Biophilic Architecture in the Livable City of Melbourne CBD

Abstract

Amid continuous urban population growth and urbanization’s environmental and social challenges, livable cities have become a key priority for governments. Among the various factors influencing urban livability, architectural design integrating natural elements plays a critical role. Melbourne consistently ranks as one of the world’s most livable cities, with its Central Business District (CBD) serving as its core. Since a previous study has highlighted a research gap concerning the role of architecture in livable cities and indicated that the characteristics of biophilic architecture remain unclear, this study addresses the following question: What are the attributes of biophilic architecture in the CBD of the livable city of Melbourne? Subsequently, buildings exhibiting characteristics of Biophilic architecture were surveyed, and photographs capturing the most representative aspects of each building were documented. These characteristics were then coded and analyzed using statistics. The study found that Biophilic architecture is extremely rare in Melbourne’s CBD, with only four of 6375 properties (0.06%) identified as such. The most prominent attributes include connection to nature, natural color tones, and light modulation shaped by the city’s grid layout and strong sunlight. However, the dominance of concrete structures and heritage regulations constrains formal diversity. While Melbourne may not provide abundant examples, its context offers valuable insight into how urban form and policy shape biophilic expression. Future studies should extend this comparative approach to other cities to better understand context-specific adaptations of biophilic design.

1. Introduction

According to the United Nations, the global population is projected to continue increasing steadily over the next 50 years [1]. At present, more than half of the world’s population resides in urban areas [2]. Moreover, within the next 25 years, nearly 70% of the global population is projected to live in cities [3,4,5]. As a result, urban areas have expanded rapidly over the past few decades, and the total area of cities has multiplied [6,7]. These factors not only represent a positive growth trend but also serve as a warning of the negative impacts that may unfold in the coming years.

Rapid urbanization has far-reaching environmental consequences. It begins with the loss of natural habitats, which contributes to declines in biodiversity, drives deforestation, and leads to the degradation of green areas [8,9]. The impacts of urban expansion are not limited to wildlife and natural ecosystems. Today, it is evident that these environmental consequences inevitably reverberate back to affect human health [10]. Urbanization can exacerbate mental health issues, including anxiety, depression, and social isolation, which in turn negatively impact populations’ well-being [11,12,13].

Given the unstoppable growth of urban areas, creating livable cities has become a key objective of urban development in many countries worldwide and has attracted increasing attention from policymakers and urban governance [14,15,16]. This concept positively impacts both urban sustainability and the well-being of residents [17,18,19]. Achieving this goal requires consideration of various dimensions, including economic performance, life satisfaction, transportation, public safety, urban policy, urban health, urban planning, environmental sustainability, and architectural design [20].

Among the many factors that must be considered when developing livable cities, architectural design has emerged as one of the most frequently discussed aspects in efforts to enhance urban livability [20]. This is particularly important because highly developed and densely populated zones often have buildings covering more than 70% of the total area [21]. In addition, architectural design plays a key role in shaping urban sustainability and significantly impacts human well-being [22]. Therefore, this study focuses on exploring architectural design approaches that can promote the concept of livable cities.

Several studies indicate that biophilic architectural design contributes substantially to creating more livable cities [23,24,25,26]. Biophilic architecture refers to a design that integrates natural elements into the built environment [27]. A key rationale is that biophilic design represents a sustainable approach that contributes to both the sustainability and livability of urban environments [23]. Moreover, biophilic elements play a crucial role in promoting both physical and mental well-being [24,28,29], particularly in the context of high population density and urban expansion. Thus, biophilic design supports both environmental sustainability and the well-being of urban inhabitants, as summarized in Figure 1.

1.1. Research Area

Melbourne is particularly notable among the cities ranked as the most livable in the world. It is the only city to have held the number one position for the most extended continuous period, spanning seven years from 2011 to 2017 [30]. Although Melbourne has been ranked lower in recent years, it remains among the top five most livable cities according to the Economist Intelligence Unit report. Central Business Districts (CBDs) are the core functional areas of cities [31]. Therefore, this study selects Melbourne CBD as a representative livable city to investigate architectural characteristics that integrate biophilic elements.

1.2. Research Gap

As noted above, with the continuous growth of urban populations and the negative impacts of urbanization on both the environment and people, livable cities have become a key priority for government agencies in their urban development efforts. Although the development of livable cities involves many factors, architectural design is frequently highlighted and occupies a significant portion of metropolitan areas. Previous studies have shown that architecture integrating natural elements appears to have the most critical potential to enhance urban livability. The research has revealed that the role of architecture in fostering livable cities has often been overlooked [32]. Furthermore, a prior study points to a research gap arising from the insufficient clarity in understanding the characteristics of Biophilic architectural design [33]. Melbourne is the most consistently ranked livable city globally, and its Central Business District (CBD) serves as the city’s core. Building on this, this research aims to identify the specific attributes of biophilic architecture in a livable city. Thus, the research questions of this study can be summarized as follows: What are the characteristics of biophilic architecture in the CBD of the livable city of Melbourne? The findings of this research will serve as a report on the current status of biophilic architecture in Melbourne’s Central Business District (CBD), aiming to inform the development of design guidelines applicable to other urban contexts in the future.

