Journal of Sustainable Architecture and Civil Engineering 2022/1/30 50 *Corresponding author: Bemanian@modares.ac.ir Role of the Architectural Application of Nature in Improving the Quality of Semantic Depth in Iranian Urban HousingReceived 2021/12/09 Accepted after revision 2022/02/10 Journal of Sustainable Architecture and Civil Engineering Vol. 1 / No. 30 / 2022 pp. 50-64 DOI 10.5755/j01.sace.30.1.30226 Role of the Architectural Application of Nature in Improving the Quality of Semantic Depth in Iranian Urban Housing JSACE 1/30 http://dx.doi.org/10.5755/j01.sace.30.1.30226 Mohammadhossein Azizibabani Ph.D. Student in Architecture, Department of Architecture, Faculty of Arts, Tarbiat Modares University, Tehran, Iran. Mohammadreza Bemanian Professor at the Department of Architecture, Faculty of Arts, Tarbiat Modares University, Tehran, Iran. Introduction Abstract The purpose of this study is to investigate the effects of the architectural application of nature’s (AAN) components in improving the quality of semantic depth in Iranian urban housing to determine the most effective architectural indicators in this context. This research uses a mixed methodology in terms of the data’s nature, and the research method is descriptive-analytical (causal and comparative). The components and indicators related to the AAN have been collected through the study of theoretical foundations and literature review. To determine the relationship between these components and the semantic depth variable in housing design, the method of logical reasoning has been employed. Data were collected through a questionnaire with the participation of 96 occupants of Phase 1 of Ekbatan residential town, to determine the perceived quality of research variables. The results of regression analysis on quantitative data confirm the research hypothesis regarding the key role of maintaining the principle of spatial hierarchy in increasing the possibility of understanding the semantic layers in housing that most of them exist due to the presence of various manifestations of nature. Keywords: architectural application of nature, semantic depth, spatial hierarchy, qualitative aspects of nature, Iranian urban housing. Nature has always been the context of human activities, and the construction of any kind of build- ings that aims to meet human needs and expectations always requires touching nature and con- templating the threefold relationship between man, nature, and architecture. This relationship de- pends on the position of nature and its related components in the worldview, culture, and lifestyle of society. There is also an obvious interaction between the architecture form and content with nature. Concerning the development of human settlements, the two approaches of overcoming nature or interacting with it are more theoretically discussed. The first approach whose intellectual roots date back to the late renaissance considers nature as a mechanism whose order is mechan- ical (Nasr, 1996). According to this view, architecture operates using a human-centered approach 51 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 to overcoming nature, regardless of the limitations and potentials of the context and relying on technology capabilities. The basis of the second approach is taking advantage of the potentials of nature to provide the proper conditions for human comfort (Noghrekar, 2013). In this regard, Iranian architects have succeeded in creating an environment conducive to human habitation in harsh climates by making proper use of the capabilities of the earth and elements such as water, wind, plants, knowledge of the principles of shading, and understanding the properties of natural elements and materials. The difference between a house and a shelter is providing the necessities to meet the psycholog- ical and spiritual needs of man along with his material needs. Therefore, housing is not a purely functional subject and the presence of semantic layers in its spaces is effective in meeting human high-levels needs. Nature has always been respected from the perspective of the monotheistic worldview and Islamic culture that prevails in Iranian society, and it is a sacred thing that has been considered as a sign of the presence of God. Therefore, from the perspective of Iranian-Islamic culture, the application of natural elements or their dominated rules and qualities in architectural design can be an important factor in inducing implicit and explicit concepts and values through creating semantic layers in housing design and this process ultimately leads to improved quality of semantic depth in housing design. In this regard, nature appears in the architecture of traditional Iranian houses, sometimes as objective forms and sometimes as qualities derived from the con- ceptual, functional, and formal features of natural elements. But in new types of urban housing, especially apartment complexes, there are many restrictions on direct contact with nature in the interior of the residential units. This shows the importance of landscape design in open spaces of these