The Role of Biophilic Interior Design in Enhancing Social Sustainability in Shopping Malls: A User-Based Study

2.1 Biophilic design theory

Biophilic design theory emerges from the concept of biophilia, which refers to the innate human tendency to seek connections with nature. According to recent review studies by Tekin et al. and Wijesooriya et al. [13, 14], biophilic design is rooted in Wilson’s notion of biophilia and was subsequently developed and expanded within the field of design through the work of Kellert and colleagues. Building on this foundation, Browning et al. and Ryan et al. [4, 15] advanced the theory through the 14 Patterns of Biophilic Design, which organize design strategies into three categories (Figure 1): Nature in the Space (direct presence of vegetation, water, and daylight), Natural Analogues (use of materials, textures, colors, and patterns that mimic natural forms), and Nature of the Space (spatial configurations such as prospect, refuge, and complexity that evoke natural experiences).

tu_pian_1.png

Figure 1. 14 patterns of biophilic design (adapted from [4])

These patterns provide a practical guide for designers, linking empirical evidence of nature’s restorative effects to architectural applications.

Several subsequent reviews have indicated that the 14 Patterns is one of the most inclusive frameworks available and offers many ways in which designers can incorporate design strategies that will elicit positive physical (physiological), cognitive, and psychological reactions [14]. Commercial environments have been increasing their use of biophilic elements in order to create comfortable environments that will help to decrease users' levels of stress and increase their level of satisfaction [16], thereby placing biophilic design at the intersection of aesthetics and functionality for creating sustainable interior spaces.

2.2 Social sustainability in the built environment

Social sustainability refers to the capacity of built environments to support human well-being, inclusivity, and community cohesion. Unlike environmental and economic sustainability, it remains less defined, yet it is critical in shaping equitable and resilient societies. Scholars emphasize that socially sustainable spaces foster belonging, encourage participation, and enhance quality of life, making it a vital dimension of sustainable architecture.

In identifying indicators of social sustainability, Kefayati and Moztarzadeh [17] found social interaction, architectural identity, security, flexibility, and participation to be fundamental characteristics of incorporating social sustainability into architectural designs. Similarly, Lami and Mecca [18] suggested that equity, social networks, well-being, safety, and design identity are also important considerations; authors further emphasize that culturally responsive and inclusive spaces will have a positive impact on the quality of life [19].

Collectively, these studies confirm that accessibility, cultural sensitivity, identity, and psychological comfort are indispensable dimensions of socially sustainable built environments across different architectural scales.

2.3 Social sustainability in interior architecture

Extending this discourse to interior environments, previous studies highlight that interior design plays a significant role in supporting social sustainability. Altamimi et al. [20] demonstrate that workplace interiors influence social sustainability through spatial qualities related to comfort, privacy, social interaction, and spatial organization, highlighting the importance of indoor environmental quality in promoting collaboration, inclusion, and user satisfaction. Similarly, in housing contexts, Ebbini and Bleibleh [21] emphasized that sense of place, dignity, and social belonging are essential factors shaping residents’ well-being, underscoring the need to integrate social and psychological considerations into the evaluation of interior environments.

2.4 Shopping malls as social spaces

Shopping malls are rapidly changing from just retail stores into multi-use spaces for social gathering. This change is evidenced by shopping malls being "third places” for people to go and meet each other outside of their homes or workplaces. The research shows that interior space design has a large impact on these experiences. How people interact with one another, whether they feel included, and how they experience a space are all influenced by the way that space is designed, including how it is laid out, how people circulate through it, what kind of environmental conditions exist in it, and what kinds of communal spaces exist in it [22].

Biophilic design can further amplify the social aspects of an interior space. As demonstrated in studies conducted in Surabaya and Kuwait, incorporating natural elements, such as green walls, water features, daylight, and organic shapes, reduces stress, increases well-being, and promotes restorative experiences in shopping malls [22, 23]. Furthermore, empirical evidence supports that biophilic malls are perceived as being more attractive, restorative, and socially interactive by shoppers, thus increasing their likelihood to visit again and refer friends and family [24]. Similarly, Rosenbaum et al. [25] found that lifestyle centers (shopping malls that have been designed to provide additional amenities, such as gardens, fountains, and natural lighting) act as transformative services capes that provide opportunities for prolonged social interaction and relief from mental fatigue.

Therefore, shopping malls that incorporate biophilic elements expand their use beyond commerce to become important urban social spaces. By creating environments that promote restoration, socialization, inclusion, and community cohesion, shopping malls serve an increasingly significant role in providing sustainable and socially responsible centers in today's cities.

