Spatial Configuration of Traditional Dwellings in Riyadh Al-Khabra Traditional Town, Saudi Arabia

Traditional buildings, particularly residential dwellings, are spatio-temporal reflections of the society and culture in which they were originally sited. Understanding the nature of this built heritage thus fosters interpretation of pre-vious generations’ experiences in these older settlements, all of which can thus be described as products of several different cultural dimensions. Qassim province, which sits in the central province of the Kingdom of Saudi Arabia, is distinguished by having retained various traditional towns and villages, including multiple dwellings representing important eras in the past. However, due to the local population’s abandonment of these traditional towns and movement to new urban areas, and related failures in conservation and restoration, some of these towns have lost many of their unique characteristics, especially with regard to their dwellings. This research thus attempts to interpret the relationships between the spatial configuration of traditional dwellings in Saudi Arabia and their socio-cultural principles and values, focusing on decoding their interior spatial constants and genotypes. The study pro-poses the use of space syntax theory, represented by the justified plan graph method, as an appropriate socio-spatial methodology for such work, targeting the traditional town of Riyadh Al-Khabra in Qassim province as a case study area, with eight dwellings built between 1900 and 1940 used as examples. Interpretation of analysis results enabled defining spatial constants digitally in these traditional dwellings through the benefit of syntactic analysis tech-niques, and the main findings of this research reveal the significance of various social and cultural factors and customs among inhabitants with regard to determining the spatial form and properties of traditional dwellings in towns such as Riyadh Al-Khabra.


Introduction
Houses or dwellings are associated with the elements of safety and control, as well as offering a reflection of values and ideas, a place for social relationships, a refuge from the outside world, and an indicator of personal status [1]. Traditionally speaking, dwellings can be defined as places distinguished by respect for various human, social and environmental dimensions, thus offering an expression of human traditions, customs, and culture at the time and place of their creation [2]. From a social point of view, a dwelling is an expression of how households accommodate human everyday activities over time, while from an architectural point of view, it is a pattern or a spatial arrangement that elucidates how spaces become connected to each other based on how activities are grouped and separated.
Traditional dwellings were generally influenced by various socio-cultural factors, primarily based on inhabitants' freedom of choice in the presence of other non-negotiable factors such as climate, economy, materials, and technology. This is clarified by Reference [3] assertion that any traditional dwelling is usually a result of evolution over successive generations. Reference [4] further emphasizes the fact that a dwelling is a social artifact, thus playing an essential social role: he describes this as a true reflection of the internal activities, suggesting that the social meaning of any dwelling is reflected through the arrangement and distribution of spaces within it. Space can thus be considered a social product to be developed through social relationships, though it is not simply supported by those relationships, rather generated by them [5].
Focusing on traditional settlements in Saudi Arabia, they are distinguished by having retained various traditional towns and villages, including numerous dwellings that reveal a fascinating mix of authenticity, culture, and tradition and represent important eras in the past. Most of the traditional towns confront an irrecoverable loss of indigenous architectural characters and patterns which has been perpetuated by the local population's abandonment [6] [7], and related failures in conservation and restoration [8].
Qassim province, represented by Riyadh Al-Khabra's town, is one of those sites that encompass distinct traditional settlements. However, the literature review shows that no studies have been conducted on understanding or preserving its indigenous architectural characters and socio-spatial patterns despite many dwellings being in a decent shape and retaining their original traits. Figure 1 illustrates some examples of these dwellings from Riyadh Al-Khabra's town.
However, this research is directed toward answering the following questions that targets the socio-cultural essence of traditional Saudi dwellings' spatial relations in order to foster their values: What is the relationship between the spatial World Journal of Engineering and Technology configuration of traditional dwellings in Riyadh Al-Khabra's town and its socio-cultural principles and values? In addition, how can the interior spatial constants and genotypes be identified?
To answer these research questions, this paper primarily adopts using the space syntax methodology as it enables to describe the spatial properties links between inhabitants' behaviors and various socio-cultural factors with respect to interpreting both the use of spaces and spatial configurations.

