the compositional core, while other components—courtyards, porticos, and annexes—display contextual variability. The emergence of skiffa-inspired porticos, staircase minarets, and selective monumentalisation during the colonial period illustrates the capacity of the Saharan religious architecture to integrate external influences without losing its vernacular essence. The constructive dimension, rooted in local materials and craftsmanship, reinforces the environmental intelligence and cultural continuity of this corpus.

Beyond morphological interpretation, this research provides a methodological basis for heritage conservation and transformation management. By identifying typological constants and constructive logics, it proposes criteria for evaluating current interventions and guiding restoration or extension projects. This framework supports the reconciliation between preservation and contemporary use, ensuring that future transformations respect inherited architectural values while meeting evolving community needs.

Ultimately, the Djebel Amour mosques stand as living models of contextual adaptation and architectural coherence. Their study not only fills a historiographical gap but also offers practical tools for sustainable heritage management. By linking typomorphological analysis with emerging digital technologies—notably photogrammetry, geospatial modelling, and metric documentation—this research strengthens the scientific foundations needed for evidence-based conservation strategies. It also demonstrates that the vernacular architecture of Djebel Amour exemplifies forms of adaptive intelligence comparable to those observed across wider African, Middle Eastern, and Southeast Asian mosque traditions, particularly in regions where environmental constraints, material availability, or tribal social structures shape the religious space. This broadened perspective situates the Djebel Amour corpus within contemporary international debates on vernacular resilience, sustainability, and digital heritage. As such, the region emerges as a relevant reference model for future comparative research and for the preservation of vernacular religious architecture in arid and culturally stratified contexts.