1.3. Research Structure

The structure of this article is organized into eight main sections. The Section 1 introduces the research background and identifies the research gap that forms the foundation of this study. The Section 2 reviews the literature, identifying which biophilic architectural characteristics are most conducive to enhancing urban livability. The Section 3 describes the case studies selected based on this conceptual framework. The Section 4 outlines the research methods. The Section 5 presents the findings, highlighting quantitative results and statistical analyses. The Section 6 discusses these findings. The Section 7 identifies the research limitations and proposes directions for future research. Finally, the Section 8 concludes the study by summarizing its key findings.

2. Literature Reviews

This section reviews existing literature on the relationship between biophilic architecture and urban livability. It aims to synthesize previous research findings to identify how biophilic design contributes to enhancing the quality of urban life and which architectural characteristics most effectively promote livable cities.

2.1. The Impacts of Biophilic Architecture on Urban Livability

Previous studies indicate that specific categories of biophilic architectural elements will likely enhance urban livability [23,24,25,26]. A 2015 study also noted that biophilic architecture contributes positively to urban livability. To fully harness the benefits of such architecture, urban studies must incorporate a deeper understanding of biophilic design principles [34].

A review of studies on biophilic design and urban livability revealed clear evidence that biophilic urbanism, which promotes meaningful interactions between humans and nature, has a substantial impact on enhancing urban livability [35,36]. Moreover, the design of urban streets following biophilic principles has been found to influence users’ perceptions, spatial use, walking behavior, and overall quality of life [37].

Recent research has illustrated how biophilic design can be applied by integrating natural elements into urban spaces and transforming urban voids into nature-like environments. Architecturally, such design practices include creating sensory experiences, expanding garden and green areas, employing natural materials, and facilitating the visual and physical presence of nature within buildings, thereby contributing to improved urban livability [25].

It can be concluded that research on urban livability has predominantly focused on outdoor public spaces, such as green areas and streets, while studies addressing the architectural dimension remain limited. Thus, this literature review on biophilic architecture was conducted, focusing on identifying attributes that improve urban livability.

2.2. Biophilic Architectural Elements That Promote Urban Livability

Since this study aims to identify the characteristics of biophilic architecture that are expected to enhance urban livability, this part focuses on identifying the architectural elements most effective in establishing a connection with the urban environment.

From the literature review, it was found that explaining the relationship between architecture and the city, particularly in terms of how it contributes to the sense of urban livability, is rather complex, as it involves an overall atmosphere that emerges from multiple interacting spatial and sensory factors [38]. However, as this study aims to identify architectural characteristics that contribute to urban livability, the subsequent section examines the elements that shape the architectural atmosphere.

Previous studies have suggested that the architectural atmosphere emerges from the sensory perception of multiple interrelated elements, including form, space, movement, light, color, material, object, view, sound, and weather [39,40,41,42,43,44]. Since biophilic design has been defined in various ways, this review identifies and refines the architectural characteristics of biophilic design that hold the most significant potential for enhancing the urban environment. Specifically, these are elements visible from the exterior of buildings, representing the interface between architecture and the city, including form, space, material, color, and exterior lighting [45]. Therefore, the following section presents the characteristics of biophilic design in terms of form, space, material, color, and exterior lighting, as identified through the literature review.

2.3. Biophilic Architectural Characteristics That Promote Urban Livability

As the Biophilic Architectural Elements that are effective in enhancing the livability of cities are identified as form, space, material, color, and light, this section presents the characteristics of Biophilic Architecture according to these elements. Each category highlights how architectural features associated with biophilic design contribute to the improvement of urban livability within the context of Melbourne’s built environment.

Biophilic Forms can be summarized as exhibiting the following characteristics: they reflect biomimicry [33] and biomorphic design principles [46,47,48], incorporating nature-inspired [48,49] and biophilic design approaches [49]. Such forms often demonstrate natural forms [33,46,48,49,50,51], shapes [33,46,49,50,51], patterns [33], and non-rectilinear geometries [50], emphasizing a biophilic ratio [47] that harmonizes built structures with natural esthetics.

Biophilic Spaces can be summarized as possessing the following characteristics: they provide exposure [52,53] and connection to nature [33,46,47,49,52,54,55], as well as a connection to place [33]. These spaces often include transitional areas [50,51], reflect the principles of prospect and refuge [33], and emphasize connectivity and order [46] within their spatial organization. Additionally, they support an indirect nature experience [56] and promote a sense of spaciousness [50].

Biophilic Materials can be summarized as exhibiting the following characteristics: they resemble natural substances such as clay or concrete [57] and employ natural materials [33,46,47,49,50] that emphasize a connection with nature [55]. They often feature translucent [33] or indigenous qualities [50], natural textures [33,46,49,51], including biomorphic patterns [46,47,55], botanical motifs [50], and animal motifs [50]. Moreover, biophilic materials incorporate permeable surfaces [47] and are arranged with textures and colors that harmonize with the surrounding environment [33].

