Introduction: Traditional Iranian architecture is founded upon climatic and environmental conditions as well as deep cultural and spiritual values rooted in Iranian-Islamic beliefs. Among these, the principle of privacy "MAHRAMYYAT" holds a foundational position. Derived from religious teachings and Iranian social culture, privacy is a multidimensional concept possessing both semantic and physical dimensions: semantically it preserves dignity, seclusion and psychological security; physically it is realized through hierarchical spatial organization, definition of territories and domains, inward-oriented design and controlled spaces.
The dialectic between the cultural value of privacy and its physical manifestation creates a two-way relationship: cultural values shape architectural spaces, while spatial organization reproduces and sustains those values. Although valuable studies have addressed privacy mechanisms and the transformation of traditional houses, the specific dialectic between the principle of privacy and the spatial-physical structure—especially in the temperate-humid climate of northern Iran—has received less attention. Gilan Province, with its distinct climatic and cultural characteristics along the southern Caspian coast, provides a rich setting for examining this dialectic in Qajar-period urban houses, which display relative introversion, hierarchical access and measured connection with nature as expressions of privacy.
The present study re-reads this dialectic in Qajar traditional houses of urban Gilan. The central research question is: How effective are the indicators of privacy in shaping the spatial-physical structure of traditional houses in Gilan Province during the Qajar period?
Research Method: The research is mixed-methods (qualitative–quantitative) with a descriptive-analytical and applied approach. In the qualitative phase, privacy indicators and spatial-physical components were first extracted through library and documentary studies. To refine them for the Gilan context, semi-structured interviews were conducted with 15 local experts in architecture and urbanism; the selected houses (10 out of 30 registered Qajar houses) were presented to interviewees. Interview data were analyzed using grounded theory (Strauss and Corbin approach) through open, axial and selective coding in MAXQDA software. Codes repeated three to six times were selected as core variables, resulting in five second-order privacy indicators and five first-order spatial-physical components.
In the quantitative phase, these variables were converted into a 30-item five-point Likert questionnaire (10 items for privacy indicators, 20 for spatial-physical components). The questionnaire was distributed to 82 specialists (university professors, researchers and architects experienced in Gilan traditional houses) in three Delphi rounds. Consensus was reached in the third round (Kendall’s coefficient of concordance > 0.7). Reliability was confirmed by Cronbach’s alpha and composite reliability; convergent validity by AVE (>0.5) and factor loadings (>0.7); discriminant validity by the Fornell–Larcker criterion. Data were analyzed using SPSS and Smart PLS 3 through structural equation modeling. The ten selected Qajar houses served as the contextual sample.
Theoretical Foundations: The concept of privacy originates from the Persian-Islamic term harem, denoting a protected domain whose boundaries must be defended. It refers to a state free from unwarranted intrusion that enables control over one’s environment and regulation of social interactions. In traditional Iranian housing, privacy constitutes the fundamental function of the dwelling. Five indicators operationalize this principle: spatial hierarchy (organization of spaces according to physical or functional characteristics creating graded access, use and visibility); introversion (centering the building around one or more semi-private courtyards that separate it from the outside world, with only controlled entrances); territory and domain (increasing individual or group freedom of choice and control over activities); siting (minimal integration between guest and private spaces, fully separated in plan); and zoning (functional separation of private and public areas so that one does not affect the other while allowing simultaneous use).
These cultural-semantic indicators interact dialectically with the spatial-physical components of the house: spatial organization, transparency and connection to nature, facade and ornamentation, form/geometry/dimensions, and construction techniques/materials. Following Rapoport (1969) and Lang (1987), architectural space results from the interaction between cultural and physical systems. Privacy, as an endogenous cultural principle, shapes spatial patterns while those patterns reproduce and reinforce the cultural value. In Gilan, this dialectic manifests as a dynamic balance between the cultural demand for seclusion and the climatic requirements of the humid, verdant environment, producing a distinctive regional architectural identity.
Discussion and Findings: Structural equation modeling showed that all five privacy indicators exert positive and statistically significant effects on the formation of spatial-physical components (t-values > 1.96, p < 0.05). The overall model possesses strong goodness-of-fit (GOF = 0.391). Among the indicators, territory and domain exerted the greatest influence on spatial organization; introversion showed the highest significant coefficients with facade and ornamentation, form, geometry and dimensions; and zoning displayed the strongest relationship with construction techniques and materials.
Detailed path analysis confirmed that hierarchy had its strongest effect on transparency and connection to nature (β = 0.332), reflecting graded courtyards and "IVAN" as mediators. Introversion most strongly influenced facade and ornamentation (β = 0.370) and form/geometry/dimensions (β = 0.299), manifesting in controlled openings such as "OROSI" lattice windows and enclosed volumes. Territory and domain primarily shaped spatial organization (β = 0.302) through separation of "ANDARUNI" and "BIRUNI" zones. Siting affected construction techniques and materials (β = 0.240) by guiding climate-responsive material selection. Zoning most strongly impacted construction techniques/materials (β = 0.370) and facade/ornamentation (β = 0.364), producing differentiated palettes across functional realms.
Reliability (Cronbach’s alpha and composite reliability all > 0.7) and validity (AVE > 0.5, Fornell–Larcker criterion satisfied) were fully confirmed. R² and Q² values indicated acceptable explanatory and predictive power. These results demonstrate that privacy in Qajar Gilan houses operated as a generative mechanism: cultural imperatives produced layered facades, multi-functional iwans, high boundary walls and climate-responsive envelopes that simultaneously secured seclusion, psychological comfort and harmonious dialogue with nature. The dialectic is thus concrete—cultural values shape built form, while built form sustains and perpetuates those values.
Conclusion: The aim of this study was to examine the role of privacy in the formation of the spatial-physical structure of Qajar-period traditional houses in Gilan Province. The results indicate that privacy was one of the most effective factors in the organization of space, architectural form and the relationship of the house with its surroundings during this period. Examinations show that the various components of privacy, acting in harmony and interaction with one another, played a decisive role in shaping the pattern of traditional houses in Gilan.
Findings reveal that introversion and attention to family seclusion manifested more than other factors in the appearance and structure of the houses. Focus on internal spaces, use of interior ornamentation, controlled openings and enclosed walls expressed the inhabitants’ desire to preserve personal privacy and reduce direct external views. Consequently, Gilan houses, despite their connection with nature, maintained clear visual and functional boundaries. Spatial division into public, semi-private and private realms played a major role in realizing privacy; this division influenced not only usage but also material selection and decoration, creating distinctions among different areas of the house. Definition of territory and domain through separation of "ANDARUNI" and "BIRUNI" zones and control of sight lines constituted another key mechanism.
Placement of the building within the urban fabric and its relation to climatic conditions were also influential: site selection, orientation and use of local materials were carried out in accordance with the humid climate while preserving privacy. Although hierarchy and siting played complementary roles, their impact was less than that of introversion, zoning and territory. In sum, privacy in the traditional houses of Gilan was not merely a cultural or social concept but an effective mechanism for shaping space, physical fabric and architectural identity. The interaction between privacy, climate and local culture produced patterns such as enclosed spaces, iwans, lattice windows and multi-layer walls—patterns that, while providing calm and seclusion, established a balanced connection between the interior of the house and the surrounding nature. These findings can be utilized in recognizing indigenous architectural values and applying them to contemporary design in northern Iran.