Research on the Multi-Sensory Experience Design of Interior Spaces from the Perspective of Spatial Perception: A Case Study of Suzhou Coffee Roasting Factory

Abstract

With globalization and the transformation of socio-cultural structures, the focus of spatial design has shifted from functionality to perceptual experience and atmospheric creation. This study draws on the spatial perception theory and the phenomenology of perception to examine how sensory subjects perceive and respond to the physical attributes of space. It explores key elements that shape spatial experiences, including lighting, color, spatial form, sound, material, and scent, all of which contribute to the construction of emotional ambiance and the perceptual character of interior environments. Based on this foundation, this study proposes multi-sensory design strategies for interior spaces, including the following: (1) visual perception: modifying color and lighting to establish emotional ambiance and enhance spatial depth; (2) auditory perception: crafting soundscapes that deepen immersion; (3) tactile perception: designing both direct and indirect tactile experiences; and (4) olfactory and gustatory perception: incorporating scent design to evoke memory and forge emotional connections. To demonstrate the practical potential of these strategies, this study presents a conceptual design case of a coffee roasting factory in Suzhou. The design integrates visual, auditory, tactile, olfactory, and gustatory elements to enhance users’ overall spatial perception through multi-sensory coordination. This study ultimately seeks to provide theoretical insights into practical design strategies, highlighting the importance of perceptual experience in improving spatial quality and guiding future interior design practice.

1. Introduction

As socio-economic structures continue to evolve and as cultural diversity deepens, the demands for interior space design have become increasingly intricate and multifaceted. In recent decades, the research on interior space design has predominantly focused on functional layouts and spatial morphology, with relatively limited attention given to the interaction between individuals and the spatial environment as well as the creation of spaces that provide profound experiential value [1,2]. Traditional spatial design has typically emphasized functionality and esthetic value. However, with the growing recognition of the significance of sensory experiences, scholars have increasingly focused on how space design can address multi-sensory needs to enhance the overall perceptual experience of a space.

Research across various disciplines indicates that spatial perception is inherently linked to the body [3,4,5,6,7]. The body possesses agency in the perceptual process; it is not merely a passive recipient of sensory stimuli but an active participant that engages with the environment and constructs self-awareness [8]. In this process, sensory perception regulates the relationship between the body, the mind, cognition, and the environment [9]. Human social interactions and self-perception are crucial for the integration of multi-sensory information. Gibson et al. argued that social interaction is not solely dependent on verbal communication but is profoundly influenced by multi-sensory and bodily perceptions [10]. This multi-sensory integration not only shapes interpersonal interactions but also directly influences an individual’s perception and cognition of their environment. Sensory information received from the surrounding environment has a significant impact on our perceptions and behaviors [11]. Visual perception serves as a fundamental sensory input for spatial perception [1]; however, spatial experience transcends visual perception, encompassing a multi-dimensional and integrative process of perception. The comprehensive stimulation of auditory, tactile, and olfactory senses compensates for the limitations of visual perception, collectively shaping a profound multi-sensory experience that seamlessly integrates the individual with their environment [12].

In recent years, scholars have delved deeper into the exploration of multi-sensory experiences within a space, with particular emphasis on the creation of spatial ambiance. Atmosphere is the subjective reflection arising from the multi-sensory integration of various perceivable elements within a space [13]. Dai et al. (2021) argued that multi-sensory spatial perception plays a crucial role in shaping the emotional ambiance of public spaces [14]. Within the theoretical framework of multi-sensory anthropology, the senses are not merely manifestations of physiological function; they are deeply embedded in social norms, cultural expressions, and interpersonal interactions [15]. Multi-sensory experiences not only enhance the depth of perception but also directly shape how individuals interact with others, perceive space, and even form their identity and cultural affiliation [15]. Within this theoretical framework, a space is regarded as a complex perceptual system: not merely a physical environment that accommodates objects and activities but also a setting that stimulates emotional and cognitive responses. Numerous scholars have pointed out that sensory stimuli in spatial design, by modulating the perceptual process, not only shape emotional responses but also profoundly influence the formation and evolution of behavioral patterns [16]. For example, Tony Hiss in The Experience of Place emphasized that the atmosphere, emotional responses, and behavioral reactions of a space are all the result of the interplay of multiple sensory influences [17]. He notes that the combined effects of factors such as lighting, temperature, texture, and sound not only influence individuals’ physiological states but also evoke emotional resonance. These studies demonstrate that the atmosphere plays a critical role in shaping emotional responses; it not only influences how individuals perceive a space but also directly determines their emotional experience within it [18].

Consequently, the goal of modern interior spatial design has shifted from mere functionality to the comprehensive enhancement of sensory experiences. Designers harness the synergistic effect of multiple senses to improve spatial ambiance, thereby strengthening users’ emotional connection and sense of belonging. Research indicates that, in retail environments, the stimulation of the senses through atmospheric elements such as visual effects, sound management, material textures, and ambient scents can significantly enhance both the spatial appeal and the perceived comfort of the space [19]. The interactivity and resonance of sensory stimuli enable a design to transcend traditional esthetic and functional requirements, deepening users’ spatial experience through emotional transmission and psychological cues. The integration of sensory elements such as vision, hearing, and touch to create environments that are both emotionally profound and spatially captivating has become a central topic in contemporary interior spatial design and a key approach to enhancing the overall quality of spatial experiences.

This study aims to optimize sensory experiences in interior spaces by analyzing multi-sensory design strategies grounded in the spatial perception theory. A conceptual design of a coffee roasting factory in Suzhou is used as a case study to propose a series of methods that stimulate the visual, auditory, tactile, olfactory, and gustatory senses. Rather than being evaluated through post-occupancy measurements, the effectiveness of these strategies is discussed in terms of their theoretical coherence and integration into the design development process. Specifically, the objectives of this study are as follows:

• To explore the relevant concepts, characteristics, and the subject–object relationships of spatial perception through case study analysis;
• To analyze how different sensory design elements (such as vision, hearing, touch, smell, and taste) collaborate within a spatial design to enhance the sensory experience;
• To propose a set of practical design methods and strategies for interior spatial perception, offering both theoretical support and methodological guidance for future design practices.

The contribution of this study lies in presenting a new perspective for interior design through a multi-sensory design framework and in demonstrating the applicability of spatial perception theory through a design-driven case study.

2. Literature Review

2.1. Concepts Related to Spatial Perception

Spatial perception serves as the core theoretical framework in interior spatial design, providing both scientific foundations and philosophical perspectives for understanding the relationship between individuals and spaces. As a fundamental concept in design, a space encompasses functional, emotional, and socio-cultural significance, acting as a bridge between the material world and human experience. In The Sense of Space, Morris argued that we perceive not only the spatial relationships between ourselves and others but also the presence and properties of objects within a given space [20]. From the perspective of its intrinsic meaning, a space is not merely a geometric domain but a multidimensional entity. The Oxford English Dictionary defines space as the form of existence for material movement, consisting of length, width, and height, emphasizing its exploratory and infinite nature, and typically referring to a specific area or location [21]. Laozi, in the Tao Te Ching, stated, “By hollowing out doors and windows, a room is formed; it is the emptiness that makes it useful”, illustrating that the significance of a space lies not only in defining what is present but also in the creative potential of what is absent [22]. This perspective also offers valuable insights for interior space design, suggesting that the value of functional spaces lies not only in their physical composition but also in their ability to fulfill human activities and psychological needs.

The elements that constitute a space include points, lines, planes, volumes, light, shadow, and materials. These elements work synergistically, collectively shaping the holistic multi-sensory experience of the space [23]. Point is the most fundamental element of the space, and through its varying size and density, it imparts a sense of dynamism to the space. Points with varying densities and arrangements can create visual focal points, evoke emotional responses, and infuse the space with vitality. In Point and Line to Plane, Kandinsky highlighted the dynamic and emotional qualities of lines, demonstrating how their arrangement and combinations in a space can evoke varying visual effects [24]. Planes and volumes define and occupy a space, providing a multi-dimensional framework for interior design. Light and shadow play a crucial role in interior design, as the interaction between a space and light shapes the overall experience [25]. The interplay of natural and artificial light stimulates the visual elements within a space, and the variation in light and its expression further influences emotional responses, thereby enhancing the space’s mood and ambiance [26]. At the same time, material, as one of the most immediate perceptual elements in a space, profoundly influences the user’s experience through both tactile and visual interactions.

Perception, as a comprehensive activity involving both psychological and physiological processes, is at the core of a spatial experience. It involves the cognition of an object’s spatial properties, such as size, shape, stability, and motion, as well as the distance and orientation between the object and the observer [20]. We do not directly perceive a space but rather the spatial dimensions of the objects and individuals within it [20]. George Berkeley proposed the concept of “Esse est percipi” (to be is to be perceived), emphasizing that perception is not merely the cognition of the objective world but also a product of the interaction between the subjective self and the environment [27]. Perception progresses from sensation to perception and ultimately to cognition. Sensation, as the starting point of perception, is the “fundamental process in the formation of complex experience” [28]. Sensation refers to an immediate, fundamental, and direct experience, which is the conscious perception of the characteristics or attributes of the natural environment [29]. It is the initial reception of external information by humans through sensory modalities such as vision, hearing, and touch. Perception is the integration of these sensory inputs, which leads to a comprehensive understanding of objects [29]. Merleau-Ponty argued that the body and perception are inseparable, with the body serving as the medium through which a space is perceived [8]. Perception is not only the physical cognition but also the subjective awareness of sensations, movements, and bodily positions, representing a direct dialog between the body and the environment [8]. Sensation and perception entail an integrated, inseparable process. Cognition is the advanced stage of perception, where information acquired through the senses is processed and transformed, ultimately leading to the formation of knowledge. Herbert A. Simon, often referred to as the “father of cognitive psychology”, argued that this process is a synthesis of elements such as sensation, association, thought, memory, and language [30], which elevates the spatial experience into the understanding of culture and emotion.

2.2. Perceptual Phenomenology and Spatial Perception

Phenomenology offers a unique perspective on perception, focusing on the genuine experience of a space by humans. As a key branch of Western philosophy, phenomenology emphasizes “returning to the things themselves” [31], exploring the essential connection between perception and space, and revealing the reciprocal relationship between humans and their environment. The consciousness generated by perception interacts with the surrounding physical space, where the space not only influences our perception and psychological state but also our thoughts and consciousness shape our understanding of the space, reflecting a dialectical relationship [32]. Merleau-Ponty’s phenomenology of perception particularly focuses on the role of the body in the perceptual process, asserting that a space is formed through the integration of bodily movements and sensory perception into a holistic experience [8]. Sensory experiences and perceptual memory are intricately intertwined, with different sensory stimuli not only altering our perception of space but also shaping its emotional ambiance through unconscious emotional responses [33]. Juhani Pallasmaa further emphasized that senses and spaces are inseparable, and perception is an integrative process involving the collaboration of multiple senses [34]. Through the perception of elements such as a spatial scale, materials, and light and shadow, individuals can evoke emotional resonance within the physical space.

