Why we should design with daylight
Natural light is critical for human health and wellbeing — yet our built environment can keep us in the shadows. We asked Chris Lowe of BDP Lighting why daylight designers should be involved in construction projects from the beginning.
How much light are you getting right now? If you’re in an average office, it’s probably around 500 lux — less than 1% of what you’d get outside when the sun is out. It’s the same in a classroom. As more and more research shows that exposure to daylight makes us healthier, happier, more creative, more productive and smarter — and as free and abundant as it is — it’s odd that we don’t maximise its use inside.
With such little natural light penetration in many of the buildings in which we live, work and learn — our internal environments are little more than biological caves. As architects and construction professionals, we have the power to reverse this — and we can start by engaging lighting designers at project inception.
Chris Lowe is a lighting designer who leads the team at BDP — the architectural powerhouse headquartered in Manchester. Amongst their work is the University of East Anglia’s multi-award-winning Enterprise Centre. Rated as “outstanding” by BREEAM and Passivhaus, it has been described as the greenest commercial building in the UK.
In this interview, Chris tells us about the role of natural light in inspirational, interesting and healthy buildings — and why artificial light alone doesn’t really cut-it.
Q. How integral is lighting design to architectural projects? Are you a rare breed?
Going back 10–15 years we used to be a much smaller profession, but now more and more RFPs (requests for proposal) are requesting lighting designers as a specialist named profession, so we’re gaining traction. I think people now realise they need specialist input on lighting techniques, and how to maximise the benefits of light through exploring design opportunities.
Q. Why is daylight design important?
Light has the ability to transform space, and beyond that, it’s integral to our health. We have evolved so that our hormonal cycles align with astronomical day and night, and chronobiological research shows that light has a huge non-visual impact on our bodies — especially since the rediscovery of the ganglion cell in the 1990s. For example, exposure to daylight suppresses melatonin (the hormone associated with sleep) in the day and allows it to be released at night for a restful sleep.
If people don’t get sufficient light stimulation during the day, it puts them out of sync. On a sunny day outside you might receive 100,000 lux, and on a typical cloudy day in Manchester, maybe 10,000 lux. But inside a school classroom, for instance, you might only receive 300–500 lux — and that’s the biological equivalent of being in a black box. This has a detrimental impact on your biology in ways we are only beginning to understand. The bottom line is that daylight is irreplaceable, and it can’t yet be matched with artificial lighting technology.
Q. Do buildings generally suffer poor daylight design?
Going back a long way, I think daylight was more highly valued. But then we developed mass construction techniques with lots of concrete and deep floor plates, and architects assumed that natural light could be supplemented or replaced with artificial light. It’s taken a long time for people to recognise that it can’t do the same job. People need natural light, views out and higher illuminance levels. Some older technological advances have caused daylight design to suffer — but new ones like reactive façades and skylight systems are bringing about new opportunities.
Q. Is there an ideal lux level for internal environments, or amount of glazing to deliver optimal light penetration?
The ideal amount of light is very subjective. It’s how the light is distributed throughout the space that’s important. There’s no point having 100,000 lux on one patch of floor, and then one lux on another patch and then no light on the ceiling. We use lux levels as they’re one of the few kinds of measures most people understand, but it’s more complex than that. It’s really about how much light is reflected back from surfaces towards the eye, which can shape people’s perception of space. So I won’t say that there is an ideal lux level, but we should be trying to create daytime environments that are lit as closely as possible to that of outside — feasibly-speaking of course, once you’ve taken into account energy and glazing costs and those other things.
Q. How can lighting designers make a difference?
To achieve truly great lighting design, we try to get involved at the earliest stage — it is important to conceive the interior and exterior at the same time. One of the first things we try to do when we meet with architects to discuss buildings is to explain that artificial light, natural light and building form must be designed as one. But it doesn’t have to blow the budget — there are improvements that can be made, no matter what resources are available. It’s important to give proper consideration to daylight, and not just leave it down to a contractor-led design and decision.
Daylight is both a science and an art, but too often we settle for an engineered solution. Daylight integration shouldn’t be seen as a constraint but as an inspiration. This is where lighting designers can help play a part and assist architects to create beautiful spaces which benefit human health.
Chris Lowe is a Lighting Associate at BDP. He is speaking at a number of our Education: Design a Brighter Future breakfast seminars in 2017. You can find out more and sign-up here: velux-event.cpdi.co.uk
For more information about lighting design at BDP, visit: www.bdp.com/lighting