complexes and the application of subjective qualities derived from nature and its objective aspects. In other words, it can be acknowledged that the architectural application of nature (AAN) creates the main semantic layers of the house, which in their absence, a house has no different from a shelter. Therefore, this study was conducted to investigate the effects of the AAN’s com- ponents on improving the quality of semantic depth in Iranian urban housing to present practical strategies in new types of urban housing. In this regard, the following questions are raised: What components of AAN affect the quality of semantic depth in Iranian urban housing? What is the mechanism of the effects of these components in improving the quality of semantic depth? Theoretical Foundations and Literature Review Nature is the source of responding to human physical and spiritual needs and inspires him in his creations and initiatives. The relationship between architecture and nature, generally, can be in- vestigated in three periods: pre-modern, modern, and postmodern. The general concept of nature in the pre-modern era was known as the origin and essence of things. In this context, the cosmic character of nature has taken precedence over its terrestrial character (Falahat & Shahidi, 2010). After the Industrial Revolution and the advancement of technology and the prevalence of humanist thought, especially in Western societies, the concept of nature was considered equivalent to the whole material world, which includes all beings and resources needed for industrial development. In this view, nature has been dominated by man to meet his material needs and Functionalism has been the dominant aspect of architecture. The purpose of architecture was limited to meeting the material and in some cases the psychological human needs. In the postmodern era, ecosystems and the type of relationship between living things and the environment were considered by archi- tects, the result of which was the emergence of concepts such as sustainability, climatic architec- ture, eco-architecture, biophilic design, and so on. During this period, technology sided with nature to resolve the crisis of modernist thoughts. Among these concepts, the biophilic design which is based on the biophilia theory was developed and adapted within the architectural domain, at the beginning of the 21st century (Zhong, Schroder, & Bekkering, In press). Based on the biophilia hypothesis by wilson (1984;1993) Biophilia is ‘the innately emotional affiliation of human beings Journal of Sustainable Architecture and Civil Engineering 2022/1/30 52 to other living organisms.’ After humans migrated to the built environment, we inherited a need for nature, which evolved into ‘thinking about nature’. Kellert (1993;2008) defines biophilia values as ‘utilitarian, naturalistic, scientific, aesthetic, symbolic, humanistic, moralistic, dominionistic, and negativistic’. He also defines biophilic design as ‘a deliberate attempt to satisfy the need of contact with natural systems and processes in the contemporary built environment, and to improve peo- ple’s physical and mental health, productivity and wellbeing’. The development of any kind of human settlement requires concentrating on the threefold relation- ship between man, nature, and architecture. Gruter (1987) categorizes three practical approaches to these relationships. In his view, in the schools of thought of nature opposition, man and nature have no relation with the supernatural world, and the goal of man during his presence in this world is only the material exploitation of nature to meet the needs of his material dimension. The objective manifestation of such an approach in architecture is mainly related to the architectural developments after the Industrial Revolution and the period of modern architecture. Nature dispar- ity schools of thought have sought to humanize nature. From the viewpoint of these schools, man and nature have two completely different essences. Therefore, the main strategy in architecture has been to separate man from nature. In naturalistic schools of thought, the main approach is to naturalize man. From the viewpoint of these schools, any transcendental realm is within this nature, and the only way to reach it is to conform to nature. The view of naturalism has existed in Eastern schools for a long time, but a kind of formal naturalism can also be sought in the form of organic architecture in the West. The main difference between Eastern and Western schools of thought in this area is the general view of God. In the Eastern schools, nature is a sacred thing and their status has risen to the level of divinity and in some cases, they turn to the worship of nature. But in Western naturalistic schools of thought, the dignity of divinity is diminished and the gods are equivalent to nature. Noghrekar (2013) confirms this classification and introduces nature making schools of thought on the relationship between man, nature, and architecture. In these schools of thought, which are in line with the Iranian-Islamic culture, nature