Phenomenology provides an effective framework for understanding the body’s response to a space, where the body is not only a medium of perception but also the subject of perception [35]. The integration of bodily movements and sensory perception transforms the spatial experience into a comprehensive process, blending dynamic and static elements [36]. Phenomenology emphasizes experiencing a space through a continuous interaction with various elements [37]. Sensory stimuli shape the perception of ambiance within a space by directly triggering emotional responses. Merleau-Ponty’s theory, further expanded in Shusterman R.’s research, posits that human perception results from the interaction between the body and objects, with tactile experiences shaping the emotional cognition of space through bodily memory [38]. Various sensory stimuli play a crucial role in spatial experiences, profoundly influencing individuals’ emotional and affective responses by modulating the perceptual process [39].

Thus, within the framework of perceptual phenomenology, a spatial experience is not merely a response of the body to external stimuli but the outcome of the complex interaction between the individual and the space. Through the synergistic effect of multiple senses, the emotional ambiance and cultural significance of a space are elevated, becoming a profound medium that reflects both individual and collective identity. Sensory experiences and perceptual memory are intricately intertwined, with different sensory stimuli not only altering our perception of space but also shaping its emotional ambiance through unconscious emotional responses [40]. In this process, a space exists not only as a physical entity but also as a vessel for emotion and culture.

2.3. Fundamental Characteristics of Spatial Perception

Spatial perception, as a product of human interaction with the environment, exhibits the following characteristics:

One key aspect of spatial perception is its relativity of scale, which emphasizes the dynamic relationship between the human body and the dimensions of space. The concept of human scale, closely tied to ergonomics, aims to optimize the interaction between users and spatial environments, thereby enhancing both individual comfort and overall spatial efficiency [41]. Historically, the human body has served as a fundamental reference point for proportion and scale in the built environment [42]. Le Corbusier’s Modulor theory, using a six-foot human figure as a reference, proposed a harmonious model of proportion between architecture and the human body, providing a universal framework for architecture and spaces [43]. In design practice, the spatial scale becomes a perceptual tool that can direct user movements, shape psychological expectations, and construct narrative sequences within a space. For instance, the Taicang Art Museum integrates the layered spatial logic of traditional Chinese gardens to create a coherent and fluid spatial rhythm (Figure 1). The corridor interior (a) modulates human-scale relationships to guide visitors gradually through an immersive sequence, while the exterior layering (b) orchestrates massing transitions that mediate between the body and the architectural form. These spatial strategies reflect the multiple layers of spatial perception theory—such as the phenomenological emphasis on embodiment and the cognitive structuring of experiences through proportions and movements. Through the intentional variation in scale, the museum not only enhances its spatial atmosphere but also strengthens users’ emotional identification with the space, fulfilling both sensory engagement and cultural resonance.

A core characteristic of spatial perception is its ambiance, which is also a key element of the perceptual experience. Peter Zumthor argued that spatial ambiance is composed of various elements, such as light, shadow, materials, and colors, forming a holistic perceptual experience [44]. The perception of ambiance is not the result of a single element but rather the interaction of various factors, relying not only on subjective human experiences but also on non-human elements such as nature, objects, and physical components of the environment [45]. For example, the Indian Brick Vault School Library uses the curved form of clay bricks, creating an organic integration with the surrounding natural environment. Sunlight filters through the windows, producing a subtle contrast with the interior material textures, thereby creating a layered and tranquil spatial ambiance. Ambiance not only reflects the emotional qualities of a space but also directly influences the psychological state of its users.

Another key characteristic of spatial perception is its embodied nature, which reflects the interactive relationship between the body and the space. The body is not merely a passive receiver of sensory stimuli but an active agent engaging with the environment [46]. Through actual activities in architectural and urban spaces, individuals are able to develop a comprehensive bodily understanding of physical spaces [14]. A space not only defines the trajectories of human actions but also presents varying perceptual effects as behaviors shifts. The Brion Family Cemetery, through variations in paths and spatial forms, conveys distinct perceptions of life and death [47], whereas the Cherry Hill House redefines spatial attributes by blurring functional boundaries, integrating human behavior into the design logic. By gaining a profound understanding of spatial behavior, designers can more effectively integrate user experience into their design process.

2.4. Factors of Spatial Perception

2.4.1. The Subject of Spatial Perception: Senses

The experience of space is primarily realized through sensory perception, with the senses acting as the medium through which spatial information is conveyed. Merleau-Ponty referred to the holistic sensory experience as the “great world”, while specific sensations are termed the “little world” [48]. Spatial perception relies on human senses, namely, the five senses—vision, hearing, touch, smell, and taste—which serve as the primary means through which humans receive and process spatial information, collectively forming a comprehensive perceptual system.

Visual perception is the process through which humans observe and interpret spatial information via the eyes. Research indicates that approximately 80% of external information is derived from visual inputs [49]. Gibson (2014), in his Ecological Theory of Vision, argued that the “visual world” is composed of the familiar and commonplace scenes encountered in our daily lives [50]. In the “visual field”, what we perceive as a square is indeed a square, and what appears as a horizontal plane is perceived as such; these observations are directly apprehended through visual perception [51]. In spatial design, the creation of visual perception is closely linked to the variations in shapes, materials, colors, and light–shadow dynamics within a space; together, these elements shape the overall spatial experience [52]. For instance, through the contrast of colors and light–dark dynamics, designers can enhance the spatial depth and emotional expressiveness of the environment.

Sound is omnipresent within a space, exerting direct and profound effects on individuals’ psychological responses. Compared to vision, auditory perception elicits faster responses and possesses an all-encompassing nature, capable of creating ambiguous intentions within a space. The immediacy and multidimensionality of sound have been extensively studied [53,54]. For instance, Marks (1975) categorized sounds in spaces according to different frequency colors, such as red, yellow, blue, and green, with each space possessing its own distinct auditory properties [55]. Variations in sound can shape diverse spatial experiences and is capable of both focusing attention and creating a sense of detachment within a space. Therefore, auditory perception within a space must consider the diversity of sound, combining natural sounds with artificial ones to create distinct spatial atmospheres and enhance the poetic quality of the space [56].

Touch is the earliest developed sense in humans and serves as the primary medium for interacting with the external world [57]. Juhani Pallasmaa, in The Seven Senses of Architecture, referred to touch as the “mother of the senses”, asserting that it is the origin of all other senses and an extension of sensory faculties such as the eyes, ears, nose, and mouth [58]. Touch enables us to simultaneously perceive both the internal and external worlds of the body [59]. Based on the agency of tactile perception, touch can be categorized into active and passive tactile perception [60]. Passive tactile perception refers to the sensory experiences of the body in a space, such as the perception of temperature, material textures, gentle breezes, and sunlight. Le Corbusier’s use of the texture and tactile qualities of concrete in the Unité d’Habitation serves as a classic embodiment of tactile perception in architectural design [61].

Olfaction and gustation are often overlooked in interior design; however, they play a distinctive role in shaping spatial experiences. Studies on olfaction and gustation have shown that they can significantly influence human emotions and memory [62]. For example, the sweet scent of candies in a candy store can evoke memories of carefree childhood moments. Although less prominent than vision and hearing, olfaction and gustation can leave a lasting impression on memory within a space. For example, in The Poetics of Space, Bachelard illustrated how the scent of a single raisin in a space can evoke an entirely different atmosphere within the realm of human imagination [63]. At times, visual elements can also be translated into gustatory experiences. For instance, C. Spence, in The Perfect Meal: The Multisensory Science of Food and Dining, discussed a study where researchers served the same flavored foods (such as desserts) on plates of different shapes. The findings revealed that participants were more likely to perceive desserts on round plates as sweeter, while those served on plates with sharp edges were described as having a more “pungent” or “bitter” taste [64]. Therefore, designers should recognize the subtle role of olfaction and gustation in spatial experiences and make use of these senses to add greater depth and emotional dimension to a space.

2.4.2. The Object of Spatial Perception: Spatial Elements

An object is something that is perceived and observed. The object of spatial perception encompasses all material elements that influence spatial experiences and atmospheres [65] or the spatial environment formed by these elements, including nature, materials, light, shadow, and colors. These elements collectively form the core of shaping the spatial ambiance. Natural elements such as light, wind, and water, along with material elements like wood, concrete, and stone, are commonly regarded as key factors influencing spatial ambiance [66].

The use of natural elements in interior design is crucial for shaping the atmosphere. Light, water, and wind, as the most common natural elements, profoundly influence the emotional ambiance of a space through their physical properties [67]. Light, particularly natural light, serves as a crucial tool for expressing the emotional tone of a space. Numerous studies on lighting in interior spaces have shown that factors such as light intensity, direction, and color temperature directly influence spatial perception, thereby affecting the emotions and behaviors of space users [68,69,70]. The interplay between light and space breathes life into material forms, enabling the emotional hues of a space to unfold [71]. Natural light is typically variable, whereas artificial light can be precisely controlled, aiding in the creation of the ideal spatial atmosphere [72]. Water, as a natural element, plays an indispensable role in shaping the spatial atmosphere through its dynamic and static changes. The mirror-like reflection, fluidity, and integration with the environment of water add depth and layers to a space. In Zen-inspired spaces, water conveys a tranquil and solemn atmosphere [73], while in commercial spaces, it evokes feelings of elegance and prestige. In addition, although wind is difficult to perceive directly, the sounds of or changes in airflow associated with it can profoundly affect spatial perception. Particularly, the interaction between wind and architectural structures can create unique spatial acoustic effects, which are well exemplified in traditional Jiangnan gardens [74]. The “Wind Sound Cave” in the Ge Garden of Yangzhou, Jiangsu Province, China, serves as a typical example, where the interaction between wind and spatial structure creates a unique acoustic landscape with a distinct atmosphere.

The selection of materials directly influences the emotional expression of a space, thereby affecting people’s perception and experience of the environment. Zumthor, in Thinking Architecture, noted that materials themselves do not inherently possess a poetic quality; it is only through the creativity and vision of the designer that the essence of materials can be revealed [75]. For example, in Zumthor’s design of the Saint Benedict Chapel, the interplay between the columns and the roof, along with the use of materials and spatial forms, conveys the concept of eternity in religion [76], creating a spatial ambiance with profound symbolic significance. Through the harmonious design of nature and materials, space can convey emotional and cultural meanings that transcend the material realm. Spanish furniture designer Patricia Urquiola incorporates various fabric materials, such as wool, linen, suede, and synthetic textiles, into her designs. Through unique weaving techniques or stitching methods, she enhances both the tactile and visual qualities of these materials. The use of such materials often amplifies the design’s appeal and comfort.

The following framework diagram illustrates the factors of spatial perception for the reader’s ease of reference (Figure 2).

2.5. Construction of Theoretical and Design Strategy

To effectively apply the theoretical perspectives outlined in Section 2.1, Section 2.2, Section 2.3 and Section 2.4 to the subsequent design strategies, the following table summarizes the correspondence between each key theoretical concept and its associated spatial design strategy (

Table 1. Mapping theoretical concepts to multi-sensory spatial design strategies. Source: author’s drawing.

