The Bartlett


Transcript: Bright Lights, Big City

Exploring the design of light in spaces, seeking to understand how light can help...and harm. 


light, lighting, Lorna, people, daylight, night, design, Jemima, home, environment, bartlett, wondering, UCL, space, indoors, dark, Christoph, bit, energy, research


Christoph Lindner, Jemima Unwin-Teji, Lorna Flores Villa

Christoph Lindner  00:03

Hello and welcome to Building Better, a podcast about life and research at the Bartlett and how we are trying to build better.

Christoph Lindner  00:15

My name is Christoph Lindner, and as well as being your host for this podcast, I am also the Dean here at the Bartlett. In each episode, I'll be sitting down with other members of this community to explore a topic that captures a snapshot of what happens here. From innovative techniques to interdisciplinary ideas to groundbreaking results.

Theme music  00:38

Christoph Lindner  00:45

This episode is all about light. I want to know about the thought processes behind lighting spaces, and the considerations involved. From wildlife to user your safety to aesthetics. I'm also curious about the future of light, and whether it lies in technology such as smart lighting, and to have this conversation, I'm joined today by Dr. Jemima, Unwin-Teji, and Lorna Flores Villa. Jemima Unwin-Teji is a lecturer in the Bartlett School of Environment, Energy and Resources and program leader for the MSc in Light and Lighting. Jemima's PhD research considered the effect of street lighting on pedestrians and it's evolved to consider the impacts of light on public health, smart cities, and the design of inclusive environments. And my second guest is Lorna Flores Villa, an industrial designer and a PhD researcher at the UCL Institute for Environmental Design and Engineering. And she explores daylight and its impact on sleep quality.

Theme music  01:53

Christoph Lindner  02:00

I want to begin with a question that for both of you will probably sound basic, but for me, and maybe some of our listeners is actually really important. And the question is this, what is light? How should we understand light? Jemima?

Jemima Unwin-Teji  02:14

So light is the visible part of the electromagnetic spectrum from about 380 to 780 nanometers, the physicists would say, you know, it's the electromagnetic spectrum. A lighting designer, seeing the light is what makes things visible and we have various metrics which measure different aspects of light, how much light lands on a surface, how much light reflects off. Light is a life source, you know, without it, we wouldn't be here.

Christoph Lindner  02:41

Well, I love a definition of light that involves both physics and beauty. So it's a great way to describe it and Lorna what about for you? What, what are some of the ways in which you understand light?

Lorna Flores Villa  02:54

Well, I think light is the medium that makes an environment as functional, or that can contribute how the atmosphere feels in space, but also will make the user to have like different ways of how they feel or how they are behaving. So basically, lights just set them with in, in the indoor environment, but also in the outdoors environment. So people will behave differently depending on how light it is falling into the surface or into space.

Christoph Lindner  03:26

So already, we're getting into something, I think, quite complex.

Lorna Flores Villa  03:30


Christoph Lindner  03:30

And you know, Lorna, you're already alluding to the way in which light is not a neutral presence in our lives. And so the the kind of light, the manner in which it's present, can affect our mood can affect our thoughts, can affect our feelings. And I'm just wondering, you know, we tend to have light in and around our lives all the time, and maybe aren't very conscious of it. And so I guess what I'm wondering is, when you study light, what are some of the ways to be aware of its presence aware of how it acts on us?

Jemima Unwin-Teji  04:03

Well, to be honest with good lighting? You don't actually notice it? We're not overly aware of it, because it's just so natural, isn't it? Oh, you know, our body clocks, our biology is tuned into the day-night cycle. You can have a one celled organism in the sea that has a day-night rhythm. So I think it's unconsciously we're tuned into light. Now obviously, when there's a problem, that's when we tend to notice it is that you know, when something's glary or you know, we get, you know, too many downlights and you end up coming out of your office with a headache or something's flickering. So I think the absence of you know, obvious problems is actually a sign of good lighting. I remember someone said to me, if you look in the corner of a... if you have a room that's painted white and you look in the corner, the top corner, and you see those three surfaces, the ceiling and the two walls that join where they touch each other. They're actually all different colors. So that's how how light reveals 3d form and is in incredibly subtle.