is a part of man and acquires its identity from him, but both have a divine essence. Numerous studies have examined the role of nature and its related elements in Iranian architec- ture. Afshari Basir et al (2017) have investigated the presence of water, plant, and light elements in traditional houses in Yazd and concluded that these buildings are designed concerning nature. Adeli (2013), outlines two fundamental principles of human and nature’s intrinsic unity and human per- fectionism about the human-nature relationship within the framework of Islamic ontology. Dane- shjoo et al (2015) have concluded that the use of natural-based materials and natural forms has had the greatest impact on how to tend to nature in contemporary Iranian architecture. Keramati (2007) believes that nowadays the component of nature in architecture is so poor so that the triple relation of man, nature, and architecture is unrecognizable. Daeipour (2014) believes that nature’s presence plays a positive role in gaining a sense of place in traditional Iranian houses which is due to the ability to activate human sensory, activity, and se- mantic perceptions. Mehdi Nejad et al. (2012) believe that it is not planned for the beauty of nature and the reason for this beauty is the correct response to the performance that converts natural beauty into an intrinsic and unconscious feature and they propose to pay attention to the geometry in the natural elements to enjoy this kind of beauty. Khakzand and Ahmadi (2007) believe that the presence of nature’s spirit in architecture leads to its promotion. Mamani et al. (2018), believe that the principles of Iranian architecture are derived from a rational logic and these principles are found in nature as a divine creation so any artifact that is compatible with these principles is committed to nature and God and respects human beings and human reason. The position of nature from the perspective of Iranian Islamic culture and the review of literature is evidence that the presence of various manifestations of nature is an important factor in improving the quality of semantic depth in housing design. But architectural subtleties play an important role 53 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 in inducing these meanings, therefore, investigation of the presence of nature in the architecture of traditional Iranian houses can be effective in finding the components of the AAN and related indica- tors to improve the quality of semantic depth in new species of urban housing. Semantic Components of the Architectural Application of Nature The presence of nature in Iranian architecture, especially in the residential environment, has always been either in the form of objective elements or qualities, laws, or institutional mechanisms of nature. These items, which in this research were called “architectural application of nature’s com- ponents”, can be classified based on their representative indicators in architecture in the form of three formal, conceptual, and functional factors. The first component that its indicators mainly appear in the architectural forms is unity. The unity of nature idea is a strong metatheoretical theme in several scientific and environmental fields and the reason of adaptation this idea to these fields is to give rise to an inspiring, optimistic, socially-re- sponsive, and environmentally-friendly worldview (Marshall, 1999). Leibniz believes that monads, as inseparable components in nature, have unity. According to this view, the universe is an orga- nized system in which Infinite types of monads have been combined to create a harmonious whole (Copleston, 1993). Therefore, the quality of unity is present in almost all natural systems and ele- ments, also based on the position of nature in Iranian Islamic culture, its use in architecture refers to the oneness of God. Transparency is another semantic component related to the AAN which its architectural indica- tors are reflected in the form, space structure, and details. Transparency and the absence of clear boundaries are obvious features in most natural landscapes. Also, the presence of water and light in the traditional houses of Iran is one of the primary priorities, which is a manifestation of trans- parency and purity. There are basically two ways of transparency in architecture; Literal transpar- ency indicates how clear the visual boundary between the interior and the exterior space is, and phenomenal transparency which defines a type of architectural organization and is seen spatially in the form of ambiguity and uncertainty in spatial boundaries. The most prominent feature of this organization is that it is possible to have a simultaneous perception of different spatial locations, just as the metaphorical meaning of the term (easy to perceive or detect) indicates (Rowe & Slutz- ky, 1963). Honesty is considered one of the greatest moral virtues and an attribute of the essence of God. Since nature is one of the manifestations of God in Iranian culture, therefore, it is free from all lies. The indicators of this quality in