Theoretical Concept	Core Idea	Corresponding Design Expression
Spatial Perception	Space is rendered experiential through bodily movements, spatial orientations, and perceptual thresholds.	Design of perceptual nodes through spatial scales, circulation paths, visual axis organization, and rhythmic transitions
Phenomenology of Perception	Space is perceived directly through the embodied experience.	Tactile qualities of materials and interface interactions; pre-reflective spatial cues (e.g., light and shadow variations and temperature differences); and slow-paced circulation and moments of pause
Five Senses Framework	Human experience of space is mediated by the interaction of the five senses.	The integration of five-sense design, sensory zoning with hierarchical organization, and the construction of cross-modal memory and emotional resonance
Affective Atmosphere Theory	Atmosphere is shaped through sensory modulation, forming an emotional field.	Design details involving the rhythm and temporal control of soundscapes, color temperature and light–dark contrast, scent diffusion and memory activation, and the emotional resonance of materials

). This mapping not only supports the practical implementation of theoretical insights but also provides a theoretical foundation and structural logic for the design methodology presented in Section 3.

This mapping bridges the gap between theory and practice, ensuring that each design strategy is grounded not only in sensory logic but also in intentional emotional expression.

In summary, although spatial perception has received increasing scholarly attention in recent years, most existing studies focus on the macro-level phenomenological analysis, emphasizing the relationship between the human body and space. Many of these discussions remain theoretical, offering abstract insights into the senses without exploring how specific sensory elements influence spatial experiences and emotional atmospheres. This has resulted in a noticeable gap regarding the practical methods and strategies for integrating sensory elements in interior design, especially in terms of how to coordinate different modalities effectively within a spatial environment. With the development of technologies such as virtual reality, augmented reality, and sensory interaction systems, new opportunities have emerged for multi-sensory interior design. However, related research and practical applications remain limited. To address this gap, this study proposes a conceptual interior design approach grounded in the spatial perception theory. It investigates how interactions between spatial subjects and environmental conditions can inform the development of multi-sensory strategies and methods. These strategies are applied in a conceptual design case for the renovation of the Suzhou Coffee Roasting Factory. Additionally, this study explores the integration of emerging technologies to enhance multi-sensory experiences, aiming to create immersive and perceptually enriched interior environments.

3. Methodology and Integrated Multi-Sensory Design Strategies

3.1. Methodology

3.1.1. Research Type and Theoretical Orientation

A case study approach was adopted, with the spatial perception theory serving as the core theoretical framework. The investigation focuses on how multi-sensory experiences can be intentionally shaped through interior design strategies, emphasizing the interaction between sensory subjects and spatial conditions that influence perception. Special attention was given to the creation of emotional atmospheres and the enhancement of experiential engagement. Instead of relying on empirical testing or user-based experimentation, the methodology follows an epistemological path rooted in design research. Knowledge was developed through critical reflection, case analysis, and theoretical synthesis. A multi-case analysis method was used to examine a selection of built environments, aiming to extract applicable spatial strategies from their multi-sensory design features. This approach aligns with the principles of Research through Design (RtD), where the act of designing itself is seen as a valid mode of inquiry.

3.1.2. Case Selection and Rationale

The selected case studies were drawn from the academic literature, professional publications, and international design awards, with a focus on projects that exhibit the significant integration of multi-sensory elements, including visual, auditory, tactile, olfactory, and even gustatory factors. The cases vary in terms of geographic type and context, yet they all emphasize on the creation of a rich atmosphere and perceptual depth. The selection criteria include the following:

• The cases are completed architectural or interior spaces of notable influence;
• The design features consciously integrate two or more sensory dimensions;
• The cases are closely related to interior spatial experience, encompassing cultural, commercial, or public spaces;
• They provide comparative value in terms of spatial strategies and perceptual design.

3.1.3. Research Framework

The research framework is illustrated in the following Figure 3.

3.2. The Construction of Visual Perception

Vision is one of the most fundamental senses in spatial experiences, playing a decisive role in the initial perception and emotional response to a space. From a phenomenological perspective, visual stimuli possess a “pre-cognitive” quality, meaning that individuals can form an immediate emotional connection with a space through elements such as light, forms, and contrast—prior to any rational or conscious evaluation [77]. Influenced by the theocratic connotations of the Renaissance, scholars have linked vision with fire and light. In Modernity and the Hegemony of Vision, Levin said that “humanity’s domination by the visual paradigm dates back to ancient Greece, where all truth and reality begin with vision, centered around the visual” [78]. These historical perspectives underscore the primacy of vision in constructing spatial meaning, a notion that persists in the contemporary design discourse. In interior spatial design, visual elements primarily include the combination of colors, light, and spatial forms while also encompassing the careful construction of scales, layouts, hierarchical structures, and their interrelationships. The thoughtful arrangement of visual elements has a profound impact on spatial perception, influencing not only the esthetic presentation of a space but also playing a crucial role in shaping its emotional atmosphere and functional experience. Light, temperature, color contrast, and the rhythm of forms can subtly modulate users’ affective states, creating calming, dynamic, or intimate atmospheres through visual–emotional associations.

We can identify several different methods for creating visual spaces while considering their role in spatial design:

• Color as a means of conveying spatial emotion and scale differentiation;
• Light and shadow as fundamental elements in creating spatial depth and a sense of mystery;
• Enriching the spatial formal language to enhance the depth of visual perception.

3.2.1. Color as a Means of Conveying Spatial Emotion and Scale Differentiation

The role of color in a space extends beyond its decorative function; it serves as a core medium for emotional transmission [71], influencing the creation of spatial ambiance and even affecting individual behavior and decision making [79]. Within the spatial perception theory, color functions as a perceptual modulator that shapes users’ emotional and physiological responses, influencing orientation, scale evaluation, and spatial embodiment. Color is often associated with the concept of “temperature”, referring to the warmth or coolness of colors—warm and cool hues or spectral wavelengths. These light waves travel through the eyes to the brain, exerting significant effects on both our physiology and psychology. In particular, Merleau-Ponty’s theory emphasizes that such responses are pre-reflective bodily experiences, suggesting that the perception of color can directly influence one’s spatial awareness and sense of presence even before analytical thought is formed. Thus, color, as a key element in spatial design, is particularly significant in its connection to emotion. In Wilson’s (1966) study, participants were shown slides in an alternating sequence, each with an equal number of red and green slides [80]. The findings revealed that red, a warm color, induced more excitement than green, a cool color [80]. A similar effect can be observed in the use of color within spatial environments. Recent studies have shown, through data model analysis, that people’s emotional responses to color are not only associated with hues or wavelengths but also are primarily influenced by the color’s saturation and brightness levels [81,82,83]. For example, in leisure spaces such as cafes and libraries, light blue and beige are often used to create a relaxed and tranquil atmosphere. This affective modulation of mood through visual cues aligns with Böhme’s theory of atmosphere, wherein light, tones, and colors act as affective agents that orchestrate an individual’s emotional and spatial immersion [84].

Color plays a crucial role in shaping the emotional atmosphere of a space, and its unique visual illusion effects have a profound impact on the perception and experience of spatial scales. Research in perceptual psychology suggests that color is not merely a physical attribute of sensory stimuli; it can also produce visual illusions of the surface size of an object [85]. It is the varying properties of color, particularly changes in brightness and saturation, that influence individuals’ perception of a space’s physical scale at the sensory level. Light or cool colors, typically with higher light reflectance [86], can visually create a sense of spatial expansion and openness. Darker and warmer tones, by increasing light absorption and reducing spatial brightness, create a sense of spatial compression and enclosure, making the space appear more cramped and narrow [52]. The distribution and combination of different colors can alter the sense of scale, width, height, and proportion in a space, thus influencing the overall spatial experience.

Moreover, the choice and combination of colors are closely linked to the social and psychological characteristics of the users [82]. In Saito M’s study, he used a factor and cluster analysis to conclude that there is a general preference for the color white in Asia, a preference influenced by environmental and cultural factors [87]. In addition, studies have shown that color preferences and emotional responses are also influenced by factors such as age, gender, and background [88]. Children tend to prefer bold, vibrant colors such as pink, yellow, green, and blue [88], while young adults are more drawn to high-end hues with low brightness and low saturation, such as gray and muted tones like those found in the Morandi palette, which convey a sense of calm and sophistication. Middle-aged individuals often favor deep, grounded tones, like brown and dark green, which exude a sense of stability. Older adults are more inclined to choose colors with low brightness and low saturation, as these colors provide both visual and psychological comfort, promoting relaxation and enhancing overall well-being. These variations in color perception and preference reflect the phenomenological concept of “lifeworld”—the idea that perception is situated in one’s lived cultural and social contexts. They also align with the user-centered approach in multi-sensory design, which emphasizes adapting sensory stimuli to the needs, habits, and emotional dispositions of different user groups [89].

In healthcare space design, color selection should prioritize warm, natural, and healing tones [90], such as light yellow, beige, green, and blue, which can effectively alleviate patients’ anxiety and stress. Therefore, the rational configuration of interior colors should not only align with the functional requirements of a space but also be precisely designed based on the physical and psychological characteristics of the user group, ensuring that the emotional communication of color meets the needs of different groups.

3.2.2. Light and Shadow as Fundamental Elements in Creating Spatial Depth and a Sense of Mystery

Light is fundamental to visual experiences, as all visual information and image presentation depend on its presence for perception to occur [91]. Light, from subtle to intense, regulates the observer’s emotions and profoundly impacts the quality of architectural experience as well as human well-being [26]. From a phenomenological perspective—particularly in Merleau-Ponty’s view—light is not merely a visual tool but a “lived phenomenon” that mediates the atmosphere between the body and space. Variations in lighting conditions allow individuals to perceive the rhythm, temporality, and emotional tone of a space, enabling them to dwell within it rather than merely observe it. The use of light in a space is typically divided into two main categories: natural light and artificial light.

Natural light, as a source derived from the sun, is not only the most basic and natural form of illumination but also plays a crucial role in spatial design. Louis Kahn once said, “The building only truly appears when sunlight strikes the wall, and it is only when the sun hits one side of the building that you realize how magnificent it is” [92]. This statement profoundly expresses the importance of natural light in a space; it not only brings a sense of life to the architecture but also influences the ambiance and emotional experience of the space.

We have identified the following three functions of natural light in a space:

• Natural light as a key element in enhancing visual focal points within a space;
• Natural light as an element that enriches spatial depth and visual experience;
• Natural light as a means of creating spatial ambiance.

The following five case studies are presented to exemplify the three previously outlined methods (

Table 2. Five case studies on the role of natural light in architectural spaces. Source: author’s drawing.