Biophilic Colors were characterized by attributes such as natural colors [33,46,47,49,50,51], distinct hues [57], complementary contrasts [50], and the effects of aging and patina [50,51].

Biophilic Lighting was characterized by the following attributes: natural light [33,46,47,49,50,51,55], spectral and ambient qualities [33], light incorporating nature [33], contrast of light and shadow [47,50], lighting control and refuge effects [33], light rays and lines [57], filtered and diffused light [50], dynamic and diffused light [33,46], reflected light [50], light pools [50], white light [57], warm light [50], and spotlights [57].

From the discussion mentioned above,

Table 1. The Expected Characteristics of Biophilic Architecture for a Livable City.

Architectural Elements	Architectural Characteristics
Biophilic Forms	Biomimicry, Biomorphic Design, Nature-Inspired Design, Biophilic Design, Natural Forms, Natural Shapes, Natural Patterns, Non-Rectilinear Geometries, Biophilic Ratio
Biophilic Space	Exposure to Nature, Connection to Nature, Connection to Place, Transitional Space, Prospect and Refuge, Connectivity and Order, Indirect Experience of Nature, Spaciousness
Biophilic Material	Clay or Concrete, Natural Materials, Connection with Nature, Translucent Qualities, Indigenous Qualities, Natural Textures, Biomorphic Patterns, Botanical Motifs, Animal Motifs, Permeable Surfaces, Harmonized with the surrounding environment
Biophilic Color	Natural Colors, Distinct Hues, Complementary Contrasts, Aging and Patina Effects
Biophilic Light	Natural Light, Spectral and Ambient Qualities, Light Incorporating Nature, Contrast of Light and Shadow, Lighting Control and Refuge Effects, Light Rays and Lines, Filtered and Diffused Light, Dynamic and Diffused Light, Reflected Light, Light Pools, White Light, Warm Light, Spotlights

summarizes the characteristics of biophilic architecture that tend to promote urban livability. These attributes serve as a framework for exploring biophilic architecture in Section 3 and decoding its characteristics within the Melbourne CBD in Section 4.

3. Case Study

To address the research question, a comprehensive survey of buildings within the Melbourne CBD was conducted to identify the presence of biophilic architecture. The five researchers’ team conducted the survey by identifying buildings that exhibited the characteristics summarized in Table 1. The data collection was carried out between 4 June and 24 June 2025. As a result of the survey, four buildings were identified as fitting the defined criteria. The percentage of agreement among the research team members on whether each building represented biophilic architecture is presented in

Table 2. Agreement Analysis of Biophilic Architecture in Melbourne CBD.

Biophilic Architecture	Rater					Average	SD	Percent of Agreement
	R1	R2	R3	R4	R5
CLLIX Australia 108 Apartments	5	5	5	5	5	5.00	0.00	100.00
Melbourne Quarter	3	4	3	4	3	3.40	0.49	75.50
Council House 2	2	2	2	3	4	2.60	0.89	55.50
Pixel Building	1	1	1	1	1	1.00	0.00	100.00

.

According to Table 2, the Pixel Building received a relatively low level of agreement among the researchers concerning its classification as biophilic design. Nevertheless, as several sources have identified Pixel as a representative example of biophilic architecture [58,59,60], it was decided to include this building in the subsequent stage of the research.

Consequently, CLLIX Australia 108 Apartments, Melbourne Quarter, Council House 2, and Pixel Building were identified as the case studies for this investigation. Architectural features associated with biophilic design were documented through field notes and audio recordings during site observations. The recorded data were subsequently transcribed, with the key findings described below.

3.1. CLLIX Australia 108 Apartments

The survey of CLLIX Australia 108 Apartments identified only one Biophilic characteristic in terms of form, namely biophilic design. The building’s form integrates architectural structures with natural elements, specifically trees, into a unified composition. These forms can be observed from multiple façades of the building and are present only within the podium section.

The biophilic form of the building clearly creates a spatial quality that evokes a connection to nature. This characteristic also fosters a sense of connection to place, specifically linking the building to Melbourne’s natural surroundings and abundant urban greenery. The podium section of the building further integrates trees at a height corresponding to the canopy of street-side vegetation.

No materials indicative of Biophilic architecture were observed in this building.

The CLLIX Australia 108 Apartments exhibit the use of natural coloration, as the primary material of the building is blue-toned glass, which reflects both the color of the sky and the surrounding environment.

The use of glass as the primary material in the building clearly generates characteristics of reflected light, observable across the entire structure, which predominantly employs a single material.

Figure 2 illustrates the Biophilic architectural characteristics of CLLIX Australia 108 Apartments, situated in the livable city of Melbourne.

3.2. Melbourne Quarter

The design analysis of Melbourne Quarter reveals a clear application of biophilic form, which is evident from all viewpoints along the public streets. The front of the building features multiple tall, slanted cylindrical columns resembling tree trunks, supporting a large box-like volume densely filled with vegetation, thereby creating an overall impression of a giant cluster of trees. In addition, the building incorporates a large spiral staircase visible from the exterior, which aligns with biomorphic form, while the prominently curved and undulating shapes further represent characteristics of natural form.