The Traditional Saudi Dwelling
Traditional built environments are established based on dwellers' perceptions of their own physical, biological, social, and cultural interactions, which they must consider to form their own settlements [9]. Reference [10] states that traditional architecture and its dwellings in Saudi Arabia represent a strong and distinctive local identity that reflects the region's Islamic values and cultural customs, thus representing a basis for the behavior of inhabitants in the form of a product that meets the needs of human scale, human values, and local society. Moreover, Saudi's residential architecture is further distinguished by its response to multiple non-negotiable factors such as the harsh climate, local culture, economic limitations, and the availability of local building materials [11].
Reference [12] indicates that Saudi's traditional architecture, as represented by these dwellings, contains various symbolic dimensions that can be used to clarify the way architectural elements are transformed into nonverbal signals that express the culture of a society and act as a tool for communication between people.
Thus, it can be said that it has a meaning that goes beyond its physical form, expressing the surrounding community.

Space Syntax Theory and Applications
Space syntax theory was conceived by Hillier, Hanson, and their colleagues at the Bartlett School of Architecture, University College London in the late 1970s to early 1980s [13]. The theory is a science-based approach that focuses on studying spaces as spatial configurations based on understanding their relationships World Journal of Engineering and Technology with a range of social, economic, and environmental phenomena [14]. The significance of this theory lies in the ability to analyze and understand spatial layouts and their relation to human activities patterns in those spaces. Reference [13] thus argues that the theory can be utilized to develop insights into mutually constructive relationships between society and space, based on the ways in which spatial layouts impact social patterns; thus, buildings must be recognized as having social value. The theory also delivers descriptive and qualitative analyses of spatial configurations and urban systems that span the breadth of scale, from the interior of a single room to an entire city [15].
The space syntax theory represents the use of spatial configuration concepts to explain people's behaviors, perceptions, and social activities, where spatial configuration is defined as any and all the relationships that exist between a number of spaces in both simple and complex spatial systems, taking into account all other spaces in the complex [16] [17] [18].
Reference [19] thus simplifies the spatial configuration concept, as shown in the graphic example in Figure 2. This demonstrates a cell divided into two sub-cells, namely a and b, where space a is connected to space b by means of a permeable door, creating a relationship between the two spaces. When a third space (c) is added to the system, the relationships between a and b are changed, however. Case 1(b) shows spaces a and b both being connected directly to space c, and thus continuing to have an equal relationship, while in case 1(c), only space a is connected directly to space c, making it compulsory for users to pass through a to reach space b from space c. These three simple cases thus illustrate how relationships between two spaces can be changed when a third space is added to a spatial system, as well as how two spaces can be connected by means of a third space. A considerable volume of literature has been published based on space syntax theory and its applications as a way to understand the impact of social and cultural factors on space usage and spatial configuration. One of the most notable publications in the early development of the theory was a study by reference [20]. Using space syntax theory, they examined seventeen samples of houses to measure how various functions were adapted to varied spatial configurations.
Reference [21] also adopted the theory to analyze several houses in Ankara, Turkey, as a way to identify houses pattern genotypes and their transformation over time. Additionally, reference [22] investigated the spatial configurations of several dwellings built in different historical periods in Adana, Turkey, applying space syntax tools to explore outcomes determined by space-related adjacencies and how complex spatial configuration systems can affect space functions and usages. Similarly, reference [23] endeavored to decode traditional Berber dwellings in Algeria in the Aures region: their research assumed that despite the impact of key natural variables in the region, such as topographic, climatic, and tribal differences, various spatial constants in these dwellings serve as common at-tributes for Berber spatial and social structures.

The Case Study Selection and Dwellings Samples
The Riyadh Al Khabra governorate, located at the heart of the Al-Qassim province ( Figure 3) is an ancient town, established at the end of the 12th century AH  1) Dwellings being in good conditions that retain many of their original features and can be eligible for conducting the study.
2) The possibility to conduct personal interviews with people who had previously lived in these dwellings (four samples).
3) Dwellings that represent the prevailing pattern in the town which were inferred from the field survey.
Data were collected during a field visit, with the selected dwellings surveyed using electronic instruments. The resulting data then were transformed into a CAD model using AutoCAD software. The key functions of each space in the examined dwellings were calibrated and observed in comparison to interviews conducted with people living in those dwellings. Table 1

Methodology
This research employs the theory of space syntax, represented by the Justified