Site	Role	Explicit Description	Photos (Source: Internet)
Pantheon (the heart of Rome, Italy)	Natural light as a key element in enhancing the visual focal points within a space	The large circular opening at the top of the Pantheon serves as the sole source of natural light within the interior. The angle of light shifts in response to the sun’s movement, causing the focal point of illumination to change at different times of the day. This dynamic interaction between light and space effectively transforms the building into a functional sundial, offering a perceptual experience deeply connected to the passage of time. As light plays a pivotal role in visual focus within the space, it not only enhances the visual depth and spatial hierarchy but also amplifies the sanctity and solemnity of the Pantheon as a place of worship.
			Photo source: The image has been authorized by the author Anso Lighting Design.
Church of Our Lady of Nesvacilka (Nesvačilka-Těšany 664 54, Czech Republic)	Natural light as a key element in enhancing the visual focal points within a space	The light in the Church of Our Lady primarily enters through the side windows. The orientation and placement of these windows are carefully designed to ensure that sunlight illuminates specific areas at different times of the day, particularly the altar and religious icons. In this way, the light naturally focuses on these central religious elements, making them visually prominent and guiding the congregation’s attention towards these sacred objects. This design not only enhances the visual emphasis of the religious focal points but also strengthens the solemnity of the religious rituals, reinforcing the spiritual significance of the space.
			Photo source: The image has been used with permission from the author, Ondřej Bouška, 2024.
Zhejiang Li shui Office Headquarters (top floor of office building in Li shui, Zhejiang)	Natural light as an element that enriches spatial depths and visual experiences	In the design of the Zhejiang Li shui Office Headquarters, the courtyard’s daylighting is achieved through a rotating louvered skylight, allowing natural light to filter through and cast dappled shadows across the space. This interplay of light contrasts with the traditional architectural elements of the old arcade, establishing a dialog between the past and the future. The design not only enriches the spatial layers but also enhances the visual experience, creating a dynamic connection between historical and contemporary architectural features.
			Photo source: The image has been authorized by the author Xun Chang Design.
Chapel of Light (Ibaraki City, located on the outskirts of Osaka Castle)	Natural light as a means of creating spatial ambiance	In Tadao Ando’s design, light is not merely a functional source of illumination but a crucial element in shaping the spatial atmosphere. A horizontal cross-shaped slit is incorporated into the church’s front wall, allowing sunlight to filter through at specific times of the day. This light forms a cross-shaped pattern on the interior, symbolizing Christian faith and the arrival of divine light. The cross-shaped light serves as a symbol of sacred power, suggesting the presence and revelation of God, thus enhancing the church’s religious ambiance and the sense of ritual.
			Photo source: The image has been authorized by the author Visual China.
Louis Kahn’s Exeter Library (Exeter, New Hampshire, USA)	Natural light as a means of creating spatial ambiance	Louis Kahn’s Exeter Library uses natural light to create a unique spatial atmosphere. Skylights in the roof direct light into the central hall, fostering a bright, serene environment that blends with nature. Large windows in the reading areas allow sunlight to filter in, creating a warm ambiance, while carefully designed shading elements prevent glare. As the light changes throughout the day, the library’s atmosphere evolves, with varying sunlight angles at different times, offering distinct esthetic and emotional experiences.
			Photo source: The image has been authorized by the author Chris Peng.

). These cases include the Pantheon, the Church of the Suffering Virgin, the Lishui Office Headquarters in Zhejiang, the Church of Light, and Louis Kahn’s Exeter Library in the USA. Each of these architectural works serves as a representative example of how natural light contributes to the shaping of spatial perception and experiential qualities.

Natural light is not only a crucial lighting element in space but also influences the formation of spatial depth, ambiance, and visual focal points through its unique qualities. From ancient Roman architecture to modern interior design, natural light, as a core element of spatial design, brings rich emotional expression and visual effects to a space through its flow, refraction, and reflection. Therefore, the thoughtful integration of natural light in a space not only enhances the visual quality of the space but also effectively shapes its emotional atmosphere, imbuing both architecture and interior spaces with greater vitality and expressiveness.

With the ongoing advancement of technology and the instability of natural light, the use of artificial lighting has become increasingly widespread in modern spatial design, commonly referred to as lighting design. Artificial lighting not only effectively supplements natural light but also imbues a space with a unique ambiance and visual experience [26]. Lighting design—encompassing factors such as light intensity, light source positioning, color temperature, and lighting techniques—plays a crucial role in shaping the spatial ambiance [93]. Based on varying light intensities, artificial lighting can be classified into two main categories: high-intensity lighting and low-intensity lighting. High-intensity lighting quickly captures attention and is commonly used in spaces such as theaters and exhibition areas where focus needs to be directed. For example, the still from the performance Only Green demonstrates how a concentrated spotlight disrupts the surrounding darkness to guide attention and heighten spatial tension—an effective application of visual dominance in sensory design (Figure 4a). In contrast, low-intensity lighting offers a softer feel and is ideal for spaces such as homes and art galleries, where a warm and tranquil atmosphere is desired. The color temperature of light influences the emotional experience of a space [94]. Cool light (low color temperature) often evokes a sense of calm and coolness, while warm light (high color temperature) creates feelings of warmth and relaxation. With the increasing demand for immersive spatial experiences, recent lighting design has integrated technology, giving rise to a series of interactive light and shadow immersive environments. These innovative spatial experiences go beyond static art displays, actively engaging the audience in the creative process of light and shadow interaction. For example, the Suzhou Life and Color Museum employs voice-activated light projection to transform static environments into dynamic landscapes. This integration of multi-sensory stimuli—visual, auditory, and spatial—reflects the principles of emotional resonance and embodied spatial perception discussed earlier (Figure 4b).

3.2.3. Enriching the Spatial Formal Language to Enhance the Depth of Visual Perception

The use of spatial formal language includes the treatment of individual spatial forms as well as the composition of multiple spatial forms. In real life, buildings composed of a single space are rare; most architectural spaces are typically made up of multiple interconnected spaces [23]. Therefore, we explore how the expression of spatial forms in multi-space configurations can alter people’s emotional experiences through their impact on visual perception. The design of contrast and variation, penetration and layering, and sequence and rhythm influence the emotional atmosphere of a space through the intentional use of spatial formal language.

Spatial contrast and variation refer to the perceptible differences between adjacent spaces, which are typically reflected in variations in height, openness, and enclosure; changes in spatial form; and spatial orientation. When an individual moves from one space to another, and the two spaces exhibit distinct differences—whether in size, volume, or openness—it evokes corresponding emotional changes. For instance, in the Hagia Sophia, a low, narrow vestibule precedes the lofty and spacious hall. The strong spatial contrast between the vestibule and the hall triggers a profound emotional shift as one moves through the threshold. This phenomenon is a direct reflection of how spatial contrast and variation influence emotional and psychological states.

Spatial permeability and depth refer to the intentional connection of different spaces without fully relying on physical walls for separation, thereby enhancing the sense of spatial layering. In his definition of interior rooms, Wright utilized multiple boundaries and blurred spatial layers, enabling the overlap and interpenetration of different spaces [95]. Through this design strategy, the flow between spaces is encouraged, enhancing the perception of continuity and visual complexity. Spatial permeability breaks down strict spatial boundaries, altering the perception of boundaries and scale and allowing participants to discover and experience different layers within a continuously flowing space.

Spatial sequences and rhythms—the organization of spatial sequences—play a crucial role in guiding the flow of people. The design of spatial sequences typically depends on the arrangement of pedestrian circulation paths and should incorporate a sense of rhythm, including the alternation of highs and lows, emphasis and restraint, and moments of calm and climax. In a complete spatial sequence, the climax serves as the emotional high point of the spatial experience. By utilizing spatial contrast or the relationship between spatial contraction and expansion, the climax space can be emphasized. For example, in a carefully designed spatial sequence, a compressed or enclosed space is often followed by an open or expansive one. These variations in space ultimately lead to the “climax” of the spatial experience. This spatial organization is akin to a narrative structure, where the compression and expansion of space create emotional fluctuations through contrast.

3.3. Designing Auditory Perception (Carefully Crafted Soundscapes to Enhance Immersion)

We have outlined four methods for using sound in spatial design:

• Soundscape design;
• Temporal control of sound;
• Contextual guidance through sound;
• Immersive sound interaction experience.

3.3.1. Soundscape Design

Human conscious shaping of the surrounding environment must include the sonic environment, as the sonic environment shapes the individual [96]. The construction of auditory perception within a space is often achieved through the design of ambient sounds in the environment [97]. Many studies have shown that sound can suggest the identity and function of a space [98,99]. Different sonic atmospheres not only shape the emotional ambiance of a space but also evoke emotional shifts in users, triggering relatively strong emotional reactions [100] and thereby deepening their perception and experience of the space. For example, in amusement parks, cheerful music conveys a sense of relaxation and joy; in bars, energetic music stimulates vitality and a lively atmosphere; and in commemorative museums, solemn background music enhances the dignified and reverent ambiance of the space. These soundscapes provide users with an emotional connection to the space, thereby influencing their spatial perception. The design of soundscapes can be divided into the creation of natural sounds and artificial sounds [101], with each playing a unique role within the space.

Regarding the creation of natural sounds, natural sound perception in a space arises from the interaction between acoustic phenomena and the environment, forming a key aspect of multi-sensory experience. According to the spatial perception theory, environmental sounds act as contextual cues that support cognitive orientation and emotional resonance. A typical example is the Music Chapel near Chengde, Beijing—constructed entirely of concrete and nestled in a valley—where materials, enclosures, and natural acoustics combine to create a resonant atmosphere that enhances sensory immersion (Figure 5a). Another example is the Echo Wall at the Temple of Heaven in Beijing, which utilizes the reflection of sound waves to create an interactive auditory experience. This interaction between the body, sound, and architectural geometry aligns with phenomenological principles, where perception is shaped through direct sensory engagement with a space. Regarding the creation of artificial sounds, which are generated through sound equipment or digital technology, they create specific spatial atmospheres and are particularly common in museums or exhibition spaces. For example, in the vestibule of the September 18th Historical Museum, the intensified soundscape of war, combined with dynamic digital projections, immerses visitors in the emotional tone of historical memory (Figure 5b). This sensorial orchestration of sound and image exemplifies the integration of auditory design into emotional space construction, further validating the multi-sensory design framework discussed in earlier sections.

3.3.2. Temporal Control of Sound

Temporal control of sound plays a crucial role in spatial design, particularly in guiding the spatial ambiance and influencing users’ emotional responses. The duration of sound, the timing of its onset and termination, and even its interruption can have a profound impact on the perception of a space [102]. Designers should carefully plan the timing of sound based on the spatial layout, functional requirements, and the emotional context of a space. According to phenomenological theories, especially those concerning temporality, time is not just measured chronologically but is felt bodily—lived time [103]. In this sense, the pacing of auditory elements influences how users feel duration and anticipate progression, turning the space into a dynamic, emotionally resonant experience. For example, in exhibition spaces, designers can select appropriate background music, aligning it with the content of the exhibits and the atmosphere of the display. By controlling pitch, rhythm, and volume, they can create a specific emotional ambiance. The rhythm of music can be coordinated with the undulations and layering of the space, harmonizing the sound with the spatial design. This creates a guided “sound flow” within the space. Through the precise control of sound timing, the audience can subtly perceive the sequence of the visit and the climax of the space.

3.3.3. Contextual Guidance Through Sound

Sound is not merely an accessory element of space; it also plays a powerful role in guiding the context. Different sounds can evoke visual associations and emotional responses in individuals [100]. For example, when hearing the sound of burning, people naturally associate it with the image of flames, and their emotions become heightened; similarly, the sound of falling snowflakes often evokes images of winter, inducing a feeling of coldness. The contextual guiding effect of sound enhances the emotional experience of the space, complementing its visual effects.

