The built environment is never neutral. It shapes how people feel, think and act. The challenge is to design with those effects in mind.

Designers have always used elements like light, color, texture and form. This chapter explores how these choices influence our lives.

Dr. Anjan Chatterjee’s research at the Penn Center for Neuroaesthetics identifies three dimensions that account for most of the variability in how people experience space. He calls them the Neuro-Architecture Triad: coherence, fascination and hominess. The Triad applies across every project type HOK designs: airports, courthouses, hospitals, workplaces and more. What changes is how each dimension gets weighted and how it shows up.

Each dimension also looks different depending on the design discipline. HOK’s Experience Design group works closely with interior designers on many of these projects, so the breakdown below reflects both perspectives.

Coherence

Coherence is how easily we “read” a room. When a space is well-organized, we hardly notice it. When it isn’t, we feel it immediately. A coherent space eases cognitive load. An incoherent one can create confusion and stress.

Imagine walking into a space and to the left is a narrow, darker corridor. To the right is a brighter, wider one. Most people will instinctively go right. That’s coherence. Our brains read these spatial cues before we even look for a sign.

In experience design, coherence is delivered through consistent visual hierarchies in signage, wayfinding and graphic systems.

In interiors, it’s intuitive wayfinding through lighting, rhythmic design and the strategic use of mass and scale.

Fascination

Fascination is how complex and informationally rich the experience of the space is. Fascination is what makes people want to explore. It’s the layering of visual depth, texture, pattern and discovery that makes people want to look closer.

Balance matters, though. Chatterjee’s research shows that people on the autism spectrum can experience environments most people find “fascinating” as overwhelming, evoking repulsion rather than attraction. The goal is not for maximum stimulation, but for the right degree of richness.

In experience design, fascination comes from layered visual depth, discovery moments and dynamic content.

In interiors, it means offering different kinds of spaces and design elements, both hyperstimulating and hypostimulating, to support different needs and ways of working.

Hominess

Hominess refers to the degree to which a space creates a sense of psychological safety and belonging. Though this dimension may very well be the most important for designers, Chatterjee says it’s also the one that’s received the least attention. Hominess isn’t about domestic comfort. It’s about whether people feel they belong and can be at ease. A courthouse needs it as much or more than an office.

In experience design, hominess is expressed through cultural narrative, tactile materials and human-scale warmth.

In interiors, it’s about creating prospect and refuge, along with stylization and materiality, and providing the fundamental conditions that help people feel present.

For a deeper exploration of the Triad and what it means for design practice, see our conversation with Dr. Chatterjee in Chapter 5.

To support the goals of the Triad, designers rely on familiar principles and elements of design. Designers already work with these tools. Neuroaesthetics sharpens the question: what does each one do to the people in the space.

The image below maps each tool against the Triad. The descriptions that follow add a ‘what it does to you’ layer—the biological or psychological response each one can trigger.

The Principles

Scale: The elements in a space should relate to human dimensions and to each other in ways that support comfort and use.

Emphasis: Focal points create hierarchy, helping people organize what they see and find their way.

Balance: Visual equilibrium that reconciles opposing forces through symmetrical, asymmetrical or radial arrangement.

Rhythm: Flow created by repeating elements within a sightline, bringing movement and order to a space. In wayfinding, though, people often rely on distinctive moments that break the pattern.

Proportion: The relationship between elements and the people using them. Ceiling height and room proportion strongly affect how a space feels. They also have measurable effects on cognition.

Unity: Cohesiveness created when harmony and variety come together through repeated use of elements such as color, pattern or materiality.

The Elements

Line: Lines define spaces, provide direction and lead the eye through an environment. They can be organic and curved or straight and direct.

Light: Light helps people orient themselves. It regulates the circadian rhythm and shapes mood. By manipulating the distribution of brightness and shadow, designers can influence where people instinctively go.

Color: Color is a signal of intent. Saturated tones feel more stimulating, while muted ones feel more calming. Colors drawn from nature make people more comfortable. Keep in mind that responses to color can vary by age, culture and individual sensitivity.

Texture: Texture adds tactile depth, letting designers heighten or soften the sensory intensity of a space. Mixing textures and materials serves people across the sensitivity spectrum.

Shape: A shape is the external outline of a two-dimensional object that forms a boundary. Shapes can be geometric, organic or abstract. People respond more positively to smooth, curved shapes, which can suggest safety, movement and expression. Sharp angles can create tension. Organic shapes and fractal patterns that echo the natural world seem to elicit the strongest positive responses.

Form: A form encompasses the complete three-dimensional appearance of an object, accounting for depth, width and height.

Space: Space is the volume around, within and between objects. Higher ceilings encourage expansive thinking. Lower ones sharpen focus. In any plan, negative space matters as much as the objects in a room.

Pattern: Nature-inspired patterns tend to be complex and irregular, but we instinctively seek order within them. That’s why we gravitate toward fractal structures—repeating geometric patterns that give complexity a legible shape. But large patterns can confuse people with neurological and sensory processing challenges, as they may read them as barriers or level changes.

Mass: Mass is the visual weight of a shape or form. Designers use it to ground some elements and lighten others, giving certain features more presence in a space.

Additional Considerations

Biophilia: Biophilic design restores some of the connection to the natural world that our bodies need. That connection can be direct, like views of a garden or the sound of water. It can be indirect, like organic curves, natural materials or nature-inspired palettes. Or it can be experiential: think about dynamic light that shifts through the day or a space that offers both shelter and a view.

Soundscape: Sound is the most neglected dimension in the designer’s kit and the one most likely to cause problems when ignored. But silence isn’t the answer because it can be a form of sensory deprivation. In some environments, that can be just as unsettling as noise. Good soundscape design removes the noise that shouldn’t be there and introduce sounds that support what the space is trying to do.

Every material, sightline, ceiling height and decision about what gets heard or muted is a design decision. These aren’t just finishing touches, they’re the design. They determine whether a space supports the people inside or subtly works against them.

The video in Chapter 3 shows what this looks like in practice. Kay Sargent uses real HOK projects to demonstrate how these principles and elements shape the spaces we move through every day.