Insights / urban

Invisible design

As we consider the role of our non-visual senses — sound, touch, smell, and taste — in our built environment, architects are uncovering the surprising benefits that come with creating immersive urban sanctuaries.

Faridah Samsuri, Associate Director
Ooi Phaik Sim, Architectural Researcher
Wong Lei Ya, Architectural Researcher
March 2023


Designers have much power over whether occupants feel relaxed or pressured in the environments they design for them. The authors discuss how the use of familiar elements such as plant motifs can help patients to stay calm in a clinical setting. The use of scents and sounds to create scentscapes and soundscapes is also gaining traction as designers seek to find ways to help users differentiate between spaces for rest and spaces for work; as well as enter psychological states of focus and concentration. Designers also have the responsibility of using appropriate materials to avoid odourless pollutants in a working space. They also look at the use of non-recirculated air in interior spaces to flush out invisible toxic microbes in Singapore’s first new-built net zero building, SDE4, on the campus of National University of Singapore, which champions indoor air quality and comfort, and energy efficiency by reducing the use of air-conditioning while keeping users cool and comfortable.

“Spaces, places, and buildings are undoubtedly encountered as multisensory lived experiences. Instead of registering architecture merely as visual images, we scan our settings by the ears, skin, nose, and tongue.”

Juhani Pallasma
Finnish architect and theoretician, and author of The Eyes of the Skin: Architecture and the Senses

The environment which we are immersed in has an unconscious effect on our being. For example, most people can identify with experiencing some form of stress and anxiety while being in a doctor’s waiting room. It is the anticipation of the unknown, whether it is just a routine check-up or a long-drawn battle with an acute illness, that causes white-coat anxiety. In 2013, a study found that between 15 and 30 percent of high blood pressure readings taken at a doctor’s office might have resulted from such anxiety.

Post-pandemic, society has become more aware of the importance of our connection to nature for health and wellness, sparking more interest to look towards nature for solutions to the design issues that urbanisation brings.

Biophilia – an age-old intuitive desire to be close to nature

Historically, nature has played a role in the design of homes and public spaces. The paper, “14 Patterns of Biophilic Design”, published by Terrapin Bright Green, an environmental consulting and strategic planning firm, sets up three categories within a framework to understand the strategies of incorporating nature into the modern built environment.

The section, “Nature in Space”, focuses on the direct physical connection to nature. It includes visual and non-visual experiences of nature through the incorporation of elements such as water, daylight, breeze, greenery or the use of natural materials in interior spaces, the use of sounds of a water feature, or the aroma of herb gardens to soothe people using the space.

Using “natural analogues”, designers can also reinterpret patterns and systems characteristic of the natural world by choosing materials reminiscent of nature, or naturalistic shapes and forms, with the purpose of calming the senses. Lastly, designs that incorporate the “nature of the space” use spatial configurations in nature to seek refuge and protection, to allow users to experience the mysteries and thrills of nature.

Biophilic elements are important aspects in humanistic interior design for the post-pandemic age. Biophilic spaces reduce stress and anxiety, enhance mood, restore concentration and creativity, provide a sense of vitality, and even expedite healing. How do we seek out these restorative invisible elements in the design of a holistic built environment, in a healthcare environment for instance, where biophilic elements can provide healing beyond medical care?

“Biophilic spaces reduce stress and anxiety, enhance mood, restore concentration and creativity, provide a sense of vitality, and even expedite healing. How do we seek out these restorative invisible elements in the design of a holistic built environment?”

The use of biophilic elements to alleviate anxiety and promote healing

In a healthcare setting, architects and designers have a duty towards creating spaces which help support a person’s holistic journey of recovery. This duty extends beyond the patient to care providers, caregivers, and medical professionals. A patient’s state of mind could either enhance or impede one’s journey towards healing and recovery. A 1995 study found that wounds on patients who were under stress took longer to heal than those on patients who were able to recover in an environment with less pressure. Another study from Texas Tech University in the United States investigated the impact of eight environmental elements, namely nature, lighting and music, on the health outcomes of patients within the hospital setting. It was found that patients who were exposed to nature, such as indoor plants, while recovering in a hospital setting felt less anxious than patients who were exposed to none.