Designers can guide users’ emotions through the integration of sound and spatial context. In recent years, numerous sound installation artworks have emerged, incorporating sound-triggering mechanisms within specific spaces. When the audience enters a designated area, sound is immediately activated, thereby enhancing participation and immersion. For example, Zimoun exhibited a Mechanical Sound Sculpture at the NYU Art Gallery, Abu Dhabi, in 2019. The piece consists of suspended black rods connected to motors, generating periodic vibrations that trigger collisions or friction between objects, thus creating a unique soundscape. The artwork blurs the boundary between the audience and the piece itself, enhancing both immersion and interactivity.

3.3.4. Immersive Sound Interaction Experience

With the advancement of digital technology, immersive sound interaction experiences have become an innovative trend in contemporary spatial designs, such as video–audio games within spaces [104]. By combining sound with digital media technology, the audience can experience an immersive interactive effect, as if placed in a virtual world of sound and light. Immersive sound interaction not only makes the spatial experience more multi-sensory but also enhances the audience’s sense of participation and interactivity [105]. Immersive sound interaction can be categorized into two types: interaction between an individual and a space and interaction between an individual and an installation. In this context, sound interaction can be initiated by the space or installation, or it can involve the audience responding to sound, which in turn triggers feedback from the space or installation. Immersive sound interaction experiences have developed rapidly in recent years. Many art installations and experiential spaces (such as museums or exhibitions) utilize spatial audio to design soundscapes, allowing visitors to move freely within the space, with the sound location changing accordingly. Binaural stereophonic sound delivered through headphones can simulate auditory experiences in real-world environments, often used in applications such as meditation, relaxation, and virtual tourism. Virtual reality (VR) sound platforms like Oculus (Meta Platforms, Inc., Menlo Park, CA, USA) and HTC Vive (HTC Corporation, New Taipei City, Taiwan) incorporate VR games and experiences that integrate spatial audio technology to help users perceive the direction, distance, and origin of sounds within an environment.

3.4. The Application of Tactile Perception

The application of tactile perception in spatial design is becoming increasingly important, serving as a crucial dimension in creating rich spatial experiences. In his book The Eyes of the Skin: Architecture and the Senses, J. Pallasmaa noted that humans perceive the textures, patterns, temperatures, and forms of objects through their skin [34], thereby sensing the atmosphere and emotions of a space. In Touch: The Feeling of Emotion and Technology, M. Paterson explored two aspects of tactile perception: the “direct” and the “metaphorical”. Tactile perception is not limited to the immediate physical touch; it also carries a metaphorical emotional meaning, capable of evoking psychological and emotional responses through an indirect tactile design [106]. Furthermore, in multi-sensory design, tactile input often works in tandem with lighting, sound, and scent to reinforce emotional associations and sensory memory. For example, smooth surfaces paired with soft lighting may evoke calmness and intimacy, while rough, irregular materials combined with low-frequency sound may provoke alertness or tension. This cross-modal interaction demonstrates that touch is never isolated—it is deeply interwoven with other sensory systems—forming a holistic spatial experience.

We have summarized two approaches for incorporating tactile perception in spatial design:

• Creation of direct tactile perception;
• Creation of indirect tactile perception.

3.4.1. Creation of Direct Tactile Perception

Direct tactile perception, through the body’s contact with surfaces, provides one of the most immediate and intuitive ways to experience a space. In the spatial perception theory, tactile stimuli link material qualities to emotional memory, connecting physical spaces with human emotions. A powerful example can be found at the National September 11 Memorial & Museum, where the names of 2983 victims are engraved around the memorial pool. Visitors often touch these names, engaging in a tactile ritual of remembrance. This act transforms the material surface into a medium of emotional transmission, highlighting the expressive potential of tactile design (Figure 6). In interior design, materials and textures serve as core mediators of tactile perception. Natural materials such as wood, stone, and clay convey warmth and authenticity, while metal and glass evoke a sense of modernity and coolness. By carefully selecting materials, designers shape the emotional tone of a space. Modern techniques, such as biomimetic additive manufacturing, have made material textures more diverse [107]. As illustrated in Figure 7, concrete surfaces can replicate bamboo patterns (a), wood grains (b), and rammed earth textures (c), offering familiar tactile sensations through innovative fabrication. These techniques bridge tradition and innovation, enhancing sensory engagement within the spatial experience.

3.4.2. Creation of Indirect Tactile Perception

Indirect tactile perception refers to the imagined sense of touch triggered by visual observation. According to the spatial perception theory, materials, textures, and lighting can evoke tactile impressions without physical contact. At Therme Vals in Switzerland, Peter Zumthor used a local stone to shape a sensory-rich environment. Although visitors may not touch every surface, visual contrasts—such as cool stone and warm thermal water—allow them to feel material differences emotionally and mentally (Figure 8). This highlights how visual cues can simulate touch and deepen a spatial experience. This form of tactile engagement relies more on visual interpretation than on physical contact. It demonstrates how materials and environmental conditions can evoke tactile imagination and support a richer spatial experience.

3.5. Integration of Olfactory and Gustatory Perception (Experiencing Space Through Scent)

Olfaction and gustation play a crucial role in the experience of spatial ambiance. Both share a common perceptual mechanism, triggering the brain’s perception and memory storage through scent. Many studies indicate that scent, beyond being a physical olfactory phenomenon, carries emotional and social significance, evoking emotional associations with specific people, places, or memories [108], and can even trigger intense emotional responses unconsciously [58]. Thus, the design of spatial scent is not only about esthetics but also enhances the immersive experience by engaging people’s senses and emotions. The following sections focuses on how the selection and design of scent can create emotionally rich and memorable spaces.

We have outlined two methods of using scent in spatial design:

• The selection of scent and the creation of emotions;
• The creation of memorable scent spaces.

3.5.1. The Selection of Scent and the Creation of Emotions

The choice of scent directly shapes the atmosphere of a space. Studies have shown that pleasant environmental scents can effectively enhance our mood and improve our overall well-being [109,110]. For example, fresh and subtle scents often evoke feelings of comfort and pleasure, enhancing the overall comfort in a space. In office environments or commercial spaces, delicate fragrances help alleviate stress and enhance the experience of work or shopping. In stores of renowned brands, designers use strategic scent installations to create unique brand fragrances, allowing customers to form brand associations through their interaction with the space, thereby enhancing consumer experience and brand identity [111]. The selection of scent in dining spaces is particularly important. For example, an Italian restaurant might choose scents of freshly baked bread, herbs, and olive oil to create a Mediterranean atmosphere, complementing its menu and decor style. Effective scent design aligns with the function and identity of a space and works in harmony with visual and auditory elements to create a unified sensory experience. In Zumthor’s Klaus Brothers Chapel, the scent of burning pinewood evokes a sense of serenity, supporting meditation and emotional reflection. Similarly, in the “Moonlit Breeze Pavilion” at Suzhou’s Wangshi Garden, the natural scent of blooming lotus flowers enhances relaxation and strengthens the emotional bond between visitors and the space (Figure 9).

At the same time, scent design should also take into account the health and comfort of the users. Aromatic candles have become increasingly popular worldwide in recent years [112], becoming an essential part of many people’s daily lives. Studies have shown that common aromatherapy scents, such as lavender, have a significant positive impact on the human body, typically reducing stress, improving sleep quality, and even accelerating recovery from illness [113]. However, some individuals may be allergic or have adverse reactions to certain scents. Therefore, when selecting fragrances, it is important to avoid those that are overly stimulating or likely to trigger allergic reactions.

With the rapid development of digital technology, digital taste and olfactory technologies have been increasingly applied in augmented reality (AR) and virtual reality (VR) devices. Erika Kerruish’s research explored two digital devices, Vocktail (Keio-NUS CUTE Center, Singapore) and Season Traveller (Kao Corporation, Tokyo, Japan), which integrate taste and olfaction, revealing how digital technology expands sensory experiences and reshapes traditional perceptual habits [114]. The former enhances the sensory experience of drinking water and air by electrically stimulating taste buds and manipulating color and scent; the latter enhances the immersion in VR games through sensory elements such as wind, scent, and temperature [114]. The study reexamines multi-sensory technologies from cultural and perceptual perspectives, proposing a reconstruction of sensory stimuli in the digital world.

3.5.2. The Creation of Memorable Scent Spaces

Scent is closely related to memory. The Proustian effect suggests that scent can evoke specific memories, instantly transporting individuals back to past moments [115]. For example, a specific home fragrance may evoke a sense of familiarity and comfort when encountered in a similar scent elsewhere. Similarly, in situations of anxiety or joy, certain scents, when encountered again years later, can still trigger corresponding emotional responses.

Gustation is also closely related to olfaction. When we taste a particular food, its flavor often evokes memories of specific moments or situations. Therefore, designers can create emotionally rich and memorable spatial environments by selecting distinctive scents, fragrances that align with the functional requirements of the space, and appropriate scent experience installations. Such designs help individuals to establish emotional connections within a space, leaving a lasting spatial memory.

4. Results: Conceptual Design Scheme

4.1. Project Background

Suzhou Industrial Park is a significant collaborative project between the governments of China and Singapore [116]. The Suzhou Coffee Roasting Factory, located in the Suzhou Industrial Park, is an integrated space that combines coffee roasting, exhibition, and consumer experience. Its site is located at Building A, No. 61 Jiepu Road, Shengpu Sub-district, Suzhou Industrial Park. Within a 2 km radius, there are numerous factories, including food processing plants, technology innovation parks, and equipment manufacturing enterprises, among other light industrial facilities (Figure 10). The factory not only handles coffee production and supply but also aims to attract customers to engage in the coffee-making and tasting process by offering an immersive experience.

4.2. Analysis of the Existing Factory Space

This project is a conceptual renovation proposal targeting Building A, located within the Shengshi Science and Technology Innovation Park in Suzhou. The building is oriented along an east–west axis and occupies a total floor area of approximately 2000 square meters, with a footprint of 70 m in length and 30 m in width and an overall height of 19 m. It comprises two levels, with a clear height of 9 m on the first floor and 7 m on the second floor. Constructed using a reinforced concrete frame system, the structure offers considerable spatial scale and functional flexibility typical of industrial architecture. The facility includes six access points—three cargo loading bays and three emergency exits—distributed along the eastern, northern, and western facades, while the southern elevation lacks direct entry. On the first floor, approximately 300 square meters in the southern section is occupied by a logistics equipment company, with the remaining space largely underutilized. In contrast, the southern portion of the second floor, covering approximately 1700 square meters, is currently used by a coffee processing company for both office and production functions. The spatial layout follows a conventional linear configuration optimized for operational efficiency; however, despite clear functional zoning, the space lacks a systematic design approach that addresses sensory perception or a user-centered spatial experience.