Christoph Lindner  05:03

So I'm doing that right now as you speak [laughter] I'm looking up at the corner and seeing whether that works. And indeed, where those three surfaces come together, they are all different shades. And it's taking me back actually to when I used to study painting and having to think about light in those terms. And it sounds to me like, actually, when you study lighting design, there's a physics-scientific dimension to it and there's and then there's a kind of aesthetic, artistic dimension to it. And I'm wondering, how do you bring those two things, those two worlds together, the kind of the painterly, and the scientific?

Jemima Unwin-Teji  05:36

Yeah, so that's obviously the wonderful thing about light is that it is, as you say, it's a creative, the process of deciding on lighting is a creative process. And as a designer, you know, we can influence absolutely, you know, we can we almost you can decide what people see by how you light and how you paint and what colors you choose. So any artist or architect or designer will or tend to have a vision, you have an idea of what you want something to look like. And often it's called the design concept, or, you know, the vision or you know, how you imagined this space is going to be. And then once you have that, that's where the science comes in. Because you know, your client might be saying, oh, you know, I want to have, you know, black walls. You get like a black piece of paper and you know, and shine light on and say, "oh, look, look how low, that's low luminance, it's dark, it doesn't look so dark, it makes the whole - might could make the space look gloomy". So basically, that the science is a tool to justify and explain what you want to do. So I think it's more like a communication, you communicate with the science, and you justify your your art using the numbers.

Christoph Lindner  06:41

Yes, I would imagine that that designing lighting for cinema versus an operating theatre, the specifications are quite different.

Jemima Unwin-Teji  06:49


Christoph Lindner  06:50

And, of course, what's at stake is quite different. But you're talking a little bit about measuring light, and quantifying lights and categorising light. I'm wondering, Lorna, in your research, how do you understand the effect of light on people? So how do you sort of measure and interpret the way light affects individuals or groups of people?

Lorna Flores Villa  07:12

Yeah, well, in my case, because I was interested in sleep quality. So what I did is just ask people about how they're feeling. So it's more about how people are reporting to feel after they have been exposed to the outdoor daylight. So it was kind of tricky. And this is one of the issues that I have encountered with my research, because it's so complicated. And people obviously they are when they are outdoors, they either think they are outdoors, but they are actually inside the building. So they are not exposed to daylight, per se, but they are reporting as they are. But there are, I guess, in the last 10 years, there have been developed some tools for recording how much light people are receiving. And there are some devices that can recall how much light is coming through the eye. So it's more specific, but they're still in development. So they're still testing this so we can understand exactly how much the type of daylight that we are receiving is affecting in terms of health or you know, brain and how this will impact overall in their well being.

Christoph Lindner  08:22

So thank you for mentioning daylight because, and I feel a little bit bad doing this because I want to ask for your help in resolving an argument I keep having at home throughout the pandemic with my family, specifically my children, where I keep saying to them you have to go outside every day, you've got to get some daylight you can't just sit indoors and they try to argue that it doesn't matter what kind of light you get just as long as you get light. And so is it really true that daylight as a kind of light has value and is good for us in a way that artificial light just cannot replicate? Or are there ways, through artificial lighting, to bring all the benefits of daylight into enclosed spaces.

Lorna Flores Villa  09:03

To be honest, I could be a bit biased because I really my research is focused on daylight so I'm trying to bring this up as being important but it is light - daylight cannot yet be mimicked by indoors light. And the reason for this is because the daylight is always changing throughout the day and the wave lengths we receive and the amount of daylight that we receive, you cannot be adjusting that in the indoor environment yet. And they have been trying to do that and they are trying to sell this idea of this smart lighting that can just change colors throughout the day but actually they are not changing how much light we are receiving. So it's kind of two different thing but for me it's and I think for Jemima as well, we think that being exposed to daylight at the right times is always important. Yeah so basically daylight brings some importance in our health and we have to be exposed to it, it's not the same to be indoors with the electric light and be outdoors and receiving the right light at the right time and the right amount of light, if that makes sense.

Jemima Unwin-Teji  10:19

Yes, I completely agree with Lorna so. So we need to get outside, particularly in the morning, I will say for at least I don't know Lorna, times on this,  all you're reading from your PhD, and I think it's at least 20 minutes, half an hour?

Lorna Flores Villa  10:32

Half an hour, yeah.