2.5 Previous empirical studies

Existing empirical research continually illustrates how biophilic design positively impacts human health and wellness across different types of buildings. For example, when it comes to healthcare environments, there is a significant body of evidence showing that adding natural light, plants, water features and using natural products in the built environment, all contribute to reducing stress, creating healthy environments for healing and improving patient satisfaction; and overall support the use of multisensory and environmentally responsive designs that support physiological and psychological recovery [26, 27].

In addition, biophilic strategies have been used successfully in hospitality settings to create better indoor environmental quality, comfort, user satisfaction, and encourage users to spend more time in those spaces and engage in positive behaviors [1, 28-30]. Similarly, researchers have also demonstrated that biophilic elements such as skylights, vertical gardens, and water features in commercial environments create better sensory experiences and support the emotional well-being of visitors, and ultimately lead to increased levels of visitor engagement. Restorative experiences are further related to increased lengths of visit and consumers' positive behaviors [23, 24, 31, 32].

While numerous studies have investigated the effects of biophilic design in individual functional contexts and the resultant psychological/behavioral outcomes, relatively little research exists regarding the relationships between biophilic design and social sustainability measures, including inclusiveness, sense of place, and community engagement—specifically in shopping mall environments. Therefore, this study seeks to address this research gap by conducting comparative, user-based research that investigates the relationships between specific biophilic interior design strategies and social sustainability measures in shopping malls. Malls are environments where collective experiences and community-oriented spaces can provide greater societal impact than other environments.

2.6 Research gap

Biophilic design has been demonstrated to enhance both the psychological comfort of occupants and their overall satisfaction; however, research focused on shopping malls primarily examines a consumption-based focus. Specifically, previous research has examined the ability of biophilic design to promote a restorative experience for shoppers as well as positively affect retail performance, yet has neglected to address the broader social sustainability outcomes of this type of environment. Although social sustainability includes aspects such as inclusivity, social interaction, sense of place, comfort, and perceived safety, the theoretical foundation is rare in terms of its implementation within interior design research focused on commercial environments.

Additionally, prior research has rarely investigated which specific biophilic interior design dimensions contribute to social sustainability. As a result, the differentiated impacts of Nature in the Space (direct natural elements), Natural Analogues (materials, textures, and forms), and Nature of the Space (spatial configuration, openness, and prospect–refuge) have rarely been investigated in comparison to measurable social sustainability indicators. In general, comparative, quantitative examinations of the linkages among these three dimensions and users' social perceptions in shopping malls are very limited. This provides evidence of a research gap that indicates the need for empirical research that specifically links each of the three biophilic interior design dimensions to social sustainability outcomes in shopping mall environments.

In this study, a quantitative comparative approach was used to establish the connection between the use of biophilic interior design elements and social sustainability within shopping malls. In order to improve the credibility of the findings and minimize the possibility of single-source bias, the research utilized mixed methods for collecting the data by combining systematic observation with surveys assessing the users' perception of the malls. The focus of the comparative analysis was made on three different shopping malls located in the same urban environment (the city of Erbil), to control contextual variables while capturing variation in the extent and type of biophilic interior design implementation.

4.1 Case study

A comparative case study approach was adopted to evaluate shopping malls with different levels of biophilic interior integration. Three major shopping malls in Erbil, Kurdistan Region of Iraq—Grand Majidi Mall, Family Mall, and Gulan Mall, were purposively selected (Figure 3). The selection criteria included:

(1) Scale and multifunctional role as major commercial and social spaces.

(2) High accessibility and diverse user groups.

(3) Variation in the degree of biophilic interior design implementation. This approach enabled a controlled comparative analysis while maintaining contextual consistency across the selected cases.

tu_pian_3.jpg

Figure 3. Case study locations on the Erbil City map

Erbil was selected as the study context due to its rapid urban development and the increasing role of shopping malls as primary social and recreational destinations. The selected malls represent some of the most prominent and frequently visited commercial centers in the city, making them appropriate cases for examining user experience and spatial qualities within a consistent urban context.

4.2 Data collection

Data were collected using two complementary methods:

1. Structured observation.
2. Questionnaire survey.

The observation checklist was developed based on existing literature on biophilic design principles and specifically the 14 patterns of biophilic design. Standardized evaluation criteria were adopted to ensure consistency in measuring biophilic qualities across all cases. quality was scored using a rating scale ranging from (1 = absent/very weak to 5 = strongly present). Observations were conducted at three time periods (morning, afternoon, and evening) to capture temporal variations in environmental conditions, including daylight availability, visitor density, and activity levels. The same observational procedure was applied across all case studies to ensure comparability.