The current spatial conditions present several critical challenges:

• Low spatial utilization: Large areas of the first floor remain vacant, reflecting a disconnect between land resource value and actual functional activation;
• Monotonous circulation: Vertical circulation is concentrated in two staircases located at either end of the building. The considerable floor height and limited lateral connectivity result in constrained movement and a lack of fluid spatial experience;
• Structural constraints on functional expansion: Production activities are fully concentrated on the second floor, where the use of heavy machinery imposes excessive loads on the floor slab, posing potential safety concerns;
• Absence of sensory spatial quality: The original design adopts a purely utilitarian logic, lacking the integration of key sensory dimensions such as lighting dynamics, acoustic quality, olfactory atmosphere, and tactile materials. The resulting spatial ambiance is emotionally disengaging and fails to provide an immersive experience.

4.3. Theme and Design Strategy

The design concept of the Suzhou Coffee Roasting Factory is grounded in the spatial perception theory and the phenomenology of perception. It aims to strengthen the emotional connection between customers and the brand through multi-sensory engagement while enriching the overall user experience (Figure 11). The design not only addresses the functional layout of the coffee roasting and production zones but also emphasizes how users perceive and interact with the spatial environment. By applying a multi-sensory strategy informed by the perception-based theory, the project integrates sight, sound, touch, smell, and taste to create an atmosphere that goes beyond visual esthetics. These sensory dimensions work together to evoke emotional memory, foster a sense of place, and reinforce brand identity, ultimately shaping a more complete and memorable consumer experience.

4.4. Spatial Structure and Circulation Organization

In the initial stages of the design, we referred to and analyzed the interior design characteristics of Adolf Loos’ Müller House. The building’s exterior is simple and unadorned, while the interior is divided through staggered levels and variations in ceiling height, breaking traditional floor relationships and enhancing interaction between spaces [117]. This design concept inspired us to apply it to the spatial structure and organization of the coffee roasting factory, aiming to break the monotony and boundary perception typically observed for traditional factory spaces. It seeks to enhance spatial depth and dimensionality, creating a multi-layered and interactive coffee roasting factory experience.

The coffee roasting factory is divided into three levels (Figure 12a–c). The first level is primarily a visitor-accessible machine processing area, with functional zones including a plant experience area, green coffee bean processing area, roasting area, roasted bean storage area, finished product packaging area, raw and finished product storage area, and a coffee product retail section. The mezzanine area is primarily designed as an interactive experience zone for customers, with functional areas including a central scenic walkway, open lounge, connecting corridor, coffee-making experience zone, roasting experience area, viewing platform, and coffee extraction zone. The second level primarily consists of the coffee museum exhibition area and employee office spaces. Functional zones include an interactive installation experience area, corporate culture display area, coffee culture exhibition area, digital experience dome, children’s activity zone, coffee employee training area, staff offices, and a coffee sustainability exhibition zone.

4.5. Application of Spatial Perception Design Strategies

This section offers a systematic analysis of four representative spatial zones within the factory to verify the multi-sensory spatial perception strategies proposed in Section 3. Each subspace is conceptualized as a distinct perceptual scenario wherein emotional ambiance, cross-modal sensory integration, and embodied interaction are deliberately orchestrated to facilitate an immersive and affectively resonant user experience. The five sensory modalities—visual, auditory, tactile, olfactory, and gustatory—are purposefully embedded into corresponding spatial elements. Collectively, these zones exemplify how phenomenological principles, sensory integration, and emotional atmosphere operate synergistically to construct a coherent and immersive experiential system.

4.5.1. Factory Entrance Area

As a critical spatial threshold, the entrance area of the factory orchestrates the psychological and perceptual transitions from the external industrial environment to the multi-sensory interior. From the perspective of spatial perception theory, this area functions not only as a physical passage but also as a “perceptual activator”, establishing the emotional tone of the overall spatial experience through coordinated multi-sensory stimulation. Drawing on the phenomenological theory—particularly Merleau-Ponty’s insights—the body’s initial encounter with a space elicits a pre-reflective emotional resonance: an immediate, embodied sensation perceived directly through the senses prior to cognitive processing. This embodied perception plays a vital role in forming spatial memory and emotional attachment.

The entrance integrates visual, auditory, tactile, and olfactory dimensions to create an immersive arrival experience. Visually, the design emphasizes harmonious color palettes and lighting to evoke a warm, contemporary atmosphere. The use of rose gold metallic hues and neutral beige tones, in combination with the natural shades of coffee beans, creates a welcoming and modern spatial identity. The spatial interplay between the spiraling ramp and the five-meter-high roasting silo enhances users’ awareness of scale and movement, guiding both kinesthetic and visual perception. This contrast not only enriches the spatial rhythm but also directs the visual focus, underscoring the importance of spatial form language (Figure 13a). On the right, the plant zone acts as a secondary visual anchor; its greenery contrasts with the surrounding cool tones, and the organic form and colors of the plants demonstrate how biophilic design and chromatic dynamics guide attention and convey emotional depth and spatial layering (Figure 13b). In the auditory domain, soft ambient music is seamlessly embedded into the entrance environment, establishing a calming mood. This aligns with Schafer’s soundscape theory (1993), which posits that sound actively shapes perception, orientation, and emotion [53]. The rhythm of the music is synchronized with pulses of ambient light, generating a temporal–spatial experience that enhances immersion and situational awareness. Tactile engagement is promoted through digital touchscreens positioned near the roasting display and plant area. These interactive devices invite users to explore the spatial narrative and layout of the factory. Material contrast is also intentionally applied: smooth digital interfaces are juxtaposed with textured plant containers and natural wood surfaces to stimulate active tactile perception. This approach resonates with James J. Gibson’s theory of affordance, and he, in his ecological approach to visual perception (1979), emphasized that perception and action are inseparable—objects suggest possible actions based on their physical and perceptual properties [118]. In the olfactory layer, the aroma of roasted coffee mingles with the freshness of the plant area to form a rich olfactory field. This multi-layered scent environment enhances the sense of place and serves as a sensory memory trigger. It evokes emotional recollection, echoing the Proustian memory effect, wherein scent deeply activates memory and emotion [119].

In summary, the entrance transcends its functional role to become an emotional gateway through the precise orchestration of sensory elements and material strategies. It fulfills multiple functions: embodied perception, emotional activation, and spatial orientation. This reflects the core of phenomenological design, where a space is not merely observed but lived through the body—integrating memory, emotion, and perception from the very first step.

4.5.2. Mezzanine Coffee-Making Experience Zone

The mezzanine coffee-making experience zone is deliberately designed as a participatory spatial node that reinforces multi-sensory integration through active engagement of touch and taste. Rather than serving solely as a site for demonstration or operation, this area functions as an embodied perceptual field, inviting users to move, select, smell, touch, and taste. Spatial perception here shifts from passive observation to an actively constructed multi-sensory experience, aligning with the embodied cognition theory, which emphasizes that perception arises through the dynamic interaction between the body and the environment. The spatial design supports this by integrating functional tasks—such as brewing, grinding, and tasting—with tactile and gustatory cues that engage the full body. The physical movements required to navigate the space and interact with tools further enhance the sense of immersion, transforming the act of coffee making into a multi-sensory ritual that strengthens spatial memory and emotional connection (Figure 14).

Visually, a series of suspended curved installations are strategically arranged to guide movement. Their variation in height and reflective surfaces generates a layered sense of spatial rhythm and visual tempo. According to Gestalt principles of spatial perception, form and flow inherently guide perception and elicit intuitive movement. An interactive lighting system further enhances the embodied visual engagement by responding to users’ positions and gestures, transforming vision from a passive observation into an active spatial behavior—one of the key elements in embodied phenomenology. Auditory perception is subtly activated through the soft “ticking” sound of coffee beans falling, creating a micro-rhythmic temporal marker within the space. Though not dominant, these sounds gently regulate the pace of user behavior, contributing to a textured acoustic environment that resonates with the rhythm of hand-crafted coffee making. This sensory tempo reflects the phenomenological notions of time—not as abstract but as embodied and experientially perceived. Olfactory stimuli play a crucial role in establishing emotional resonance and spatial memory. Fourteen distinct scent modules are embedded throughout the area, each corresponding to a specific origin of coffee beans and its cultural narrative. These modules encourage users to compare aromas, form emotional associations, and recall personal memories. This olfactory map draws on the Proustian memory effect, whereby scents bypass rational processing to directly evoke affective memory. Thus, the space gains emotional memorability, reinforcing individual identity and deepening the immersive experience. Taste brings the sensory experience to its culmination. Users can sample coffee made from beans they selected themselves, completing the sensory loop with a sense of personal ritual and narrative closure. This transforms a simple act of consumption into a personalized, embodied experience. In doing so, users shift from observers to sensory participants, cultivating a sense of intimacy and belonging within the space—an essential component in experience-oriented spatial design for achieving emotional immersion and lasting memory.

4.5.3. Second-Floor Interactive Installation Experience Zone

This zone demonstrates a phenomenological immersive experience facilitated by digitally augmented reality, where technology acts as a mediating agent of perception, deepening users’ spatial engagement. Through the coordinated integration of visual, auditory, and tactile elements, the space is constructed as an experiential field—one that can be sensed, explored, and co-constructed in real time. Users are no longer passive observers but active participants in the continuous creation of spatial meaning.

At the center, a tree-shaped interactive installation employs programmable LED lighting to simulate the flow and layering of time. Light gradually spreads across the canopy and responds to users’ footsteps on the ground with radiating halos. This interplay between light and the body exemplifies Gernot Böhme’s theory of atmosphere [85], wherein light functions not merely as illumination but as a temporal and emotional medium capable of subtly influencing mood and spatial awareness (Figure 15). Auditory design further amplifies the sense of immersion. A spatial sound system integrates ambient background noise with gesture-triggered localized audio responses, producing a dynamic soundscape that evolves with user behavior. This responsive acoustic environment follows the logic of spatiotemporal control, using sound as a medium to modulate dwell time, emotional rhythm, and behavioral orientation within the space. Tactile interaction is encouraged through touchscreen interfaces (Elo Touch Solutions, Milpitas, CA, USA) and gesture-recognition-based projection systems, empowering users to engage actively and assume agency in the discovery of content. This mode of interaction aligns with the phenomenological concept of the “lived body”, where perception is not a passive reception of stimuli but an experiential process shaped by bodily engagement, relational context, and intentional action.

Overall, this area exemplifies how digital interactivity and spatial perception strategies can be integrated to reshape the experiential paradigm of contemporary exhibition spaces. It marks a shift from a static observation to a relational, emotional, and participatory perceptual environment, where users do not merely receive information but become immersed in a bodily atmosphere and individualized emotional resonance.

4.5.4. Second-Floor Coffee Culture Exhibition Area

This area guides users into a more contemplative and introspective emotional state, offering a rhythmic contrast to the sensory dynamism of the lower levels. The spatial strategy emphasizes material authenticity, biophilic design, and the subtle integration of natural light as a means of emotional modulation. Drawing on Peter Zumthor’s theory of atmosphere, the tactile presence of coarse stone walls evokes a sense of rootedness, stability, and timelessness, constructing emotional depth through the materiality of presence.