Jemima Unwin-Teji  10:33

It does a thing called entraining our circadian clock and what that and that's a fancy way of saying our body becomes synchronized with the external pattern, light dark pattern. So we need to get enough bright light to, which is what you can only ever get enough from daylight to be honest, because if you want to do that with electric light, it would be awful, imagine like sitting in a light box. Imagine you can never really mimic daylight. Now the quality that as Lorna said that, you know characteristics, the variation, illuminative change, the CCT - the color temperature is changing. And yes, I would tell your children that they need to get outside for half an hour in the morning at least and ideally more. That's the minimum.

Christoph Lindner  11:16

That's really helpful. I will pass that along.

Theme music  11:18

Christoph Lindner  11:24

So we've talked a bit about the relationship between light and health. I'm also wondering about the relationship between light and safety. Because early on Jemima, you mentioned, you know, people mostly become aware of lighting design when it's not working well. And I think one of the one of the ways in which people often experience bad lighting design is at night in poorly lit situations in spaces, like in a poorly lit street or poorly lit parking area. And I'm wondering if you could talk a bit about the importance of lighting to safety?

Jemima Unwin-Teji  12:01

Yeah, so first few things to mention and one is that there's a difference between actual safety and perceived safety. So we need to differentiate those two topics, so on perceived safety, so reassurance light definitely has an effect, and from what my research showed was that people just don't like dark gaps. So maybe if you have a dark area for too long, and I think it's, you know, people are just... people will rate that street to be less safe at night compared to their day rating. And obviously, we have to do that because you get different areas, which, you know, you have different perceptions. So you need to use the day rating as a control of the night one. Yeah. And I found that yeah, it's basically dark areas for too long, people would significantly rate the streets to be less safe. And I think it's probably and I'm speculating here, but I think it's probably goes back to a primordial fear of what could pop out of the dark, and, you know, jumped out at us. There's a chap, a researcher called Warr, W-A-R-R, who came up with the concept of "lurk lines" it's like, we don't like what we can't see, because we kind of then imagine what could be there. I think that's important to mention. But I also think that and what I found was that lighting always mattered with other things. You know, it was aspects, for example, are other people about? You know, how busiest street is, the reputation of the area, perceived access to help. So if it was somewhere where you felt like someone would come to your aid if you got into trouble. So it's incredibly complex, and very rarely was was lighting a factor on its own, like only lighting it was always lighting in combination with other factors.

Christoph Lindner  13:45

I guess that makes sense. Because you know what, we wouldn't want are cities at night that are lit up like stadiums or something, floodlight everywhere, lights everywhere, and so great. You can't you can't sleep and it's just, you know, invasive and aggressive. And so I think this is where questions of design come in, you know, how do you strike the right balance for there to be enough light to be able to see, to go where you want to go, to feel safe or be safe, but at the same time to kind of respect the fact that it is night. And also there's an interesting, I think intersection here with sustainability in the environment. So if we think about the effect of night lighting and cities on the migration of birds and wildlife and things like that, as well as the energy it takes to run lights, I'm wondering how do you balance all of these things, you know, safety, aesthetics, health, the environment, the energy?

Jemima Unwin-Teji  14:35

Yeah, I mean, I would say on tweets at night, it should be the absolute minimum necessary, shouldn't it? And by following the standards and guidelines, we pretty much get to minimum acceptablity. What I think is really important is also lighting vertical surfaces. So there's a tendency in the Standards to talk about lighting the horizontal surface of the pavement, but I think a bit of light on buildings can help help us with orientation, yayfinding and we get a sense of you know how to navigate particularly unknown and unfamiliar environments. In terms of wildlife, I mean, you can create, for example, dark tunnels for bats, so they can travel around the city, you know, keep to their original roots. And obviously, the the energy use, you really don't want to waste energy. So I think I think you hit the right balance, by you have to just be very, like any good designer, you have to be very responsive to the contexts, don't you? So you've gotta think, okay, who's here? Who needs to see? You get all sorts of interesting contradictions come up, like, you know, say you've got a street where absolutely nobody goes out at night, well, can you really justify lighting a street so that when you look out the window, it was a bit of light? Probably not. But then you have other areas where you have you know, nightshift workers who absolutely, you know, need to have the route home well lit, you know. So yes, I think the answer is just to be very context specific, like any good design.

Christoph Lindner  16:02

So it almost suggests to me that the lighting infrastructure that we have in our communities and in our cities needs to be, to a certain degree, adaptable, because the needs, the activities, the patterns of communities aren't always stable over time, it seems like we need to have flexibility and adaptability designed into some of our infrastructure, or am I being really naive about that?