The second stage of data collection involved the use of questionnaires that were distributed to users of the shopping malls to assess their perceptions of biophilic qualities and social sustainability. The questionnaires were distributed both online and in-person to obtain a representative sample of users. The sampling technique used was non-probability convenience sampling. In total, 151 responses were collected, all of which were complete and valid for analysis.

4.3 Measurement and instrument development

Survey items were developed based on established literature on biophilic design and social sustainability. Biophilic perception was operationalized through three constructs: Nature in the Space, Natural Analogues, and Nature of the Space. Social sustainability was measured using four indicators: Social interaction and participation, Inclusivity and accessibility, psychological and physical comfort, and perceived safety and well-being.

Psychological and physical comfort was defined as users’ perceived environmental and emotional ease within the interior space, influenced by factors such as lighting quality, thermal conditions, noise levels, and spatial organization. Perceived safety and well-being referred to users’ feelings of security, relaxation, and overall well-being within the shopping mall environment [18, 21]. Social interaction and participation reflected the extent to which the interior environment encouraged communication, social engagement, and communal activities among users, while Inclusivity and accessibility referred to the degree to which the space accommodated diverse user groups and promoted equal access to facilities and services.

These indicators were selected based on their consistent identification in the literature as core dimensions of social sustainability in the built environment. They reflect key aspects of user experience in interior spaces, particularly in commercial settings, where factors such as comfort, inclusivity, social interaction, and perceived safety play a significant role in shaping overall spatial satisfaction and user well-being. All items were measured using a five-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). Prior to distribution, the questionnaire was reviewed to ensure clarity and face validity, and minor revisions were made to improve comprehensibility and reduce ambiguity.

The final questionnaire items are presented in Appendix A, including Nature in the Space (Table A1), Natural Analogues (Table A2), Nature of the Space (Table A3), social interaction and participation (Table A4), inclusivity and accessibility (Table A5), psychological and physical comfort (Table A6), and perceived safety and well-being (Table A7).

4.4 Reliability and internal consistency

Internal consistency reliability was assessed using Cronbach’s alpha coefficient for each construct. Cronbach’s alpha values of 0.70 or above are generally considered acceptable; however, lower values may be tolerated in exploratory studies within the social and built environment fields. Following the initial reliability assessment, the construct "Sense of Place & Identity" was excluded from further analysis due to its extremely low reliability (α = 0.178), indicating insufficient internal consistency among its items. The remaining constructs were retained for subsequent analyses after scale refinement. The final reliability results are presented in Table 2.

Table 2. Reliability results (Cronbach’s alpha)

Although some constructs yielded Cronbach’s alpha values slightly below the commonly recommended threshold of 0.70, they were retained because the study is exploratory in nature and the scales were adapted from previous literature to suit the shopping mall context. Several methodological studies have noted that reliability coefficients between 0.50 and 0.70 may be considered acceptable in exploratory social science and built environment research, particularly when constructs consist of a limited number of items. Therefore, the retained constructs were considered sufficiently reliable for subsequent correlation, regression, and comparative analyses. The final questionnaire items retained after scale refinement are presented in Appendix A.

4.5 Data analysis

Quantitative data were analyzed using the IBM Statistical Package for the Social Sciences (SPSS) Statistics. Descriptive statistics including Frequencies, percentages, means, and standard deviations, were used to summarize respondent characteristics and key variables. One-way analysis of variance (ANOVA) was conducted to examine differences between the selected shopping malls, followed by Tukey post-hoc tests where significant differences were identified. Pearson correlation was used to determine the association between biophilic design and social sustainability variables. Regression analysis was performed to evaluate the predictive contribution of biophilic design variables on social sustainability.

Before interpreting the regression model results, key assumptions were examined, include normality of residuals, homoscedasticity, independence of errors, and multicollinearity. All assumptions were satisfied within acceptable ranges. Homoscedasticity was confirmed through residual scatterplots. While normality was verified using Q-Q plots and the Shapiro-Wilk test. Independence of errors was supported by the Durbin-Watson statistic 1.970. Multicollinearity was not a concern, as Variance Inflation Factor (VIF) values ranged between 1.945 and 2.399 and Tolerance values between 0.417 and 0.514.

This section discusses the key findings of the study by interpreting the relationship between biophilic interior design and social sustainability in shopping mall environments, with reference to biophilic design theory and social sustainability literature.