architecture are mainly related to the materials, static, and the functionality of the building’s elements. A true architecture can be defined when the intention and spaces truly serve the function they simply should. The main point is to allow the building to speak of its nature and intention through the materials used, spaces designed or the structure built (Harries, 1984). Hierarchy is one of the principles governing natural collections, components, and phenomena. The existence of beings is a function of a defined hierarchy whose undeniable role in defining the com- ponents of a collection and identifying them is important. Hierarchical order defines the position and value of each component of a whole as well as the value of a whole individually and relative to other collections (Naghizadeh, 2012). Types of hierarchies in the man-made environment can be divided into two categories: legal and real hierarchies. The dimensions of the hierarchy can also be divided into neighborhood, functional, transit, and spatial hierarchy, which the last one is so import- ant in Iranian traditional houses and is related to the principles of privacy and introversion. In addition to these four components, due to the position of nature in Iranian Islamic culture, the presence of objective forms of nature can also enhance the semantic depth in housing design. Nature’s objective presence has always been observed in Iranian architecture in three appearances of primary, secondary, and abstract. Primary nature’s appearance refers to the concept of nature Journal of Sustainable Architecture and Civil Engineering 2022/1/30 54 that has not been transformed by man (Spirn, 2000, p. 41). In this regard, the possibility of visual relation with the sky, benefiting from sunshine, wind, planting, and the presence of water in the central courtyard can be mentioned as indicators of the primary appearance of nature in Iranian architecture. The abstract appearance of nature is mainly manifested in the form of patterns and abstract forms of natural elements in the decorations or form of the building components. Although the relation- ship with the primary and abstract appearance of nature in architecture is effective in providing suit- able climatic conditions and increasing the quality of sensory beauty. but due to the cultural context and the symbolic role of natural elements, the application of these components can also enhance the semantic depth in architecture. AAN’s components are not the only factors that promote semantic depth in residential environ- ments, and this is highly dependent on the mental background of the target community, which originates from cultural and social contexts. But in this study, considering the position of nature in Iranian culture and the symbolic role of natural elements, the objective forms of the presence of nature in architecture including primary and abstract appearance along with qualities such as unity, transparency, honesty, and hierarchy were considered as the semantic components of the AAN. Each of these components, depending on how they are used, can be effective in improving the qual- ity of semantic depth in architecture from the perspective of the worldview and cultural context of the target community. Indicators related to these components which have been collected through literature review are presented in Table 1. Table 1 Indicators related to the semantic components of the AAN C o m po ne nt s Indicators Descriptions and Figures Source U ni ty Modular design Fig. 1. Modular system in an Iranian traditional house (Pirnia M. , 1992) Holistic approach (Har- mony with urban fabric in terms of orientation, building materials, Full and empty spaces, and so on ) Fig. 2. Historical Context of Yazd (Vincent, 2014) Using logical, numerical and geometric propor- tions Fig. 3. Application of the enclosed rectangle in a regular hexagon in the proportions of traditional Iranian houses (Hejazi, 2009) Similar proportions in decorations and geomet- ric structure Fig. 4. The yard enclosure is a constructor of dividing lines- Tabatabai’s house in Kashan (Ansari & Ebrahimi, 2010) 55 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 C o m po ne nt s Indicators Descriptions and Figures Source Tr an sp ar en cy Mass reduction due to the dominance of space over mass (Embedding the central courtyard and so on) Fig. 5. The transparency created by the installation of the central courtyard and the permeability of the walls- Golshan House in Yazd (Noghrekar, 2008) (Maza- heri, Dezhdar, & Mousavi, 2018) (Momeni, 2018) Visual continuity due to the sequence of spaces and the permeability of the walls Use of reflection phe- nomena and translucent openings Fig. 6. Tabatabai’s house in Kashan H on es ty Compatibility of the fa- cade and its backspaces Fig. 7. Method of transfer of forces in the structure of an Iranian traditional house Authors Using functional compo- nents in the building (Pirnia, 1997) Demonstrating the trans- fer of forces in the struc- ture of building properly and the use of self-static forms and materials (Bemanian & Amini, 2011) Using primary color and texture of natural materials Authors H ie ra rc hy Functional and visual separation of different areas outside and inside the house Fig. 8. Real hierarchy (A) and Customary Hierarchy (B) (Shia, 2007) (Tabibian, Charbgoo, & Abdolahimehr, 2012) Customary separation of areas on the way to the house Avoiding indoor visibility from outside Fig. 9. Avoiding indoor visibility from outside in an Iranian traditional house Journal of Sustainable Architecture and Civil Engineering 2022/1/30 56 Research methodology The investigation of theoretical foundations and review of the literature shows that the presence of objective examples of nature besides the adaptation of nature’s qualities and laws in architecture has been the main factor in promoting semantic depth in the traditional Iranian houses. The presence of the primary and abstract appearance of nature, in addition to the functions related to the regula- tion of environmental conditions and aesthetics, also have a semantic burden due to the symbolic role of the natural elements. The qualities of honesty, transparency, unity, and hierarchy, regardless of their effects on functionalism, formal aesthetics, and maintaining privacy in the Iranian houses, also include spiritual concepts. The important point is to create the necessary context to understand these semantic layers. Therefore, it is hypothesized that observing the principle of spatial hierar- chy, considering its effects on increasing the privacy of housing, provides the necessary basis for mental preparation and the possibility of personal privacy and thinking about the semantic layers of housing which large amounts of them are created by improving the quality of applying the primary appearance of nature. Therefore, it is hypothesized that the application of the principle of the spatial hierarchy will have the greatest role in improving the quality of semantic depth in housing. This research uses a mixed methodology in terms of the data’s nature, and the research method is descriptive-analytical (causal and comparative). Semantic components of the AAN and their related indicators were collected through reviewing the literature using the qualitative content analysis meth- od. The perceived qualities of these components are considered as independent variables of research which the perceived quality of semantic depth in housing is a dependent variable on them. To investi- gate the relationship between these variables a survey was conducted in Phase 1 of Ekbatan residential town in Tehran. In this regard, The results of the authors’ observations on recognizing the indicators related to the research variables were provided to the residents in the form of photos or architectural drawings along with a questionnaire.The questionnaire consists of 29 questions. Six of which relate to the socio-demographic variables including age, sex, education, marital status, residence history, and ownership status. Nineteen questions relate to determining the perceived qualities of the indicators of dependent variables (the components of AAN), and four questions relate to determining the perceived C o m po ne nt s Indicators Descriptions and Figures Source P ri m ar y ap pe ar an ce communicating with the sky, surrounding landscapes and natural elements Fig. 10. Appropriate proportions for visual communication with the sky- Placing Pool, trees and wind catcher in the central courtyard AuthorsPlacing pool, waterfront, trees, and plants in the open spaces Providing airflow and sun- light in the living space A bs tr ac ti on a pp ea ra nc e Using abstract forms of natural elements in the motifs and decorations Fig. 11. Abstract patterns of nature in borojerdiha’s House in Kashan (Makinejad, 2008) 57 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 quality of semantic depth in housing. The scale of the questionnaire is based on the 5-point Likert scale that to present the regression equation related to the effects of independent variables on semantic depth, the data have been fuzzy based on the following table and formula. To aggregate the occupants’ views, the average of the fuzzy numbers is obtained from the following equation. Fuzzy number =(l, m, u) F.AVE= ( ∑𝑙𝑙𝑙𝑙 𝑛𝑛𝑛𝑛 + ∑𝑚𝑚𝑚𝑚 𝑛𝑛𝑛𝑛 + ∑𝑢𝑢𝑢𝑢 𝑛𝑛𝑛𝑛 ) = (L, M, U) Number of Fuzzy numbers =n 𝑥𝑥𝑥𝑥 = 𝐿𝐿𝐿𝐿 + 𝑀𝑀𝑀𝑀 + 𝑈𝑈𝑈𝑈 3 (l, m, u) = Fuzzy number n = Number of Fuzzy numbers After calculating the average of fuzzy numbers, the following equation is used to de-fuzzy. Fuzzy number =(l, m, u) F.AVE= ( ∑𝑙𝑙𝑙𝑙 𝑛𝑛𝑛𝑛 + ∑𝑚𝑚𝑚𝑚 𝑛𝑛𝑛𝑛 + ∑𝑢𝑢𝑢𝑢 𝑛𝑛𝑛𝑛 ) = (L, M, U) Number of Fuzzy numbers =n 𝑥𝑥𝑥𝑥 = 𝐿𝐿𝐿𝐿 + 𝑀𝑀𝑀𝑀 + 𝑈𝑈𝑈𝑈 3 The process of collecting data was in the spring of 2021 and the statistical sample includes 96 oc- cupants of phase 1 of Ekbatan residential town. To determine the importance of the effectiveness of each of the semantic components of AAN in improving the quality of semantic depth, regression analysis was performed on the obtained results of the questionnaire. Field study Fig. 12 Location of the Ekbatan residential town. Source: (Yasemi, 2016) A field study has been