The impression of being situated beneath a large cluster of trees gives Melbourne Quarter a spatial quality that evokes an indirect experience of nature. Moreover, it is the only building among all the surveyed cases that demonstrates a transitional space, created through a large open void at the front of the building, which visually guides and physically leads people into the interior of the development.

The building prominently employs concrete-like materials in its walls and floors, where the simplicity of these materials reinforces a sense of connection with nature. In addition, certain elements, such as the large ceiling panels, are constructed with wood-like materials, representing the use of natural materials.

The material selection of Melbourne Quarter results in a natural color palette, characterized by shades of gray, the green of vegetation, and tones of brown.

The large glazed panels containing vegetation at the front of the building generate a considerable amount of reflected light. However, other light characteristics are relatively difficult to observe, as the lower levels of the building lack solid walls and instead consist of expansive open voids.

The Biophilic architectural features of Melbourne quarter, located within Melbourne’s central business district, are presented in Figure 3.

3.3. Council House 2

The survey of Council House 2 revealed Biophilic characteristics in the aspect of form, specifically biomorphic design and natural form. These are expressed through the use of elongated cylindrical tubular structures with segmented joints resembling bamboo, extending to nearly the full height of the building on the southern façade adjacent to the public street.

In addition to the aforementioned formal characteristics, the building also demonstrates spatial qualities that evoke an indirect experience of nature. Specifically, the design creates the impression of being situated within a space lined with bamboo groves.

On all visible façades of Council House 2 from the public streets, concrete is the predominant material observed. On the front façade, which serves as a prominent architectural feature, a large-scale timber cladding is employed, representing the use of natural materials.

The large timber façade at the front of the building clearly imparts a natural coloration to the architecture. This characteristic is distinctly perceptible from the main frontage, including the wide pedestrian walkway and the adjacent major roadway.

Because Council House 2 incorporates a protective façade at the front and tall cylindrical tubes along the sides, the building produces pronounced hard light and shadow effects. The light falling on the building thus corresponds to filtered and diffused light characteristics. At the same time, the illumination observed on the façade itself is characterized as light filtered through surrounding trees and the shading of adjacent buildings.

The characteristics of Biophilic architecture in Council House 2, located in the livable city of Melbourne, are illustrated in Figure 4.

3.4. Pixel Building

Pixel, located in the northern part of Melbourne CBD, exhibits a biomorphic design in terms of form. The building features façades resembling layered leaf clusters on trees. Although the façades display a variety of shapes, they can collectively be described as leaf forms arranged in a natural pattern.

The leaf-like pattern formed by the overlapping façades of Pixel creates a spatial quality that evokes an indirect experience of nature. Specifically, the space resembles the canopy of a large tree.

While most of the building’s exterior is covered by large, multicolored leaf-like façades, certain viewpoints from public streets reveal the inner building envelope, which is composed of concrete.

The multicolored leaf-like façades of Pixel impart a natural color palette to the building. The natural hues include various shades of red, orange, and green, resembling leaves undergoing seasonal color change, which coincided with the period during which the site survey was conducted.

The unevenly sized leaf-like façades generate pronounced light and shadow effects from all viewpoints. As a result, most of the light reaching the building exhibits characteristics of filtered and diffused light.

The characteristics of Biophilic architecture in Pixel, located in the northern part of Melbourne CBD, are illustrated in Figure 5.

In summary, there are a total of 6375 properties, including 4641 commercial buildings (72.8%) and 274 residential buildings (4.3%) in Melbourne CBD. Among all these properties, only 4 buildings (0.06%) were identified as Biophilic architectures, highlighting the minimal presence of structures that incorporate natural elements into their design (Figure 6).

4. Methodology

To answer this question, the study adopted a qualitative research approach that combined visual observation and content analysis to identify and categorize the attributes of Biophilic design evident in selected architectural cases within Melbourne’s central business district (CBD). The methodology is organized into three main stages: data gathering, data coding, and data analysis, as described below (Figure 7).

4.1. Data Gathering

To ensure consistency and minimize observer bias, data collection followed a structured photographic protocol. The research team conducted site photography collectively, capturing each building from agreed-upon viewpoints to reflect authentic, human-scale visual perspectives. A standardized guideline specified camera height, viewing angle, time of day, and lighting conditions to maintain comparability across sites.

Three representative photographs per site were then selected through a consensus process based on predefined visual criteria in Table 1. To enhance reliability, inter-rater verification was conducted by jointly reviewing and confirming the representativeness of image sets before final selection. The finalized photographic samples employed for subsequent analysis are shown in Figure 2, Figure 3, Figure 4 and Figure 5.

All building attributes were recorded using a coded template in an Excel database, enabling traceability and replication of the analysis. All photographic data were securely stored in a restricted-access cloud drive available only to the research team, preventing unintended exposure or misuse of private spaces. To ensure privacy and ethical compliance, photographs were intentionally captured to avoid including identifiable individuals. In cases where people were incidentally present, their facial features were blurred before dissemination.