Plan Graph (JPG) technique to investigate and decode traditional dwellings in
Riyadh Al-Khabra in KSA. This theory was adopted as it enables the creation of links between inhabitants' behaviors and various socio-cultural factors with respect to interpreting both the use of spaces and spatial configurations. In addition, the theory provides the capacity and innovativeness of analyzing spatial relationships and explaining the socio-spatial organization [26]. Regarding historical sites, reference [27] also confirms that space syntax tools can be efficacy utilized in the accurate analysis of relationships between exterior or interior spaces within any heritage-built environment. The Justified Plan Graph (JPG) is a practical analytical technique that offers a graphical, mathematical, and associated theoretical paradigm for analyzing the spatial configuration of buildings [28]. Within this technique, building diagrams are subdivided into multiple components representing spatial configurations, with each configurational node in the JPG referring to a space, and the linking lines between the nodes referring to the interconnections and relationships between those spaces. A JPG performed in conjunction with JASS software thus provides mathematical data and various measurement variables related to the syntactical characteristics of the spatial configuration of the associated buildings [29].
In this research, analysis was carried out on the selected dwellings as a way to explore the similarities and differentiation between the observed spatial patterns in terms of spatial characteristics. The functional spaces in the spatial system were analyzed both with and without exterior calculation. The main parameters used in the analysis were thus as follows: mean depth (MD), real relative asymmetry (RRA), base difference factor (BDF), and space-link ratio (SLR). In addition, the analysis considered syntactical characteristics such as symmetry, asymmetry, distributedness, and non-distributedness as essential measures within the investigation process to determine the necessary features for the justified plan graphs.
The analysis procedures implemented in this research were thus: 1) All traditional dwelling samples were surveyed and then drawn using Au-toCAD software. These drawings were then converted to justified plan graphs (JPG), taking the exterior as the root by dividing the spaces into elements within the creation of the JPG, with the nodes representing the rooms and the lines representing the relationships between those rooms.
2) Spatial configuration is analyzed by calculating different syntactical parameters, such as the mean depth (MD), the real relative asymmetry (RRA), the space-link ratio (SLR), and the base different factor (BDF).
3) Once analyses of these parameters were obtained, the genotypes of the dwellings were determined.
4) The dominant topological types and spaces were then identified in each case. 5) Finally, a comparison was made between the genotypes of dwellings to identify similarities and differences in their spatial configurations.

Visual Review
Visual review analysis is an essential configurational feature for any spatial sys-World Journal of Engineering and Technology tem, as it indicates the number of areas (often referred to as "steps") through which a person must pass to move from one particular area to any other area in the configuration [21].

Mean Depth (MD)
Reference [14], defines the values of mean depth (MD) as it represents how deep or shallow a spatial system within a particular space. Table 2 shows that the mean depth across the eight selected dwellings ranges between 2.43 and 3.20, offering an indication of a lack of accessibility steps for moving to the deepest spaces in the system: the average of all mean depth values is 2.78. This can be generally attributed to the simplicity of forming links between spaces, as shown on the JPG.
The highest average depth, 3.20, is obtained for sample 6, which is as expected, as this sample contains the largest number of spaces (21 spaces) and has the deepest number of levels (6). Across the other seven dwellings, for example in samples 3, 1, and 5, the number of levels is equal (5), but these vary in number World Journal of Engineering and Technology    (Figure 4(c)).
A similar effect occurs in comparing dwelling samples 7 and 4, with the MD in sample 7 being 2.51, which is higher than that for sample 4, representing a deeper and higher number of spaces. This is not the case for the rest of the dwellings, however, which show only slight differences between MD values and the number of spaces identified.

Integration (RRA)
To eliminate potential unwarranted effects due to the number of spaces in a system, and thus to compare systems of different sizes, a derived scale known as "integration value" can be used [21]. The integration value (RRA) of space represents the relative depth of the space as compared to all other elements in the JPG [20]. A comparison of the integration values of all houses is shown in Table 2.
These values are calculated twice for each house, the first time considering the carrier (exterior) and the next without the carrier. This allows for additional insight into the role of the exterior in the resulting segregation or integration of the dwellings' spatial configuration. As shown in Table 2, there is a slight increase in the integration values for all samples when the carrier (the exterior) is World Journal of Engineering and Technology excluded, which suggests that there is no apparent impact of the exterior on the integration of these systems.

Base Different Factor (BDF)
The base different factor (BDF) measures degree of variation in integration values, and thus indicates the strength of a spatial organization of any spatial system. When the BDF value tends to 0, this indicates strong differentiation and greater structure, while when the value tends to 1, weaker differences between spaces must be assumed [20]. As shown in Table 2, the lowest value of BDF with or without inclusion of the exterior (carrier) is 0.94 and the highest value is 1.01.
However, the average BDF is 0.98 for both scenarios. The BDF values thus indicate a weak functional differentiation of all samples, based on them approaching a value of 1, which further denotes weak differences between spaces.