Lorna Flores Villa   16:25

I just remember when I used to be in Cricklewood, they did some upgrade of lighting of LEDs. And it was extremely bright, and apparently was because there were a lot of crime issues around that area. So they were trying to just put a lot of lights in order just to diminish that. But then when they see like, after a few months, what was happening with it actually didn't make any impact in terms of crime. And actually people living there were complaining, because it was too bright that it was just disturbing the neighborhood. So I don't think just putting a lot of light in some locations will resolve the issues that it has. So there is the need to do proper, in my case, I think it's important to do the proper research to see what's the real issue in a specific location, and see how that will impact overall and if it will work or not. So I think we have to consider this this two issues that Jemima was saying so just context, but not just put in a lot of light in one location just to make make it think that they are doing something but they're actually not tackling the problem.

Christoph Lindner  17:39

So would it be fair to say that in lighting design, there's almost an anthropological or sociological dimension, because you really need to understand people and communities - who they are, what they want, how they operate?

Lorna Flores Villa  17:54

Yeah, I mean, I think it is. And we have to also understand that not everybody will see the same lighting design, as we intended. So a good lighting designer will try to merge into what actually the user needs, instead of what the lighting designer might think is cool to have in that location or or place.

Jemima Unwin-Teji  18:20

Yeah, Lorna raises some really interesting points that one, on this issue of making environments much brighter to try and solve a crime problem, what has happened in previous researches, that reported crime increases post increased lighting installation, because people can actually see what's going on, and then report the crime. Then you have the other issue that say it does have a deterring effect, then there's this thing called displacement where you know, the crime just moved to another area. So it's not actually gone. It's just moved to the next dark street. Yeah, lots of conflicts. I mean, on your point of adaptability and flexibility, I think that's quite interesting. Because now with lighting controls, particularly with LEDs, it's incredibly easy to control lights, so you can dim change the color of the light very, very easily and at the touch of a button, and it's cheap to do, relatively cheap to do, although obviously manufacturers will try and sell that sell that capacities at a nice profit. So I think that can be designed into the system. And yeah, that's that's a good thing. So I think despite the fact that there is a kind of hard infrastructure, once that adaptability in lighting controls are there then then that flexibility is there too. And I think there's another interesting point about Internet of Things, you know that everything being connectable in future. So I think if, for example, the hard landscaping for example, you know, seats and curbs if we started to think about perhaps integrating light there, then we could link that perhaps to the streetlights or even building facades so that the street light becomes a whole you know, planned lighting scheme, but then we have practical issues with ownership, you know, for example, so if the counselor comes in lights, the front of my house I'd be pretty annoyed so, so that then you get the these issues that you have come in which are never easy to solve.

Christoph Lindner  20:20

So we've talked about healthy light, safe light, indoor light, outdoor light, public light, I'd love for us to talk a bit about the future of light. But maybe a way of getting into that is is to touch first on the future of work. So what I mean is that right now, lots and lots of people are working from home, and their home setups have not been designed by employers and not been designed as workspaces. And they're cobbling together furniture, and, you know, internet technology computers, but also light setups in order to function. And I'm wondering what advice you would have for people as they set up their home working environments? What kinds of things should they take on board when it comes to lighting those spaces, and I ask that right now with a giant sort of selfie, one of those weird round selfie light shining in my face, a desk lamp, kind of on the other side, the light on above me and my computer screen glaring in my eyes, and within a couple of hours, I'm gonna have a horrible headache and want to go outside and get some fresh air and some natural light. But I think many of us really have unhealthy impractical setups. So what how can you help us do this better?

Lorna Flores Villa  21:31

Yeah, I mean, I think it's a tricky one, I think people tend to always find a location next to a window. And I have seen it when I have like, some calls, and all that all of the people have their offices next to a window, which I think is a great start. But basically, to have a desk lamp, I think that will be ideal, because we are always working on a device that it has self light. So I don't think we need more light than that we are receiving from the, from the screens. And if we're working next to a window, I think that will be enough if you just work like a normal time from eight to five, I guess.