4.2. Data Coding

The visual data were coded according to the analytical framework developed from the literature review (Table 1) [61]. To enable systematic quantification of architectural attributes, a content analysis was conducted using Supervisely version 6.12.33 [62]. This platform allows consistent tagging and annotation of image features, enhancing reliability and traceability of results.

A coding protocol was jointly developed and executed by the research team, as the identified attributes were objective and countable rather than interpretive. This approach ensured that data coding reflected observable physical characteristics rather than subjective evaluations. Prior to the main analysis, a pilot coding session was conducted on a sample dataset to calibrate understanding and refine coding criteria.

During the primary process, all images were collaboratively reviewed, and coding decisions were made through group consensus to minimize individual bias. Inter-rater reliability was verified by cross-checking a subset of coded images among team members, achieving agreement before finalization. This approach, combining structured guidelines, collaborative verification, and digital traceability, enhanced the objectivity and replicability of the visual content analysis [63].

4.3. Data Analysis

Finally, descriptive statistics were employed for data analysis, as they provide a transparent and interpretable means of addressing the research questions. The statistical procedure was conducted in two stages: first, the number of occurrences of each attribute per viewpoint was summarized using counts (n), percentage (%), and cumulative percentage (%); second, an overall summary of all attributes was produced, reporting the most frequently observed features with mean, standard deviation (SD), minimum, and maximum values.

5. Results

This section presents the research findings, focusing on the application of biophilic design principles observed in the selected case studies. The results are categorized into five key architectural dimensions: form, space, material, color, and exterior lighting. These dimensions collectively reveal how biophilic characteristics are expressed through different aspects of architectural design.

5.1. Biophilic Form

The survey results on Biophilic architecture in Melbourne CBD, the livable city, indicated that four form characteristics, biophilic design, biomorphic design, natural form, and natural pattern, were observed.

Although more than half of the total images collected did not exhibit any characteristics of biophilic design form (n = 5, 41.70%), and one-third displayed only a single instance of such traits (n = 4, 33.30%), particular building perspectives revealed a much higher prevalence. Specifically, 2 images (16.70%) captured viewpoints showing as many as 13 distinct biophilic form points, while another image exhibited up to 16 points (8.30%) (

Table 3. The Result of Biophilic Form Analysis.

Biophilic Design	Counts (n)	% of Total	Cumulative %
0	5.00	41.70%	41.70%
1	4.00	33.30%	75.00%
13	2.00	16.70%	91.70%
16	1.00	8.30%	100.00%

).

Architectural form characteristics of biomorphic design were observed in 8 out of 12 images (66.70%). However, in each of these 8 images, the characteristic appeared only once per image (

Table 4. The Result of Biomorphic Design Analysis.

Biomorphic Design	Counts (n)	% of Total	Cumulative %
0	4.00	33.30%	33.30%
1	8.00	66.70%	100.00%

).

Natural form was observed to the same extent as the biomorphic design form. It appeared in 8 out of 12 images (66.70%), with each image showing the natural form only once (

Table 5. The Result of Natural Form Analysis.

Natural Form	Counts (n)	% of Total	Cumulative %
0	4.00	33.30%	33.30%
1	8.00	66.70%	100.00%

).

The form representing a natural pattern was observed in 8 viewpoints out of the 12 recorded images (66.70%). This indicates that the natural pattern was encountered to the same extent as the two previously mentioned characteristics, natural form and biomorphic design form (

Table 6. The Result of Natural Pattern Analysis.

Natural Pattern	Counts (n)	% of Total	Cumulative %
0	4.00	33.30%	33.30%
1	8.00	66.70%	100.00%

).

The research results indicate that the biophilic design form was the most frequently observed among the four observed architectural form characteristics: biophilic design, biomorphic design, natural form, and natural pattern. From the viewpoint showing the highest number of biophilic design forms, up to 16 distinct points could be observed. In contrast, the other form characteristics were observed at most only once per viewpoint (

Table 7. Frequency of Biophilic Form Features.

Biophilic Form Features	Mean	SD	Min	Max
Biophilic Design	1.00	0.00	0.00	16.00
Biomorphic Design	1.00	1.00	0.00	1.00
Natural Form	1.00	1.00	0.00	1.00
Natural Pattern	0.00	0.00	0.00	1.00

).

In addition, independent coding that did not rely on the framework developed from the literature review revealed additional form characteristics. These included Rectangular Form, Box Shape, Rectangular Facade Panel, Rectangular Shape, Tube Form, Slanted Column, Tall Circular Column, Segmented Tube Form, Freeform Rectangular Shape, Complex Form, and Spiral Curve.

5.2. Biophilic Space

The survey of architecture in the livable city of Melbourne CBD revealed spaces integrating four nature-related characteristics: connect to nature, indirect experience of nature, geographical, ecological, connection to place, and transitional space.