Traditionally, architecture has been dominated by the sense of sight. In designs where visual aesthetics take precedence, nature and biophilic elements for wellbeing are presented visually to create a sense of comfort and calm.

Take the example of the Makati Medical Centre’s Women Wellness Centre in the Philippines, where human-centric designs are prioritised to support a relaxing, holistic journey of recovery, addressing the healthcare needs of women.

The centre’s main reception area is designed to resemble a refuge in the woods, providing a comforting sense of protection to visitors. A bamboo mirror wall feature at the lift lobby is a delightful surprise as people can see their reflection amidst a bamboo forest despite being in a clinical setting. Bamboo is intrinsic to the culture of Philippines, from lush bamboo gardens in memories of childhood play, to the daily furniture that families use in their homes. The sight of the bamboo forest momentarily transports one to a more familiar and comforting setting. The bamboo feature wraps around the corner and brings the visitor’s eye to a multi-layered floral printed wall panel.

Visitors in the corridors and waiting lounges can enjoy beautiful views of the city. Ambient natural light fills the waiting lounge, entering via wide panoramic windows filtered by timber screens. The waiting area feels like a lush garden. The main activity zone for the Rehabilitation Clinic is designed as an open space with plenty of unblocked views and daylight. Special care went into the selection of the flooring material that has a deodorising effect, preventing unpleasant smells and creating a healing-centred environment.

“A bamboo mirror wall feature is a delightful surprise as people can see their reflection amidst a bamboo forest despite being in a clinical setting.”

Makati Women Wellness Centre’s main reception area has a bamboo mirror wall (top left and top right images) that creates a harmonious arrival experience which calms, comforts, and alleviates the anxiety of medical treatment. The rehabilitation areas (bottom right image) and waiting lounge (bottom left image) offer panoramic views of the city and ambient daylight, allowing artificial lighting to be dimmed or switched off at certain times of the day, creating an energy-efficient indoor environment. (Photography: Artem Levy)

The invisible bonding agent

In recent years, architects and designers have started to consider the role played by the other non-visual senses, namely sound, touch, smell, and taste in our built environment, in promoting social, cognitive, and emotional development.

The sense of smell has the greatest connection to memory and emotions compared to the other senses. The smell of our favourite comfort food can transport us back to our childhood memories in an instant; pleasant smells can significantly uplift our daily emotions and moods.

During the pandemic, much of our time was spent in our homes. Boundaries between work, family, and relaxation were blurred and intertwined. In response, designers have explored the idea of “scentscaping” homes using essential oils, flowers, or diffusers to redefine zones for working, sleeping, and resting. By using distinctive scents in each space, spaces can be zoned for work or relaxation, restoring boundaries in the home for better mental wellbeing. In other settings like retail, scentscaping has long been introduced in shopping malls, where a distinctive scent is used to create a pleasurable experience for shoppers and to define a unique corporate brand and identity for the retailer.

In Singapore, where people bond over food and drinks, a taste for coffee brings a community together. Within the residential and transit-oriented development, Eastlink I and II @ Canberra, lies Canberra Plaza — a new-generation three-storey neighbourhood centre that serves as a one-stop destination for its residents and the public.

Amongst its many facilities is a family lounge designed for communal use, where people can read, mingle over coffee, or work. Natural daylight from the adjacent central atrium skylight illuminates its bright interior, and provides a warm feeling to the place. The aroma of coffee and fresh bakes coming from the café anchors the place. This community space forms a scentscape and personality of its own, drawing visitors to it.

The family lounge at Canberra Plaza is an inclusive community space defined by its scentscape.

Navigating urban soundscapes for acoustic wellness

Living in a dense urban environment, city-dwellers have become desensitised to the myriad unpleasant sounds surrounding us. The constant hum of a nearby expressway or rail network, open plan offices, and working from home, are some scenarios where the indoor acoustic environment is influenced by the exterior.

Yet, urban noise pollution can interfere with our health, sleep, concentration, and productivity. The need for acoustic wellbeing becomes more pronounced in residential homes often requiring natural ventilation – where both sound and wind could enter. A case in point is a study involving a large population base in Ontario, Canada, which found that people living close to major roads with heavy vehicular traffic have an increased occurrence of dementia.