conducted in the southern part of phase one of Ekbatan residential town located in the west of Tehran (District 5). The initial design of this town is related to the period when the functionalism of modern architecture dominated the housing construction projects in Iran, but landscape design, relationship with natural elements in the open spaces, and the presence of indi- cators related to this research’s variables in the design of this complex have been the reasons of its selection for the basis of the field study. The initial purpose of building Ekbatan was to settle the surplus population of Tehran. The con- struction of Ekbatan was started in 1975 and at this time in 2021, this town consists of three phases including 33 blocks and 15675 residential units. The results of recognizing the indicators related to the research variables in the southern part of the first phase of Ekbatan residential town are shown in Table 3. Table 2 The equivalent of triangular fuzzy numbers to the 5-point Likert spectrum. Source: (Habibi, Izadyar, & Sarafrazi, 2014) (0,0,0/25)(0,0/25,0/50)(0/25,0/50,0/75)(0/50,0/75,1/00)(0/75,1/00,1/00) Very LowLowModerateHighVery High Journal of Sustainable Architecture and Civil Engineering 2022/1/30 58 Table 3 Recognizing the Semantic components of the AAN in the Ekbatan residential town. Source: Authors Co m po ne nt s Indicators Descriptions Figures U ni ty Using module Due to the nature of mass housing, the dimensions of volumetric composition com- ponents have been designat- ed modularly. Fig. 13. Volumetric unity in Ekbatan residential town. Source: (Yasemi, 2016) Holistic approach (Har- mony with urban fabric in terms of orientation, building materials, Full and empty spaces, and so on ) According to the modular design of the blocks, similar details in architectural forms, and using single material in the facades, the project is being seen as a coherent complex. Using logical, numer- ical and geometric proportions The components of the volumetric composition have geometrically fixed propor- tions. Fig. 14. Fixed proportions in volumetric composition components. Source: Authors Similar proportions in decorations and geo- metric structure No items were observed. Tr an sp ar en cy Mass reduction due to the dominance of space over mass (Embedding the central courtyard and so on) The design of the volumetric module has been based on reducing the mass and in- creasing the negative spaces. Fig. 15. Reducing mass and increasing negative spaces in volumetric composition. Source: Authors Visual continuity due to the sequence of spaces and the permeability of the walls The combination of positive and negative spaces and the diverse geometry of the plan reduce the rigidity of the form to some extent, how- ever, the form is not visually permeable. Use of reflection phe- nomena and translu- cent openings The horizontal stretched win- dows create less transparen- cy compared with full-length windows. Regarding the use of the reflection phenome- non due to the installation of ponds and fountains, etc., no significant case was observed. 59 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 Co m po ne nt s Indicators Descriptions Figures H on es ty Compatibility of the facade and its back- spaces The design of the facades does not represent the resi- dential space and has mainly had a formal approach. Fig. 16. View from different sides of the blocks. Source: Authors Using functional com- ponents in the building The design of the volumetric composition and its related elements and details is quite functional. Demonstrating the transfer of forces in the structure of building properly and the use of self-static forms and materials The forms are cubic and visually stable. Using primary color and texture of natural materials The facade of the project is made from concrete with the primary color of cement. H ie ra rc hy Functional and visual separation of different areas outside and inside the house At the scale of phase 1, the hierarchy of public, semi-pub- lic, semi-private (block lobby and floor lobby), and private (residential unit) spaces were observed. Also, the separation of public, private, and service spaces at the level of residen- tial units is evident. Fig. 17. Separation of public and semi-public spaces at the town level. Source: Authors Customary separation of areas on the way to the house The negative spaces in the volumetric composition act as a semi-public space in the pedestrian access hierarchy of blocks. Avoiding indoor visibili- ty from outside The entrance of most resi- dential units has a functional and visual filter space. Fig. 18. Separation of different areas at the level of residential units. Source: Authors Journal of Sustainable Architecture and Civil Engineering 2022/1/30 60 Co m po ne nt s Indicators Descriptions Figures P ri m ar y ap pe ar an ce Communicates with the sky, surrounding landscapes and natural elements On the upper floors, the northern units have a good view of the mountains of Tehran. The central green space in each neighborhood unit has also provided the possibility of proper