Although the majority of the recorded viewpoints did not exhibit the characteristic of connecting to nature (n = 9, 75.00%), 3 viewpoints demonstrated this feature. These 3 images showed the connection to nature spaces with as many as 13 (8.30%), 14 (8.30%), and 17 (8.30%) distinct points. (

Table 8. The Result of Connect to Nature Analysis.

Connect to Nature	Counts (n)	% of Total	Cumulative %
0	9.00	75.00%	75.00%
13	1.00	8.30%	83.30%
14	1.00	8.30%	91.70%
17	1.00	8.30%	100.00%

).

More than half of the recorded images exhibited the space characteristic of indirect experience of nature (n = 7, 58.30%). Among the 7 pictures showing the indirect experience of nature space, 6 (50.00%) displayed this characteristic at only one point each, while 1 image (8.30%) showed a viewpoint with as many as 11 points (

Table 9. The Result of the Indirect Experience of Nature Analysis.

Indirect Experience of Nature	Counts (n)	% of Total	Cumulative %
0	5.00	41.70%	41.70%
1	6.00	50.00%	91.70%
11	1.00	8.30%	100.00%

).

Although spaces conveying a sense of connection to place were observed, more than three-quarters of the images did not exhibit this characteristic. Of the 12 pictures analyzed, 3 depicted spaces conveying a sense of connection to the background of the place (25.00%), with each image showing this characteristic at only one point (

Table 10. The Result of Connection to Place Analysis.

Connection to Place	Counts (n)	% of Total	Cumulative %
0	9.00	75.00%	75.00%
1	3.00	25.00%	100.00%

).

Transitional space was observed to the same extent as spaces conveying a sense of connection to place. Of the 12 selected images, only 3 (25.00%) contained transitional spaces. Moreover, each of these images exhibited this characteristic at only one point (

Table 11. The Result of Transitional Space Analysis.

Transitional Space	Counts (n)	% of Total	Cumulative %
0	9.00	75.00%	75.00%
1	3.00	25.00%	100.00%

).

Among the four types of spaces identified in Biophilic architecture, connecting to nature was the most frequently observed characteristic, with three viewpoints exhibiting this feature at as many as 13, 14, and 17 points. Indirect experience of nature was the second most frequently observed space characteristic, with one viewpoint exhibiting this feature at 11 points. Spaces conveying a sense of connection to place and transitional spaces appeared only once across three viewpoints (

Table 12. Frequency of Biophilic Space Features.

Biophilic Space Features	Mean	SD	Min	Max
Connect to Nature	0.00	0.00	0.00	17.00
Indirect Experience of Nature	1.00	1.00	0.00	11.00
Connection to Place	0.00	0.00	0.00	1.00
Transitional Space	0.00	0.00	0.00	1.00

).

In terms of space, the study on Biophilic Architecture in the CBD of the Livable City of Melbourne revealed additional characteristics identified through independent coding. These included Rectangular Opening, Open Space Beneath Building, Connected Interior Open Space, and Flowing Space From Exterior to Interior.

5.3. Biophilic Material

The survey of architecture in the livable city of Melbourne CBD revealed that only three Biophilic material characteristics were consistently observed across the documented buildings, namely clay or concrete, connected with nature, and natural material.

Among the 12 documented images, materials resembling clay or concrete were observed in 8. Of these 8 images, 5 (41.70%) displayed this material at two points each, while the remaining 3 (25.00%) showed it at only one point. The other 4 images (33.30%) did not exhibit any materials resembling clay or concrete (

Table 13. The Result of Clay or Concrete Analysis.

Clay or Concrete	Counts (n)	% of Total	Cumulative %
0	4.00	33.30%	33.30%
1	3.00	25.00%	58.30%
2	5.00	41.70%	100.00%

).

Out of the 12 documented images, materials conveying a sense of connection with nature were observed in 3 images (25.00%), with each image showing this characteristic at only one point. The remaining images did not exhibit this material characteristic (

Table 14. The Result of Connect with Nature Analysis.

Connect with Nature	Counts (n)	% of Total	Cumulative %
0	9.00	75.00%	75.00%
1	3.00	25.00%	100.00%

).

Within the 12 images documented in this study, materials classified as natural were observed in 4 images (33.30%). Each of these images displayed the characteristic at one or more points, while the remaining 8 images (66.70%) did not exhibit any natural material (

Table 15. The Result of Natural Material Analysis.

Natural Material	Counts (n)	% of Total	Cumulative %
0	8.00	66.70%	66.70%
1	4.00	33.30%	100.00%

).

The most frequently observed Biophilic material characteristic in the Biophilic architecture of Melbourne was materials resembling clay or concrete, followed by natural materials, and connecting with nature. However, each characteristic was observed at only one to two points per viewpoint (

Table 16. Frequency of Biophilic Material Features.

Biophilic Material Features	Mean	SD	Min	Max
Clay or Concrete	1.000	2.00	0	2
Connect with Nature	0.000	0.00	0	1
Natural Material	0.000	0.00	0	1

).