Space Link Ratio (SLR)
Dwellings can also be examined in terms of the rings embedded in their spatial structures. For example, as shown in the justified plan graphs (Figure 4 and

Topological Types
There are several types of spaces available that may act to fulfill occupancy and movement needs. Considering the essential topological characteristics represented in the justified plan graphs [19]. The spatial configurations are categorized by four topological spaces: the a-type space, with one link; the b-type space, with more than one link in a tree formation; the c-type space, with more than one link in a ring formation; and the d-type space, with more than one link that is also linked to two or more rings [30]. Table 3, the dominance of c-type spaces is seen in five samples (1, 4, 5, 6, and 7), followed by a-type and then d-type spaces. In three samples (2, 3, and 8), a-type is dominant, followed by c-type: however, the third dominant typology in samples 3 and 8 is d-type, while in sample 2, it is b-type. The dominance of a-type typology in samples 2, 3, and 8 is due to the use of AMP space, which in samples 2 and 8 is limited to family use and has no access from the guest section, while in sample 3, it is non-existent. In the other samples, the (AMP) has access to the hospitality section, thus allowing it to be both an occupancy and a movement space, causing the dominant topological type to be the c-type. As long as the c-type is the most dominant which is formed in rings in World Journal of Engineering and Technology Reference [20], states the rings are formed when spaces are linked together in circuits that allow passing to space through more than one path. The rings in any spatial system can also reveal several essential inherent features in the spatial patterns of such buildings as in dwellings. The number of spaces that sits on a single ring path represents the relationships between spaces. This allows dwellings to be compared based on their connectivity forms.

As shown in
As shown in Table 4 There may appear to be a difference in spaces, but some are integrated between two spaces of the ring path 1. This is constant in all samples, regardless of the space steps. Furthermore, this path is intended to be only used by the dwelling's owner or male relatives, without letting females pass through it.
Ring path 2 as shown in Table 4 is constituted as a third entrance in some  (Figure 4(c)).

VES.F
The presence of this path could be attributed to the fact that the work area should be located close to the dwelling's owner zone. However, from the interviews, it seems that the most probable reason for establishing this path is the social customs that consider the importance of hospitality since the guest room is placed adjacent to the carpentry shop (O.RO), so clients could be directly invited to the house.
As for the internal rings' paths, Table 5 shows that internal ring path 1 is recurring by 100%. From the justified plan graphs and architectural drawings of the samples, the presence of the Firewood store (FS) seems to be the reason for the recurrence of this ring path in all samples.
This recurring ring always appears as a link between the males' guest section and the family section. This link is used to supply (GR.M) with the (FS) through the family section. The storage's entrance is too narrow for a person to pass through. Therefore, this can be attributed to the fact that ladies are not permitted to access the male guest section, so the existence of this path is for only services purpose. For instance, if females are permitted to enter the male guest section, then such a path becomes unnecessary since the storage room can be served whenever the male guest section is not in use. This reinforces the principle of privacy and strict customs in restricting physical presence in this space to males only.
The internal ring path 2 in samples 1, 4, 5 and 7, as shown in Table 5, and the justified plan graphs, affirms that the access to a multi-purpose room (AMP) is the reason for establishing this path. Based on interviews, the (AMP) has different roles depending on its location. It can occasionally be used for guests to sleep, so it is linked to the (GR.M). However, it can also be used for other purposes. What we are concerned about here is the (AMP) link with the family  which are relatively long hops. This applies to sample 6; though there is no (AMP) space in the ring, the justified plan graph shows that this path will reach roof (RF), which ends with (AMP).
However, the above analysis demonstrates the idea of social cognition prevailing through design since it is determined that path 1 is constrained by not permitting, whereas path 2 allows accessing non-physically (through listening) without breaching societal customs.
Although there is no ring path in samples 2 and 8, they can be found in their spaces (APM), which are functionally related to the family section but not accessible from the visitors' section. This demonstrates that the primary purpose of (AMP) space is to provide acoustic access to the family section rather than males.
Some paths, such as the one in sample 3, can be considered exceptional cases, such as the ring path that connects the bedroom room (RO1) to the family hall (F.H) and to (YR.F). This path may have been created to meet a specific requirement, as the resident of this dwelling stated during the interview that this path did not exist in the first place but was constructed after some time of living.
When the topological types are identified, it is also possible to use two addi-World Journal of Engineering and Technology tional measures, however, represented by scales of distributedness/non-distributedness and symmetry/asymmetry, which can further express the spatial qualities of the system. Distribution and non-distribution are values that may be used for understanding the spatial characteristics of depth and permeability in a spatial structure [31]. Reference [14], explains that in the case of a non-distributed spatial structure, there is only one path from a given space to another, while in the case of distributed spatial structure, various paths are constituted in rings. However, A low value thus indicates a distributed structure, while a high value indicates a non-distributed structure [32].
Reference [32], the symmetry/asymmetry scale reveals how spaces are used to classify activities or social roles, thus offering a way to understand the relationship between a space's occupants and its design in terms of merging or separation. Low values indicate asymmetric areas, while high values are more symmetrical.
From Table 3, it is clear that the distribution values in dwelling samples 1, 3, 4, 5, 6, 7, and 8 range between 0.40 and 1.00: these low values indicate that these samples are characterized by high distribution levels. Sample 2 shows more distributional moderation, with a value of 2.20. With regard to symmetry values, the four dwelling samples whose values range between 0.75 and 1.00 are characterized by asymmetric spatial structures, while the four samples whose values range between 1.11 and 1.57 are relatively symmetrical. In general, all dwelling samples examined in the town are characterized by high distribution and some asymmetry. This indicates that the movement within the spatial systems is highly flexible, and that the spatial structure is integrated.