A circular skylight gently filters natural light onto centrally planted coffee trees, crafting a biophilic narrative that fuses nature and culture (Figure 16). This design facilitates emotional restoration and psychological comfort, echoing findings in environmental psychology that link natural elements to reduced stress and enhanced well-being. From a phenomenological perspective, the slow movement of light across different material surfaces fosters attentiveness and heightens the bodily perception of spatial rhythm and temporal flow. Contrasts between materials—such as smooth versus rough and natural versus artificial—deepen tactile engagement. These juxtapositions prompt indirect tactile perception, allowing users to form unconscious emotional connections with materials. The sensation of touching a rough stone or the warmth of wood triggers material memory, reinforcing a sense of spatial intimacy and authenticity.

At the end of the exhibition path, an AI-driven immersive VR dome integrates technological innovation with emotional personalization. Users input keywords (e.g., “warmth”, “floral”, or “forest”), which the system translates into a customized audiovisual environment that simulates an idealized coffee world (Figure 17). This synesthetic interface transforms abstract emotional cues into concrete spatial visuals and soundscapes, embodying a cutting-edge, user-centered model of multi-sensory design. It illustrates how emotional atmospheres are no longer solely constructed by the designer, but can be co-created through digital media—marking a new paradigm in experiential spatial design.

4.6. Virtual Reality Technology and 3D Modeling in Spatial Design

The integration of virtual reality (VR) technology and 3D modeling in spatial design is increasingly becoming an innovative approach in the field of interior design. After completing the initial spatial design, the team used VR technology for an immersive experience to more intuitively perceive the design effects, spatial layout, and details of sensory experiences (Figure 18a). Through VR technology, designers can “enter” the virtual space, experiencing the atmosphere, proportions, light and shadow effects, and sensory interactions in a realistic way. This allows them to effectively identify potential issues in the design and make real-time adjustments. This highly interactive approach not only helps designers optimize the spatial layout but also allows clients to “experience” the space in advance and provide feedback for improvements.

Additionally, the team also brought the virtual design to life by printing 3D models (Figure 18b). With 3D printing technology, designers can quickly create physical models of the space, further validating design details, particularly in terms of material selection, spatial proportions, and structural integrity. This model allows both designers and clients to see the actual effect of the design more clearly, reducing errors and providing a more accurate reference for the final presentation of the space.

The integration of VR technology and 3D printing not only enhances the visualization and interactivity of spatial design but also significantly improves the efficiency and accuracy of the design process. Designers can conduct multiple tests and adjustments in the virtual space, optimize details of the physical model, and ultimately achieve the most ideal design outcome. Clients and the project team can better understand the potential and sensory effects of the space through immersive experiences and 3D models, enhancing the accuracy and satisfaction of design decisions. In addition, we created a promotional video. This video showcases the promotional film produced for the Suzhou Coffee Roasting Factory, available in the Supplementary Materials: Video S1.

4.7. Comparative Analysis of Pre- and Post-Renovation Design

To evaluate the practical impact of the proposed multi-sensory design strategies, this study conducted a systematic comparative analysis of the spatial conditions before and after the conceptual renovation of the Suzhou Coffee Roasting Factory (

Table 3. Comparative analysis of the coffee roasting factory before and after renovation.

Design Dimension	Before Renovation	After Renovation
Spatial Layout	Linear and utilitarian	Multi-layered circulation with spatial rhythm
Lighting	Uniform artificial lighting	Integration of natural skylights, directed artificial lighting, and temporal variation
Acoustic Environment	Industrial noise or silence	Soundscape design and interactive sound
Material and Tactility	Exposed concrete and emulsion-painted wall	Warm natural materials combined with rose gold metal finishes and rich tactile interfaces
Scent and Taste Design	None; no olfactory or gustatory cues present	Coffee aroma diffusion, scent-zoned areas, and sensory–emotional pairing
Circulation and Accessibility	Vertical, disconnected movement limited to staircases	Horizontally connected, guided pathways enhancing spatial continuity
Emotional Atmosphere	Neutral, emotionally detached	Immersive, emotionally engaging with sensory layering
User Experience (Expected Impact)	Passive, functional use; low engagement	Active, exploratory, and memory-forming experiences

).

• Before renovation: The original site was a prototypical industrial facility with a spatial layout primarily driven by production efficiency. Circulation followed a rigid, linear, and enclosed pattern, with minimal access to natural light and no deliberate use of color or sensory-oriented design elements. The overall spatial atmosphere was utilitarian in nature, lacking emotional expression and offering limited opportunities for user engagement or affective resonance;
• After renovation: The redesigned space integrates multi-sensory strategies grounded in the spatial perception theory and phenomenology, creating a dynamic and immersive environment. These strategies include multi-layered spatial relationships that encourage exploration, a carefully curated lighting design that modulates the spatial atmosphere, and the creation of a soundscape that enhances emotional resonance. The use of tactile materials and textures, alongside scent-driven ambiance, further enriches the sensory experience. Overall, these interventions not only improved the functional flow of the space but also fostered deeper emotional engagement, offering users a more holistic, immersive, and emotionally resonant spatial experience.

For further technical drawings, including material specifications, floor system diagrams, elevation drawings, and construction details, please refer to the Supplementary File.

5. Discussion

This study is grounded in the theory of spatial perception and explores how multi-sensory design strategies can enhance sensory experiences within interior environments. Using the Suzhou Coffee Roasting Factory as a conceptual design case, the project examines the integration of visual, auditory, tactile, olfactory, and gustatory dimensions with spatial strategies to construct immersive experiential environments. Developed and led by the authors, the project aims to demonstrate how theoretical principles of spatial perception and multi-sensory design can be translated into a tangible architectural and interior design language. It is important to note that all images presented in this article are digital renderings created during the design phase and do not depict photographs of an actual built space.

In Section 3, a range of case studies are analyzed and synthesized to outline how multi-sensory design strategies can be applied under the guidance of spatial perception theory. These strategies contribute to enriching the sensory dimensions and emotional atmosphere of interior spaces, offering a reference point for the development of future experience-oriented design approaches. However, since this study is based on a conceptual project that has not yet been constructed, the further exploration and validation of broader practical contexts are necessary to support the ongoing development of perceptual and emotional aspects of interior design.

5.1. Theoretical Contributions

This study holds significant academic value, as it provides a novel theoretical framework through a comprehensive analysis of the multidimensional factors of spatial perception. It enriches the existing research on spatial perception and multi-sensory design, offering new perspectives on how spatial design influences customers’ emotional experiences and behaviors. The theoretical contribution of this study lies not only in the proposal of multi-sensory design strategies but also in its systematic analysis, engaging with the existing literature and advancing the further development of the spatial perception field.

• This study, grounded in the phenomenological theory of perception, proposes a spatial perception design strategy centered around multi-sensory design. The theory of phenomenology of perception emphasizes the role of human sensory experiences in shaping an individual’s perception of the world [8]. In the context of architecture and interior design, while the existing research has explored the sensory dimensions of spatial perception [120], these studies often focus on the impact of a single sense. In contrast, this study proposes several key design strategies by considering multiple sensory elements, including light, color, form, sound, touch, and scent, to regulate the emotional ambiance of the space and enhance the customers’ sensory experience. These strategies include the following: (1) the construction of visual perception: regulating the emotional ambiance of space through color and light, enriching the spatial form language, and enhancing the depth of visual perception; (2) auditory perception design: soundscape design, the temporal control of sound, the contextual guidance of sound, and immersive sound interaction experience; (3) the application of tactile perception: the creation of direct and indirect tactile perception; and (4) the integration of olfactory and gustatory perception: the selection of scent and the creation of emotions, the creation of memorable scent spaces, etc. The existing research, such as Lee Keunhye’s study, has pointed out that the synergistic interaction of sensory elements significantly impacts emotional experience [1]. Building on this fact, this study further validates this idea, demonstrating how these sensory elements work together to create a spatial ambiance with emotional regulation capabilities. The combination of light, color, and form can regulate the visual effects of a space, while sound and scent enhance immersion and emotional connection, complementing the dimensions that visual perception alone cannot provide;
• According to the existing literature, spatial perception is not solely an experience of a single sense but is achieved through the interaction of multiple senses [121]. For example, Spence C. suggested that multi-sensory elements such as vision, hearing, and touch in interior design can significantly enhance the user’s spatial experience [16]. In this study, we illustrate the above-mentioned perspectives through a conceptual design case. In the spatial proposal for the Suzhou Coffee Roasting Factory, visual elements—such as dynamic lighting, material textures, color schemes, and the curved form of the coffee bean installations—are combined with auditory experiences (e.g., ambient music and the rhythmic sound of falling coffee beans) and tactile interactions (including material contrasts and immersive touch-based installations). Together, these elements create a rhythmic and dynamic spatial atmosphere. This practice validates the influence of strategies of visual, auditory, and tactile perceptions on customers in commercial spaces, as proposed by Spence C. (2014) [122]. It demonstrates that the design of spatial ambiance can effectively enhance customer experience and shopping behavior, guide emotional responses, and increase the sense of immersion in the space, thereby boosting purchasing intent. It should be noted that this project is a conceptual design, and the analysis is grounded in the theoretical integration of sensory strategies with spatial design principles rather than empirical user testing. Future studies could extend this work by incorporating user feedback and behavioral analytics to further assess the practical implications of multi-sensory strategies in built environments;
• In addition, this study also analyzes the importance of olfaction and gustation in interior spaces and proposes relevant design strategies, aligning with the findings of Madzharov, Block, and Morrin (2015), who noted that scent and taste can effectively enhance the sensory appeal of a space, thereby influencing customer preferences and purchasing power [123]. In this study, the use of coffee aromas and interactive coffee bean selection not only enhanced the olfactory experience of the space but also stimulated customers’ gustatory needs, thereby increasing their brand loyalty and the memorability of the space. In addition, this study analyzes how the selection of scent directly affects people’s emotions and memory. This is similar to the conclusion drawn by Ehrlichman et al. through their experiments, which suggests that when the emotions triggered by a scent align with the emotional content of a memory, the emotion can influence the content of the recalled memory [124].

Thus, this study not only provides an in-depth expansion of theoretical research on spatial perception, filling a gap in the field of multi-sensory design, but also offers systematic theoretical support for spatial design in practice through detailed design strategies. It advances the design thinking process from a singular focus on functionality to one centered around a multi-sensory experience.

5.2. Practical Implications

This study provides several actionable strategies and recommendations for interior design, particularly in the areas of multi-sensory design and emotional regulation, offering practical guidance for designers, brands, and related professionals.