6.1 Interpretation of key findings

The findings of this study provide empirical evidence that biophilic interior design contributes positively to social sustainability in shopping malls; however, the degree of influence varies across different biophilic design dimensions. Among these dimensions, nature of the space emerged as the most influential factor in shaping users’ perceptions of social sustainability. The spatial characteristics of interior spaces, such as openness, visual depth, legibility of circulation paths, and prospect-refuge conditions, are the aspects of the physical environment that contribute to an individual’s sense of safety, comfort, and connection to a given environment. It follows that socially sustainable interiors are largely influenced by the way space is organized and experienced rather than simply through the incorporation of natural elements. From a practical perspective, this finding suggests that designers should prioritize spatial configuration strategies, such as openness, visual connectivity, and clear circulation systems over the mere addition of decorative natural elements. In commercial environments like shopping malls, these spatial qualities enhance users’ sense of orientation, safety, and comfort, thereby supporting more inclusive and socially interactive environments.

The findings of this study support the theoretical underpinnings of biophilic design proposed by Browning et al. [4]. Specifically, the Nature of the Space pattern types, which identify the importance of spatial experiences that mimic those of the natural environment for psychological restoration and well-being. In the context of shopping malls, coherently organized space encourages intuitive movement and visual connectivity resulting in prolonged time spent in the environment thus creating a socially supportive environment. In addition to enhancing users' sense of comfort and emotional attachment to interior spaces, natural materials, organic forms and nature inspired textures also have a positive impact on the psychological experience of the interior environment. Given the constraints associated with incorporating large amounts of vegetation or water features into commercial interior space settings, the use of indirect representations of nature are especially valuable.

Finally, whereas the use of natural elements in the space (i.e., vegetation, water features, and daylight) are highly valued by users of shopping malls, the results of this study suggest that their ability to predict social sustainability is contingent upon their spatial integration. Thus, while users perceive these elements as having a positive impact, it appears that the inclusion of these elements functions as supplementary components of social sustainability in the shopping mall setting, rather than primary drivers of social sustainability, especially if they are incorporated in a decorative or fractured manner. Overall, the findings of this study indicate that social sustainability of shopping malls is more significantly impacted by the quality of the spatial experience generated by the application of biophilic design principles, rather than the amount of biophilic elements that are utilized. Therefore, biophilic design approaches that prioritize spatial coherence and experiential continuity are more likely to create commercially inclusive, comfortable, and socially sustainable environments.

6.2 Theoretical and practical contributions

The theoretical contributions of this study provide empirical evidence for a connection between biophilic interior design and social sustainability in shopping mall spaces. In contrast to much of the prior literature, the results of this study demonstrate how biophilic design is a key component of social sustainability in terms of inclusivity, sense of community, and perceived safety, three important aspects of social sustainability. The practical implications of this study are that designers and other decision makers should place a greater emphasis on developing and using space planning principles based upon nature (using analogues of natural forms, materials, and processes) to create spaces with open views, continuous sightlines, clear paths through buildings and prospect/refuge spaces instead of simply decorating spaces with biophilic elements. If designers incorporate these principles into their designs, it could lead to shopping malls being able to act as commercially viable, but socially sustainable, urban interiors. These findings reinforce the argument that biophilic design should be approached as an integrated spatial strategy rather than a collection of isolated natural elements.

6.3 Limitations and future research

This study has several limitations. First, the sampling method employed was a non-probability convenience sampling approach, and the study was limited to three shopping malls within a single city, which may restrict the generalizability of the findings to other urban contexts. Second, the cross-sectional nature of the study captures users’ perceptions at a single point in time and does not account for potential changes in perceptions resulting from repeated exposure to biophilic environments. Longitudinal studies could provide deeper insights into how users’ social experiences evolve over time.

Third, although the use of a structured observation checklist contributed to methodological triangulation, some degree of subjectivity may remain in the evaluation process. Future studies may strengthen reliability by incorporating inter-rater reliability assessments and objective environmental measurements, such as daylight levels, vegetation coverage ratios, thermal comfort indicators, and acoustic performance metrics. Future studies may expand the research to different urban contexts and commercial environments while employing larger and more diverse samples.

In addition, advanced analytical techniques such as Structural Equation Modeling (SEM), Partial Least Squares Structural Equation Modeling (PLS-SEM), or PROCESS-based mediation analysis could be used to investigate whether psychological and physical comfort, perceived safety and well-being, and social interaction mediate the relationship between biophilic design dimensions and broader social sustainability outcomes. Such approaches would provide a more comprehensive understanding of the mechanisms through which biophilic interior design contributes to social sustainability.

We sincerely thank all survey participants and the management of the malls in Erbil for their cooperation. Their support and contributions made this study possible.