visual communication with the pri- mary appearance of nature, from inside the residential unit. Fig. 19. Communication with the primary appearance of nature from inside the units and in the open spaces of the complex. Source: Authors Placing pool, water- front, trees, and plants in the open spaces The form of the blocks is designed in such a way as to create open spaces that can act as semi-public shared spaces. The greenery of these spaces has increased over time. Fig. 20. Greenery of negative spaces in volumetric composition. Source: Authors Providing airflow and sunlight in the living space The blocks are stretched from west to east. The volu- metric composition is such that the shading of the blocks on each other is reduced and most residential units can benefit from the desired airflow. Fig. 21. Formation of volumetric composition with the approach of maximum use of airflow and sunlight. Source: Authors A bs tr ac tio n a pp ea ra nc e Using abstract forms of natural elements in the motifs and decorations No case was observed in the architecture of the whole project. This indicator is mostly seen in connection with the decorations and interior furni- ture of the units, which did not exist in the original design. Fig. 22. Association of natural patterns in the geometry of the plan. Source: Authors Using abstract forms of natural elements in the forms of building components The plan of the blocks in phase one is reminiscent of the repetition of hexagonal patterns in nature. 61 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 Results Fig. 23 Percentage of perceived quality of variables. Source: Authors The results of recognition of the variables' indicators and other technical documents of the Ekbatan town were added to the questionnaire. In addition to the request for determining the perceived quali- ty of the mentioned indicators, a request for determining the quality of semantic depth has also been submitted separately. Based on the study of theoretical foundations and review of literature, it was found that architectural applica- tion of the four components of unity, transparency, honesty, and hierarchy, along with the presence of primary and abstract appearance of nature improves the quality of semantic depth in housing design. In statisti- cal analysis, the quality of semantic depth is considered as a dependent variable on the 6 mentioned variables (semantic components of the AAN). The descriptive results related to the percentage of perceived quality of independent and dependent variables are presented in Figure 23. The results of the correlation test between the semantic depth variable and the semantic com- ponents of the AAN show significant relationships. There was also no collinearity between the independent variables. These correlation coefficients confirm the establishment of the first condition for regression anal- ysis. Regression analysis coefficients are presented in Table 5. These coefficients indicate that the components of the hierarchy and transparency have the greatest role in predicting changes of the semantic depth variable. Table 4 Pearson correlation coefficients between independent variables and semantic depth. Source: Authors Honesty Primary appearance Hierarchy Abstraction appearance Transparency Unity Semantic Depth Pearson Correlation .378** .387** .538** .359** . 407** .388** Sig. (2-tailed) .000 .000 .000 .000 .000 .000 N 96 96 96 96 96 96 Table 5 Regression analysis coefficients. Source: Authors Model Unstandardized Coefficients Standardized Coefficients t Sig. Collinearity Statistics B Std. Error Beta Tolerance VIF (Constant) -0.168 .059 -2.840 .006 Honesty 0.162 .074 .157 2.182 .032 .895 1.117 Primary appearance 0.210 .080 .187 2.621 .010 .908 1.101 Hierarchy 0.403 .072 .402 5.615 .000 .901 1.110 Abstraction appearance 0.124 .060 .147 2.058 .043 .906 1.104 Transparency 0.313 .077 .287 4.065 .000 .925 1.081 Unity 0.148 .057 .186 2.610 .011 .912 1.097 a. Dependent Variable: Semantic Depth Primary appearance Honesty Hierarchy Abstraction appearance Transparency Unity Semantic Depth Journal of Sustainable Architecture and Civil Engineering 2022/1/30 62 Discussion and Conclusion One of the main factors in making a difference in the concept of the house with shelter is the quality of semantic depth in housing design. Housing is not a purely functional subject, and in a meaningless home, it is not possible to respond to the higher residential needs of human beings, so the presence of semantic layers in residential environments is necessary to provide a platform for growth and excellence of human personality. Understanding the semantic layers of residential environments is deeply dependent on the cultural context of the target community and the individ- ual’s mental readiness to face the signs and symptoms that convey concepts. Due to the position of nature in the Iranian-Islamic culture, qualitative improvement of components of the AAN is one of the main factors of improving the quality of semantic depth in housing design. The important point is the quality of applying these components