In terms of material, independent coding indicated additional features beyond those encompassed by the framework. These included Industrial Finish, Glass, Frosted Glass, Aluminum, and Painted Concrete.

5.4. Biophilic Color

In this study, concerning the color characteristics of the Biophilic architecture in Melbourne CBD, only natural color was consistently observed across the documented buildings.

Almost all of the recorded images exhibited characteristics of natural color. However, this characteristic was observed at only one to two points per image in 8 (66.60%) of the 11 images that exhibited natural color. Interestingly, 2 images (16.70%) exhibited natural color as many as 14 times each. Additionally, 1 image (8.30%) exhibited natural color at the highest frequency, showing this characteristic at 18 points (

Table 17. The Result of Natural Color Analysis.

Natural Color	Counts (n)	% of Total	Cumulative %
0	1.00	8.30%	8.30%
1	4.00	33.30%	41.70%
2	4.00	33.30%	75.00%
14	2.00	16.70%	91.70%
18	1.00	8.30%	100.00%

).

Therefore, regarding the color characteristics of Biophilic architecture in the livable city of Melbourne, natural color can be concluded as the most prominent and frequently observed feature. In the image where this characteristic was most frequently observed, natural color appeared at as many as 18 points (

Table 18. Frequency of Biophilic Color Features.

Biophilic Color Features	Mean	SD	Min	Max
Natural Color	2.000	1.00	0	18

).

Regarding color, the independent coding conducted in this study on Biophilic Architecture in the CBD of the Livable City of Melbourne revealed more specific color characteristics. The observed colors included Red, Orange, Pink, Brown, Green, Blue, Gray, and White.

5.5. Biophilic Light

The light characteristics observed in Melbourne’s Biophilic architecture included light and shadow, lighting refuge, filtered and diffused light, and reflected light.

The characteristic of distinct contrasts between light and shadow was identified in half of the recorded views for this study. Specifically, 5 images (41.70%) displayed this attribute at one point, while 1 image (8.30%) exhibited it at two points of hard light and shadow (

Table 19. The Result of Light and Shadow Analysis.

Light and Shadow	Counts (n)	% of Total	Cumulative %
0	6.00	50.00%	50.00%
1	5.00	41.70%	91.70%
2	1.00	8.30%	100.00%

).

Of the 12 selected views, only 3 (25.00%) exhibited lighting refuge, suggesting that this quality was relatively uncommon in the documented cases. Among these, 2 views (16.70%) displayed this characteristic at a single point, while 1 view (8.30%) revealed it at two distinct points (

Table 20. The Result of Lighting Refuge Analysis.

Lighting Refuge	Counts (n)	% of Total	Cumulative %
0	9.00	75.00%	75.00%
1	2.00	16.70%	91.70%
2	1.00	8.30%	100.00%

).

The characteristic of filtered and diffused light was observed in half of the selected views, while the other half showed no occurrence of this attribute. In the 6 views (50.00%) where it was present, the feature appeared consistently at a single point within each view (

Table 21. The Result of Filtered and Diffused Light Analysis.

Filtered and Diffused Light	Counts (n)	% of Total	Cumulative %
0	6.00	50.00%	50.00%
1	6.00	50.00%	100.00%

).

The characteristic of reflected light was identified in 5 of the 12 analyzed images, accounting for 41.7% of the dataset. In each of these cases, the attribute was recorded only once per image, indicating its relatively limited presence compared to other light-related features (

Table 22. The Result of Reflected Light Analysis.

Reflected Light	Counts (n)	% of Total	Cumulative %
0	7.00	58.30%	58.30%
1	5.00	41.70%	100.00%

).

The most frequently observed light-related characteristic in Melbourne’s Biophilic architecture was light and shadow, followed by filtered and diffused light, reflected light, and lighting refuge. However, these characteristics were typically identified at only one to two points per viewpoint (

Table 23. Frequency of Biophilic Light Features.

Biophilic Light Features	Mean	SD	Min	Max
Light and Shadow	0.500	0.00	0	2
Lighting Refuge	0.000	0.00	0	2
Filtered and Diffused Light	0.500	0.00	0	1
Reflected Light	0.000	0.00	0	1

).

In terms of lighting, no additional characteristics beyond the framework were identified. The observed features included direct sunlight on sunshade panels and sunlight-blocking components.

6. Discussion

This study investigated the extent of biophilic architecture within Melbourne’s Central Business District (CBD), which is internationally acknowledged for its urban livability. Out of 6375 surveyed properties, only four buildings met the criteria for biophilic architecture, accounting for just 0.06% of the total building stock. The presence of biophilic architecture in Melbourne’s Central Business District (CBD) was found to be relatively low. This suggests that, although biophilic design may contribute to urban livability [23,24,25,26], it might not play a significant role in the context of Melbourne. A possible factor contributing to the findings that contrast previous research is that Melbourne is not deficient in green spaces or natural features. The city’s residents can readily access green areas around the Central Business District (CBD) [64]. Nevertheless, the aforementioned hypothesis still needs to be empirically tested. Furthermore, future studies should explore the architectural factors contributing to Melbourne’s livability.

