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Nancy Clanton


Lighting designer  

Clanton & Associates 

Boulder, Colorado


Interview by Nick Bleeker and Chere Griffin

Denver Union Station, Denver, Colorado. © Ryan Dravitz Photography
Lighting designer Nancy Clanton
Nancy Clanton, President of Clanton & Associates in Boulder, Colorado, earned an architectural engineering degree with an illumination emphasis at the University of Colorado when lighting design as a career was in its infancy. She recalls that it was a different and valuable approach to engineering education, incorporating how the eye works, and the psychology of light, so that the emphasis was on lighting for people and visibility instead of lighting for numbers.

Why is sustainability and regeneration important to you?

It’s always been important to me, it’s at my core. In the 80s, I was part of the team responsible for greening the White House, along with Francis Rubenstein and Hayden McKay.  That’s also when the public movement towards green gained momentum. As part of that, we knew that daylighting, or first generation light from the sun, was huge. Back in the 30s and 40s and before then, all buildings were day lit; they had the right idea, and we need to bring those buildings back to their initial glory. 

Daylighting and electric lighting are intertwined; one cannot be designed without the other. And now, so much knowledge is coming out about circadian rhythm and the effects of light on our hormones, and our well-being. We’ve known about that for a long time, now it’s narrowing down to exact nanometers, and wouldn’t you know, those same nanometers also contribute to sky glow.

Sustainability is also about our environment; light’s ecological impact is huge. We know that along with sky glow, blue lighting affects animals and insects and plants, so we need to learn from nature and apply it to the way we design. For example, if we’re in a fly zone, don’t uplight a bridge during migration season. Let’s pick up on nature’s clues and use dynamic lighting to respond to them. That’s the ultimate sustainability, working with nature instead of in ignorance of it.

Lighting designers often work with architects, engineers, and others as a team effort.  What is important for these external team members to know when it comes to lighting design?

With a lot of projects, the building comes first; but instead, let’s start from the user and work backwards. Lighting should be for visibility and emotion and acceptance, not just numbers.

Let’s look at important user attributes: qualities like day light equity, where everybody gets daylight, or flexibility equity to adjust your environment, whether it’s thermal or acoustic or lighting. Once that’s nailed down, give us the opportunity to light the architecture or beauty of the space, and then everything else falls into place. Ambient lighting should be separated from personalized lighting. There tends to be too much demand on one type of light to provide ambient lighting and task, or more accurately, personalized lighting; they should be separated. 

Personalized lighting is for you to light interesting things, and you can adjust the level to what you want.  Difficulty in a project arises when there are separate teams for core and shell, and furniture, fixtures and equipment (FF&E) because the lighting doesn’t get integrated. I’d love to see architectural lighting designers drive personal lighting and work with interior designers all the way through so that everyone, the teams, owners and tenants, can see the balance of light and layers of light.

In your presentation, ‘Tale of Four Cities’, you talk about contrast-based criteria in outdoor spaces. Would you please explain this, and why it’s different, and preferable to, uniformity criteria?

Contrast is how we perceive an object against different uniformity or brightness backgrounds. I did a contrast experiment as part of lighting training for the Navy Anti-Terrorism Team. Actually, we tried to break into buildings at night – it was terrifying! But, it was a controlled scenario, and was meant to report on security breakdowns. The highly secure buildings were concrete, with concrete sidewalks, and what color did the team wear? Black, as one would naturally assume. The squad commander and I both wore white or khaki, and no one could see the two of us against all that concrete. 

We’ve found in our studies, including the ‘Tale of Four Cities’, that color has a tremendous effect on contrast, even with people who are chroma-challenged or color blind. We’re not to the point where we have definitive answers yet, but I can tell you that, for example, you can see yellow from anywhere. In fact, it caused problems in one of our experiments because people could see it in the next sequence, ten blocks away. 

We also found that the more non-uniform the lighting, the faster objects were detected; we kept dimming the lights, hoping to jump off that plateau of visibility, but instead we kept skirting across the top, even down to the 25% lighting level. Our research indicated a need to change from vehicular- centric to pedestrian-centric lighting, because the darker the street in a high ambient area, the better people can be seen. 

We could see so much better if we had darker streets and brighter sidewalks. I’m also a firm believer that we should look at semi-cylindrical illuminance instead of vertical or horizontal, at least when it comes to pedestrians and crosswalks. Vertical is too two-dimensional, where semi-cylindrical picks up reflected light coming from different directions. With the new perspective of contrast-based metrics and more empirical data, we can all have a greater understanding.
Denver Union Station, Denver, Colorado. © Ryan Dravitz Photography

Could you please describe a project of yours that stands out in your mind as particularly memorable?

About four years ago, we worked on the interior of the US Green Building Council Headquarters in downtown Washington D.C.  There were a lot of constraints in the project, they couldn’t change their building or add light shelves. So the question was, how can we get daylight in there?  Dean Sanders in our office came up with the idea of using the perimeter walkway, around the walls, as a light shelf, with a light carpet. It worked so well. 

We also added IP addressable controls to lower ambient lighting, and separate ambient lighting from personalized lighting. The watts were calculated to be 0.4 sq.ft., and in reality, they’re running at 0.1 sq. ft. That’s huge. They were a great client to work with, they did surveys and post-occupancy evaluations, and we all learned a lot from that.

What do you envision when it comes to the future of lighting and the intersection of lighting and technology?

Going back to the person and the user, lighting is for them first.  And smart phones and locators will be a huge enabler.  Cars don’t need outdoor lighting as much as pedestrians do, so we need to think pedestrian-centric.  Maybe we can have an app on our phones that work with lighting embedded in the pavement to guide you to a destination or announce where a crosswalk or hazard is, or indicate a change in elevation; that could be good for people with low vision and everybody else. 

Indoors, my dream is to get a blind system that follows the sun. They work with your smart phone to understand where you are in the space and float around the window, not just top-down or bottom-up, to keep direct sun out of your line of vision. The building knows where we are every minute of the day if we keep our phone with us. Let’s use that to really get the most out of the daylight. There’s so much we can do.
Interview published in Luminous Spec Summer 2016

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