and providing a context in which the person can be able to mentally concentrate and understand the concepts of components of the AAN. The results of the present study confirm that observing the principle of spatial hierarchy which separation of areas, installation of filter spaces, and control of visual communication between areas are its architectural indicators alongside applying the transparency component are key factors in improving the quality of semantic depth in Iranian urban housing design. This rela- tionship can be interpreted from this perspective that observance of the principle of the spatial hierarchy provides the necessary basis for the mental preparation of residents to understand the semantic layers resulting from the presence of other semantic components of the architec- tural application of nature. Transparency is also the most important factor in creating a visual connection between residents and aspects of nature from the interior spaces. Therefore, it is another key component in improving the quality of semantic depth in housing architecture. Based on the importance of each component of the AAN in improving the quality of semantic depth in housing design, the following strategies and tactics are proposed in the design of con- temporary urban housing. Table 6 Proposed strategies and tactics to enhance the semantic depth quality in housing design based on the importance of semantic components of the AAN (Source: authors) Semantic components of the AAN Strategies Tactics H ie ra rc hy Observing the spatial hierarchy concerning access from public spaces to private spaces Designing neighborhood units and semi-public and semi-private spaces at the neighborhood level Observing the visual privacy of indoor spaces in apartment complexes Functional and visual separation of the areas at the residential unit level Avoiding the placement of the openings of residential units in front of each other Blocking the direct sight of the entrance to other indoor spaces by using Hashti. Considering the proper depth for terraces Observing the visual privacy of the courtyards and interiors in single-family houses Avoiding the access of strangers to the courtyard by applying height restrictions on the residential urban fabric and arranging for openings Providing visual privacy by planting Avoiding direct sight from the entrance to the yard Functional and visual separation at home level Tr an sp ar en cy The dominance of space over mass Creating porosity in architectural volumes Continuity of visual corridors Visual communication between interior and exterior spaces by using appropriate openings Visual continuity in the separation of interior spaces 63 Journal of Sustainable Architecture and Civil Engineering 2022/1/30 Semantic components of the AAN Strategies Tactics P ri m ar y ap pe ar an ce Avoiding blocking visual corri- dors to natural elements Suitable designing of the residential urban fabric to maintain the visual communication of the house with the sky and other natural elements Planting trees and plants in the yard and making it possible to communicate with them Using suitable openings to maintain the visual commu- nication of the main spaces with the plants and trees in the courtyard of single-family houses H on es ty Observing the principle of honesty in designing form and details Avoiding the use of vain elements without a structural or functional role in the building Coordinating building facades, dimensions of openings, materials, etc. with interior spaces Avoiding unnecessary decoration U ni ty Creating harmony in the resi- dential urban fabric in terms of form, the orientation of build- ings, density and occupancy area Developing appropriate regulations regarding compli- ance with occupancy and density Observing the geometrical proportions between different elements Residential units separation and building design based on appropriate base modules Observing the geometrical proportions between different elements Residential units separation and building design based on appropriate base modules A bs tr ac ti on ap pe ar an ce The application of abstract appearance of nature Designing patterns based on the abstraction of nature References Adeli, S. 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About the Authors MOHAMMADHOSSEIN AZIZIBABANI Ph.D. Student in Architecture Department of Architecture, Faculty of Arts, Tarbiat Modares University, Tehran, Iran Main research area Affordable Housing Design, Sustainable Design Address Faculty of Arts, Tarbiat Modares University, Tehran, Iran Tel. +989120929844 E-mail: M.azizibabani@modares.ac.ir MOHAMMADREZA BEMANIAN Professor at the Department of Architecture Faculty of Arts, Tarbiat Modares University, Tehran, Iran Main research area Iranian Islamic architecture, Architectural planning and management Address Faculty of Arts, Tarbiat Modares University, Tehran, Iran Tel. +98(21)82883711 E-mail: Bemanian@modares.ac.ir This article is an Open Access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 (CC BY 4.0) License (http://creativecommons.org/licenses/by/4.0/).