“Acoustic comfort is an important aspect of design which is largely invisible to us. How can we create healthy acoustics indoors by balancing and regaining control of the unpleasant and pleasant?”

In the design of open plan offices, appropriate material selection for acoustic absorption and reverberation should be considered along with acoustic masking strategies. Nature-inspired biophilic soundscapes were installed and tested at a company’s headquarters in Michigan, in a space designed for focused work.

This has since become one of the most utilised spaces on the work campus. Research carried out to test the effects of a biophilic soundscape in a London-based workplace found that workers experienced increased relaxation and focus, and creative thinking improved. Bringing the sound of nature indoors relaxes the mind and triggers our body’s circadian rhythm, connecting with our overall wellbeing.

Noise can lower productivity as it affects our concentration, productivity, and creativity. As such, open plan offices should also provide choices for different work environments, such as a good mix of private and communal working spaces. In a review of Environmental Psychology, it was found that personal space and privacy could enhance the wellbeing of an individual or community. Privacy is a dynamic process of restricting visual and auditory access of oneself from others. By offering different settings for an individual to choose from, it gives the sense of control of the environment back to the user, which helps to lower anxiety.

A variety of office work spaces comprising collaboration spaces, cluster huddle, and cluster workbenches in an administrative building.

Tackling invisible microbes

Another often-neglected design component is the impact of indoor air quality (IAQ) on health and wellness. The choice of healthy indoor materials is paramount for clean and healthy indoor air. In 1973, NASA scientists discovered over 100 types of volatile organic compounds (VOCs) released by synthetic materials used in its construction within the indoor air of a space station. Inhabitants became ill as a result of inhaling chemicals trapped in its uncirculated air, similar to how occupants experience “sick building syndrome” in conventional buildings with poor air circulation.

Engineered woods and the glue that holds them together contain formaldehyde, which pollutes our indoor air. The toxins released by synthetic materials can be absorbed through inhalation or contact with skin. Designers need to choose healthier material options and explore other design interventions to mitigate this issue.

The use of common house plants to alleviate indoor air pollution was first carried out in the abovementioned NASA research experiment to study how nature purifies and recycles indoor air in an airtight building. Taking a leaf from that, an extensive five-storey high biowall, located at an atrium space at Drexel University, Pennsylvania, showcases a vertical green wall with a diverse array of air-purifying plants organised by watering needs and visual cues. It serves as a living biofilter of indoor air and grows in the absence of soil. Air passes through the biowall via the building’s heating, ventilation, and air-conditioning (HVAC) system, where VOCs are broken down to carbon dioxide and water. The purified air is then recirculated throughout the building via the HVAC system.

A green wall within an interior setting

In Singapore, NUS’ School of Design & Environment 4 uses an innovative hybrid cooling system. This was integrated with the architectural design from the conception stage, with the goal of championing indoor air quality, comfort, and energy efficiency. Its indoor spaces are supplied with 100-percent fresh pre-cooled air with no return air, at higher temperatures and humidity levels than conventionally done. The Covid-19 pandemic has accentuated the importance of non-recirculated air in interior spaces to flush out invisible toxic microbes. As a result of bringing fresh air into the building, a seamless indoor-outdoor space is created for a healthy living environment.

A seamless indoor-outdoor connection is created at NUS School of Design & Environment 4. Surbana Jurong is the full-suite consultant for the project, in collaboration with Serie+Multiply Consultants and Transsolar Klima Engineering. (Photography: SJ Architecture)

“The Covid-19 pandemic has accentuated the importance of non-recirculated air in interior spaces to flush out invisible toxic microbes. As a result of bringing fresh air into the building, a seamless indoor-outdoor space is created for a healthy living environment.”

Designers need to be attuned to environmental psychology and the impact of the built environment on our wellbeing. Ultimately, the challenge in the design of a holistic, biophilic environment in interior spaces is how to transpose this multifaceted, integral experience in nature; using the visible and invisible aspects of design to create immersive, multi-sensorial urban sanctuaries.

This article first appeared in SEEDS Journal, an architectural publication and thought leadership platform by the Surbana Jurong Group.

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