The coding results revealed the following Biophilic features across architectural aspects. Form included Rectangular Form, Box Shape, Rectangular Facade Panel, Rectangular Shape, Tube Form, Slanted Column, Tall Circular Column, Segmented Tube Form, Freeform Rectangular Shape, Complex Form, and Spiral Curve. Space featured a Rectangular Opening, an Open Space Beneath the Building, a Connected Interior Open Space, and a Flowing Space From Exterior to Interior. Material encompassed Industrial Finish, Glass, Frosted Glass, Aluminum, and Painted Concrete. Colors comprised Red, Orange, Pink, Brown, Green, Blue, Gray, and White. Light was represented by direct sunlight on the sunshade panel and the sunlight-blocking components.

The results were identified using a framework developed from the literature review. The study revealed that among the characteristics of Biophilic architecture in Melbourne, biophilic design was the most frequently observed form, while other forms, such as biomorphic design, natural form, and natural pattern, appeared only sporadically. The results indicate that biophilic architectural forms in Melbourne display limited diversity. This can be attributed to the fact that most buildings within the city’s Central Business District (CBD) are high-rise or commercial structures governed by the Heritage Overlay and the Building Code of Australia [65,66]. Consequently, the emergence of new or innovative forms is highly constrained or often visually imperceptible within the grid-based urban fabric and streetscape.

In terms of space, connection to nature was the predominant feature, followed by indirect experience of nature, whereas connection to place and transitional spaces were rarely observed. This finding aligns with the works of Kellert (2008) and Beatley (2011), who emphasized that the connection to nature represents a highly adaptable and pragmatic form of biophilic design, particularly within dense urban contexts [50,67].

Regarding materials, clay or concrete-like materials were most common, followed by natural materials and features emphasizing connection with nature, although each appeared at only one to two points per viewpoint. This finding is consistent with multiple data sources and previous studies indicating that concrete holds a significant and dominant role in construction materials [68,69,70]. However, this observation may have limited relevance in identifying the distinctive characteristics of biophilic design.

Natural color emerged as the most prominent color characteristic, observed at up to eighteen points in some images. Given that much of Melbourne’s CBD consists of heritage buildings, prior research examining façade color composition indicates a close relationship between color use and heritage conservation. The prevailing color schemes typically reflect natural hues and earthy tones [71,72].

Light and shadow were the most frequently noted lighting attributes, followed by filtered and diffused light, reflected light, and lighting refuge, typically appearing only at one to two points per viewpoint. Due to Australia’s vigorous solar intensity, coupled with the compact grid structure of Melbourne’s CBD, characterized by two-lane streets and closely positioned buildings, the city’s morphology substantially influences urban microclimates, particularly in terms of the distribution of light and shadow across the streetscape [73,74].

7. Limitation

Despite offering valuable insights into the relationship between biophilic architecture and urban livability, this study has several limitations that should be acknowledged.

First, Melbourne may not serve as an ideal case for investigating biophilic architecture, as the prevalence of such buildings within its Central Business District (CBD) is extremely limited. Although Melbourne is consistently recognized as one of the world’s most livable cities, biophilic architectural examples account for only a negligible portion of its building stock, thereby constraining the generalizability of the findings.

Second, the study context presents a unique yet restrictive urban fabric. The CBD of Melbourne is characterized by its heritage-protected status and stringent building regulations under the Heritage Overlay and the Building Code of Australia. While these constraints make Melbourne an intriguing case for examining biophilic design within a historically preserved setting, they simultaneously limit opportunities for architectural innovation or the emergence of distinctly biophilic forms.

Third, the analytical framework employed in this research was developed from existing literature. Although this framework provides conceptual rigor and consistency, it may also impose certain definitional boundaries that restrict the identification of novel or context-specific manifestations of biophilic design.

Future research should therefore explore biophilic architecture across diverse urban and climatic contexts, incorporate comparative analyses, and consider adaptive or evolving frameworks that can capture broader interpretations of biophilic principles.

8. Conclusions

This study examined the presence and characteristics of biophilic architecture within Melbourne’s Central Business District (CBD), a globally recognized livable city. The findings reveal that biophilic architecture represents only 0.06% of the total building stock, suggesting that, while biophilic design can enhance urban livability, its influence in Melbourne remains limited. The analysis identified key architectural attributes related to form, space, material, color, and light, with the most prevalent features being connection to nature, natural color tones, and the modulation of light and shadow influenced by the city’s grid morphology and intense solar conditions. The dominance of concrete and heritage-protected buildings constrains the diversity of biophilic forms. Although Melbourne may not serve as an ideal case for studying biophilic architecture due to its scarcity of examples, its regulated and historically rich context provides valuable insight into how urban and architectural constraints shape biophilic expression. Furthermore, the use of a literature-based coding framework offers conceptual clarity but may limit the discovery of emergent or context-specific design characteristics. Future research should therefore extend beyond Melbourne to compare diverse urban settings and explore adaptive frameworks that capture evolving interpretations of biophilic design.