Lighting for Wellbeing: How to Design Spaces That Support Sleep, Mood and Human Performance
Lighting is one of the most powerful — and often overlooked — tools in shaping how we feel inside buildings.
In this episode of the Green Healthy Places podcast, I spoke with Farah Naser of Tactile Lighting about how lighting design can move beyond aesthetics to actively support human health, circadian rhythms, mood and performance.
What emerged from the conversation is a clear shift in how we should think about light — not just as something we see, but as something that fundamentally regulates our biology.
From Visual Lighting to Biological Lighting
Traditionally, lighting design has focused on visibility and aesthetics — ensuring spaces are bright enough, visually comfortable and visually appealing.
But this is only part of the story.
Lighting is not just a visual influence. It is also biological, hormonal and behavioural. That shift is driven by growing research into circadian rhythms — the internal 24-hour cycle that regulates sleep, energy levels, hormone production and cognitive function.
In practical terms, designing for wellbeing means adopting a holistic lighting strategy that balances:
visual comfort
biological impact
emotional response
Circadian Lighting: Why Blue Light Matters
A key insight from the conversation is the role of light spectrum, particularly blue light.
Research increasingly shows that wavelengths in the blue range can stimulate alertness and suppress melatonin — which is useful during the day, but potentially disruptive at night.
This means that evening lighting should not simply look warm. It should also be carefully specified so that it does not continue to stimulate the body as if it were still daytime.
That is an important distinction. A warm colour temperature does not always guarantee low blue light content. Designers need to understand the spectral power distribution of the light source, rather than relying only on how warm or cool the light appears to the eye.
The Importance of Vertical vs Horizontal Light
One of the more technical — and valuable — insights in the discussion is the role of vertical illuminance.
Most lighting design conversations focus on horizontal light, such as the amount of light falling onto desks, counters or floors. But from a biological perspective, what matters most is often the light reaching the eye.
Vertical illuminance plays a major role in regulating circadian rhythm. That has several implications:
daytime design should maximise useful vertical light exposure
evening design should minimise it
overhead lighting at night can be particularly disruptive
This is especially relevant in environments such as offices, gyms and educational spaces, where lighting is often bright, uniform and heavily overhead.
Designing Contrast Between Day and Night
Rather than trying to replicate daylight artificially in a simplistic way, a better approach is often to create a clear contrast between daytime and nighttime lighting conditions.
That contrast helps reinforce the body’s internal clock.
During the day, this may mean:
higher light intensity
cooler tones where appropriate
stronger vertical illuminance
In the evening, it means:
lower light levels
warmer tones with minimal blue light
reduced vertical exposure
This principle becomes particularly important in buildings where occupants spend long hours indoors and may not receive enough natural variation in light throughout the day.
Practical Challenges in Real Projects
One of the most interesting aspects of the conversation was the tension between productivity and circadian health.
For example, someone training in a gym late at night may want to feel energised. A student studying in the evening may still need focus and alertness. Yet both also need to protect their sleep quality.
This is where lighting design has to become more nuanced.
Possible strategies include:
reducing blue light content while maintaining usable brightness
avoiding direct overhead lighting at night
using task lighting rather than relying only on general illumination
designing layered lighting schemes instead of uniform lighting throughout
The aim is not perfection in every moment, but better management of trade-offs.
Lighting Design Is Always Context-Specific
Lighting for wellbeing is not one-size-fits-all.
Different sectors require different responses. In workplaces, the priority may be clarity, uniformity and glare control. In residential projects, the lighting strategy should align more closely with personal routines, comfort and relaxation. In hospitality and wellness settings, mood and atmosphere often become central.
Context is always key.
That is why early-stage lighting consultancy can add significant value, especially in larger or more complex projects where problems such as glare, poor daylight balance or overlit interiors can quickly become systemic across an entire building.
Designing Mood: Light, Shadow and Atmosphere
One of the most compelling ideas from the conversation was that lighting designers do not only design light — they also design darkness and shadow.
This is where lighting moves beyond technical compliance and into experience.
Rather than flooding every space with even illumination, thoughtful lighting design considers:
contrast
depth
soft versus harsh shadows
spatial hierarchy
emotional tone
This is particularly relevant in spas, hotels, residential interiors and other wellness-oriented environments, where people may not consciously notice the lighting, but will immediately sense when the atmosphere feels calming, restorative or uncomfortable.
The Most Common Mistake: Light Levels at Night
Perhaps the simplest and most widespread problem in modern interiors is that evening light levels are often far too high.
Many homes, hotels, restaurants and other interiors remain brightly lit well into the evening, even though the body needs a gradual reduction in light exposure before sleep.
As a rule of thumb, light levels should begin to drop significantly in the two to three hours before bedtime. Vertical light exposure should be reduced, and overhead lighting should be avoided where possible.
This does not mean every space should become dim and impractical. It means the lighting should support the body’s natural shift toward rest.
Measuring Lighting Performance
Lighting design can be informed by a range of measurable metrics, including:
daylight factor
illuminance levels
glare ratios
uniformity ratios
colour rendering index
These metrics help quantify performance and inform design decisions. But they are only part of the story.
Occupant feedback still matters. People can often feel when lighting is wrong, even if they do not have the technical language to explain why. The strongest lighting design solutions combine scientific rigour with a strong understanding of human experience.
The Future of Lighting in Healthy Buildings
Looking ahead, one of the clearest opportunities lies in integrating lighting design earlier and more strategically within the wider design process.
Lighting should not be treated as a secondary layer added late in the project. It should be part of the discussion from the beginning — alongside architecture, interiors, materials and building systems.
There is also a growing opportunity for lighting design to act as a bridge between architecture and interior design: supporting daylight strategy at the massing stage, then shaping mood, comfort and function once the interior experience is developed.
As the market continues to focus more seriously on health, wellbeing and human performance within buildings, lighting will only become more important.
Final Thoughts
Lighting is no longer just a technical necessity or an aesthetic finishing touch.
It is a core component of healthy building design, influencing sleep quality, mood, focus, emotional wellbeing and long-term health outcomes.
For designers, developers and operators, the message is clear: if we want to create genuinely healthy spaces, lighting needs to be considered from the very beginning.
Listen to the Full Episode
You can listen to the full conversation with Farah Naser on the Green Healthy Places podcast via Spotify and Apple Podcasts.