Dwellings Genotypes
The genotype can be defined as the spatial arrangement of any socio-spatial structure [14]. The number of spaces and the ordination of relative symmetry values thus illustrate spatial relationships and reveal the inherited typology entrenched in a given spatial system. The existence of socio-cultural genotypes can therefore be identified when the rank order of integration values in the spatial system is consistent [14]. Table 6 shows the real relative asymmetry values (RRA) of all dwelling samples, ranging from the lowest to the highest. This thus identifies the most integrated spaces and the most separated spaces in these spatial systems.
In samples 1 and 5, the rank order reveals the Yard-Family and Arcade-Family (YR.F-AR.F) areas as the most integrated spaces. In samples 2 and 4, however, the rank order shows only the Arcade-Family areas (AR.F) as integrated spaces, while in sample 3, the family hall (F.H) is the main integrated space. Although these spaces have different names, their functions are similar, with the rest of the family section spaces in their particular systems being distributed around them. A similar pattern applies to samples 6, 7, and 8, where the rank order shows the yard-family (YR.F) as the most integrated space, followed by the Arcade-Family

Conclusions
Using space syntax theory, represented by the justified plan graph method, this research attempted to analyze and interpret the socio-cultural characteristics inherent in the spatial configurations of traditional dwellings. The research focused on Riyadh Al Khabra's town, located in Qassim province, Saudi Arabia, as a case study area, as the population of this town is shrinking.
From the analysis and findings, several features of traditional dwellings in the town can be summarized:  Simplicity in the spatial configuration is common, with spaces reached through a few accessibility steps, and movement and transition within the entire spatial structure being flexible. Dwellings have low average depth levels, and the semi-deep system predominates on the justified plan graphs, characterized by a multiple ring system across all dwellings.  Strict constraints are inherent in the separation between the family section and any hospitality or guest section, which begins at the exterior, with each dwelling containing two entrances. Nevertheless, the spatial configuration of some spaces seems to be relatively flexible, as seen in the cases of multi-purpose rooms (AMP), with non-physical access between the two sections (through listening and speaking) thus allowed without breaching societal customs.  Oriented movement system "permeability" in all dwellings' spatial configuration, where all have at least two entrances (family and guests) and numerous space steps inside rings.  All dwellings bear a consistent genotype pattern formed by the presence of two clear spaces, in which the family section as a whole is the primary area and starting point, representing the most integrated area, while the multipurpose room (AMP) represents the most isolated space.  Although these dwellings were not built by architects and no formal requirements or standards were applied at that time, there is a unique and remarkable common system rooted in their interior spatial configurations, despite differences in their built forms.  It can thus be concluded that the influence of inhabitants' social customs on the architecture of the town's traditional dwellings is the prominent and most influential feature of these spatial configurations.
Overall, the outcomes of this research emphasize the significance of social and cultural factors and inhabitants' customs in determining the spatial layout of buildings. It also elucidates how useful space syntax can be as a social tool for determining the spatial and configurational properties of a dwelling's structure.
Further research by expanding the dwellings samples, exploring other traditional towns, or even comparing with the new modern dwellings could result in new