• This study emphasizes the role of color and lighting modulation in visual design in shaping the spatial ambiance. Designers should flexibly use color and lighting to adjust the emotional tone of a space based on the functional requirements of the space and the emotional needs of the target customers. For example, in leisure and cultural spaces, warm tones and soft lighting create a relaxed atmosphere, helping to regulate customers’ emotions. In contrast, in commercial retail spaces, cool tones and ample lighting contribute to a sense of energy and engagement, encouraging customer interaction and purchasing behavior. Therefore, designers should consider the functional needs of a space and the emotional needs of the customers, using flexible combinations of color and lighting to meet diverse emotional experiences;
• Sound design and soundscape management are crucial for enhancing the sense of immersion in a space. Through precise soundscape design, designers can significantly enhance the customer experience, particularly in public spaces, commercial environments, and cultural venues. Soundscape design should not merely involve the selection of background music but also consider the rhythm, volume, and contextual integration of sound. For example, in dining spaces, soft background music and natural sound effects can create a relaxed and comfortable dining atmosphere for customers. In retail spaces, the alignment of music with the brand image can evoke emotional resonance in customers, enhancing their sense of engagement and desire to purchase;
• The design of touch and scent has a significant impact on the emotional ambiance of a space. Although touch and scent are often regarded as secondary design elements, their role in enhancing spatial appeal and improving customer memory is becoming increasingly important. Designers should consider using different tactile experiences through material selection and spatial layout details to enhance the depth and affinity of a space. Meanwhile, scent design, especially fragrances that evoke emotional connections with customers, can significantly increase brand loyalty and the memorability of a space. In commercial spaces, scent design should be closely aligned with the brand image by selecting appropriate fragrances to enhance customers’ emotional experience and strengthen their emotional connection with the brand, thereby boosting their purchasing intent.

5.3. Limitations of the Study

Although this study demonstrates the effectiveness of spatial perception design through practical case studies, it also has some limitations.

First, this study is based on a single case. This study is primarily based on the analysis of the Suzhou Coffee Roasting Factory case. While the results are somewhat representative, different types of commercial spaces, cultural contexts, and user groups may have varying impacts on spatial perception experiences. Therefore, the generalizability of the findings may be somewhat limited.

Second, this study primarily explores design strategies through an in-depth, case-based analysis of multi-sensory experiences in spatial design. However, the lack of quantitative data may limit the broader applicability and statistical validation of the findings. While the case analysis offers preliminary insights into users’ subjective experiences and emotional perceptions within multi-sensory environments, it does not enable the objective quantification of sensory responses or facilitate comparisons across a wider population. Future research should focus on quantifying sensory experiences and correlating them with specific spatial design elements.

Third, this study lacks an in-depth analysis of cultural and individual differences. The project is embedded in the cultural context of Suzhou, and local traditions may influence the transferability of the design strategies to other cultural or geographical settings. People from different cultural backgrounds may exhibit significantly different responses to sensory stimuli such as color, sound, and smell. For example, certain colors may symbolize positive emotions in one culture while evoking negative associations in another. In addition, individual differences—such as age, gender, occupation, and physical health—can also affect how people perceive and experience space. Future research should explore how these cultural and individual differences influence the effectiveness of multi-sensory design in order to develop more tailored spatial solutions for diverse target groups.

Fourth, the generalizability of study results is limited by technological factors. With the rapid development of virtual reality (VR), augmented reality (AR), and artificial intelligence (AI) technologies, future research on spatial perception should further explore how emerging technologies can enhance sensory experiences. Although this study incorporates a digital experience design, its application at the technological level remains relatively limited.

Fifth, as the Suzhou Coffee Roasting Factory is a conceptual design project that has not yet been constructed, only preliminary technical drawings are available at this stage. Other design documents, such as acoustic diagrams, scent diffusion system details, tool specifications, and implementation phase documentation, have not yet been developed. In addition, this study does not currently incorporate post-occupancy evaluation (POE) or user-centered feedback mechanisms such as structured observation, user research, or performance assessment. The evaluation of design strategies is primarily based on theoretical alignment and conceptual application rather than empirical user validation. We acknowledge this as a limitation of the study and suggest that future research include feedback from users and design professionals to further assess the effectiveness of multi-sensory spatial strategies in real-world settings.

6. Conclusions and Future Research

6.1. Conclusions

This study, centered around spatial perception, explores how multi-sensory design strategies can enhance user experience in interior spaces and proposes a systematic design framework. By integrating the spatial perception theory and the phenomenology of perception, this study provides an in-depth analysis of the key factors influencing spatial perception and summarizes the fundamental characteristics of spatial perception—relative scale, ambiance, and bodily behavior. Through case analysis, this study further clarifies how the subjective elements of spatial perception (vision, hearing, touch, smell, and taste) and objective elements (nature, materials, light and shadow, and color) work synergistically to shape the emotional ambiance of the space, enhance immersion, and elevate the emotional experience of users. Specifically, the subjective elements—senses—serve as the core components in the perceptual process, directly influencing users’ cognition and emotional responses to the space. Meanwhile, the objective elements—the physical attributes of the space, such as natural elements, material textures, light and shadow effects, and color combinations—provide the foundation for sensory stimulation and experience.

Although the understanding of spatial perception theory has become an important societal issue in contemporary architecture, research on its impact on interior space experience and design strategies remains limited [1], with the existing studies primarily focusing on spatial functionality and visual significance. In this study, we found that spatial perception is not limited to the presentation of functionality and visual effects but is a comprehensive, multi-sensory interactive experience. Therefore, based on multi-sensory design in spatial perception, this study proposes a new strategy for interior space design:

• Visual design (such as color, light and shadow, and spatial form language) effectively shapes the emotional ambiance of a space by regulating emotions and psychological expectations. We explore three key aspects: first, the perception of temperature, scale, and depth in color, where the combination of warm and cool tones and contrasts influences the emotional expression of the space; second, the intensity and direction of and color temperature variations in natural and artificial lighting, which significantly adjust the atmosphere of the space, enhancing its liveliness or tranquility; and finally, the spatial form language, contrast, variation, permeability, layering, sequence, and rhythm guide visual flow and enhance the spatial depth and dynamism through the layout and size differences in spatial elements, thereby deepening the emotional and psychological impact of the space;
• Auditory design (such as soundscapes, temporal control of sound, etc.) is crucial for the comfort and sense of immersion in a space. We explore four aspects: soundscape design, which creates an auditory environment that aligns with the spatial ambiance; the temporal control of sound, adjusting the duration of and variation in sound to optimize emotional rhythms; sound contextual guidance, using specific sound effects to elicit emotional responses; and immersive sound interaction, which enhances sensory experiences through interactions with the space via digital media technology;
• Tactile design (including direct and indirect touch) enriches the sensory experience of the space through variations in materials, temperatures, and textures. Direct touch stimulates sensory responses through contact with surface materials, while indirect touch influences users’ psychological perceptions through the overall layout of the spatial environment and material properties (such as temperature and humidity), enhancing their overall cognition and emotional connection to the space;
• Olfactory and gustatory design stimulates memory and emotional connections through scent, adding a deep emotional dimension to the space and enhancing users’ immersive experience and brand identity. Specific scents can evoke emotional responses tied to individuals or cultures, enhancing the uniqueness of the space. Gustatory design, in turn, strengthens the emotional connection between users and the space, particularly in dining and commercial environments.

Following the proposed multi-sensory design strategies for interior spaces, this study presents a conceptual design case—the Suzhou Coffee Roasting Factory—to explore the potential application of these strategies in practice. By carefully composing elements such as lighting, colors, materials, and scents, the project aims to create a space that is both functional and rich in sensory stimulation. This case offers a concrete theoretical reference for designers, illustrating how multi-sensory design strategies can enhance the sensory experience and emotional atmosphere of interior environments.

As this study centers on a conceptual design proposal, certain aspects may reflect the researchers’ subjective interpretations, and the generalizability of the findings may be limited. However, the analysis of design strategies is supported by a wide range of precedent cases, which enhances the methodological credibility and aligns with the qualitative analytical frameworks commonly adopted in spatial perception research. Building on this foundation, future research could further explore quantitative methods for evaluating sensory stimuli in multi-sensory design. Techniques such as physiological feedback and behavioral tracking may enable the more precise assessments of how various sensory inputs influence spatial experience. Additionally, attention should be paid to the fine-tuning of sensory stimuli during spatial atmosphere creation to ensure coordination across sensory dimensions while avoiding overstimulation. Cross-cultural differences in sensory perception, along with the application of multi-sensory design in various spatial typologies—such as educational, healthcare, and commercial environments—also represent promising directions for further investigation. These inquiries would contribute to refining sensory design strategies and improving their adaptability to diverse cultural and functional contexts. Moreover, the rapid development of technologies such as artificial intelligence (AI), virtual reality (VR), and augmented reality (AR) presents new challenges and opportunities for traditional theories of spatial perception and interior design practices. Future research may consider how these emerging technologies can be integrated with multi-sensory design to optimize spatial experiences and expand the potential of sensory-based design approaches.

In conclusion, this study not only provides theoretical support for interior spatial design but also establishes a practical framework for implementation, offering significant academic value and practical relevance.

6.2. Future Research

Future research could focus on the quantitative analysis of sensory design, cross-cultural applications, and the integration of emerging technologies, further advancing the application of spatial perception theory in interior design and creating more immersive and interactive spatial environments. To this end, future research can be explored from the following perspectives:

• Quantitative evaluation methods for multi-sensory design: Future research will aim to establish a more scientific framework for the quantitative evaluation of multi-sensory design. This may involve the use of biometric feedback, data analytics, and psychological experiments, such as electroencephalography (EEG), galvanic skin response (GSR), and eye-tracking technologies, to accurately assess the specific impacts of multi-sensory design on spatial perception. In addition, future studies will apply the proposed design strategies to built projects, conducting evaluations through user or visitor data collection methods such as behavioral observations, questionnaires, interviews, and onsite studies. These findings are expected to provide data-driven support for designers, enabling more informed and evidence-based decision making in the design process;
• Refined control of multi-sensory design: Future research should delve into how to fine-tune the intensity and combination of sensory stimuli such as vision, hearing, touch, smell, and taste to avoid discomfort caused by overstimulation while enhancing the personalization and precision of sensory design. By incorporating findings from physiology, psychology, and neuroscience, studies can explore the “thresholds” of sensory stimuli and the optimal combinations, thus providing more tailored sensory experiences for different spatial environments and user needs;
• In-depth study of cross-cultural and individual differences: Individual differences such as cultural background, age, gender, and social roles have a significant impact on spatial perception. Future research should explore how these differences shape sensory experiences and tailor spatial design solutions to meet the needs of various groups. Additionally, studies should examine how different cultures have varying preferences for spatial design elements (such as color, sound, and scent), providing guidance for spatial design in a globalized context;
• Intelligent and personalized spatial perception design: With the advancement of artificial intelligence (AI), big data, and sensing technologies, future research should focus on exploring how to achieve personalized and adaptive spatial design through intelligent systems. By analyzing user behavior data and emotional feedback, smart systems can be designed to dynamically adjust spatial sensory elements (such as lighting, sound, temperature, etc.), thereby enhancing the interactivity and immersion of the space;
• Fusion of virtual and physical spaces: The rise of virtual reality (VR) and augmented reality (AR) technologies has opened new avenues for spatial perception research. Future studies can explore how to integrate sensory experiences in virtual spaces with those in physical spaces, achieving a seamless transition between the virtual and real and creating an immersive experience that bridges both realms. This includes enhancing the realism of sensory simulations, such as touch, smell, and taste, in virtual spaces as well as optimizing the interactive experience between virtual spaces and the physical environment.