Jemima Unwin-Teji  22:13

And I completely agree with Lorna on that the daylight is essential. Getting near a window if possible. Also view out you know, we have if we can look out and have a good obviously you can't control your view, but even I think just if you can see the sky, that's a wonderful thing from where you're sitting. So say that that primarily and then then you got to think okay, most of us are now working on laptops and computers, which is a self luminous source so we can increase the screen brightness and we can see what our actual task is lit just by the nature of what we're doing. So actually, what is it we want the light for now? I know those circular lights, I know my husband has one because he basically wants to look good on the camera. If your aim is to look good on camera, then yeah, you do exactly that you have that you know something framing it so it's nice and uniform across your face is as far as possible. Yeah. And if you have you know, like like from one side and then it'll give you more modeling. So example my face now you can you can see, I've got like light source coming from there. So my face is probably looks more 3D than yours Christoph, because you've got you've got one of those round lights, would you say? Kind of deciding on how we want to look in front of the camera. And I also think, yeah, as Lorna said, having a task - I find that having a task light next to me does help me focus. So sometimes you put that on everything else, it really helps me focus on what I'm doing. It's more psychological. Like it helps me concentrate. It's not that I actually need it to see particularly when I'm on my laptop. Yeah. And it's very much a individual preference and choice. And in trying it out. I do think you know, you need a lot of space. In my corner. I'm a little bit squashed in and I'm always like I want like another meter to spread out.

Christoph Lindner  23:56

It's making me think a little bit about how some of my smart devices nudge me around lightning. So there's one thing where your home learns your preferences and what you like, and anticipates that and creates it for you, then there's a question of is that good for you? So my phone, for instance, keeps telling me I need to switch to night mode every night. It keeps telling me to put it down, stop looking at it. It wants to switch you know, it keeps giving me clues that maybe my preferences around light are not necessarily super healthy. And so I'm almost wondering of a version and probably it doesn't appeal to many people but I'm wondering a version of you know, could you have smart AI driven lighting systems that can actually improve our health, improve our sleep and improve the way that we live and work and maybe make us more active and get us out of the house more because of how they nudge us positively to do the healthy behavior?

Jemima Unwin-Teji  24:49

That's ambitious. That would be very, very ambitious. I'm just thinking like now in my home, the lights are off because there's enough daylight and that's the way it should be If I'm honest, if the lights start nudging me to do things that would probably be a bit annoying. I'm not sure I want the lights talking to me, it's like those people who have those Alexas. So yeah, I think AI is, you know, an absolutely, wonderfully powerful tool, but I personally would not want my phone telling me what to do [laughs]

Christoph Lindner  25:23

No, I think I think most most of our audience are with you on that one. We don't want to be on the phone to be our boss. And, Lorna, what are your thoughts on the future of lights, some of the factors that will drive innovation, but also the direction?

Lorna Flores Villa  25:35

Yeah, I mean, I think two years ago, because we didn't have the pandemic and all that, I was thinking that we were going into the right path, because there were some, like the world standards, they were focusing more on the user rather to saving energy. And also, because all of the recommendations that were done, they were based on research. So it was something that somehow it has been tested, and then they think it's the best for the user to be spending time indoors. But now, because we all of us are having different situations in their homes, or if we are going working in the in the office, I'm quite sure that in terms of light, people would always prefer to have control of their environment. So yeah, so either if you are in like in an office environment, if you have a desk lamp, again, you will, you will know when you turn it on and off. And I think that's the sense that we as humans like to have, like the control of things. So yeah, it's like a sensible thing to just keep doing. And maybe overall trying to, let's say, teach people how to what was the best, best way of just controlling the light, I guess.

Jemima Unwin-Teji  26:58

And often that might be switch off the electric light switch.

Lorna Flores Villa  27:02

Yeah, because sometimes they forget, or they like one of the things that we also have found is for the blind, if it's come in a lot of sunlight through it. So people tend to just roll back down the curtains, and then they forget to just put it up and then they just leave it like that. And then the next day, they just keep the electric light on instead of using the light that is coming through the window. So that's the thing that needs to be taught to people just to get into the attitude of look, this is good for you, you have to do this and that or avoid, just look at your phone at midnight or something.

Jemima Unwin-Teji  27:44

So we had so we had an MSc student who looked at groups, so so there it was, so people put in small groups in a room, and the lighting was dim down really slow, really gradually. And then we were looking to see at what point did somebody interviews which the light bulb is because that you can do things subliminally. So you can reduce the electric lighting that in a way that people don't notice and save energy that way. But then obviously there's a threshold below which it becomes too low. So anyway, so in this experiment, there were something like it was a small, you know, so like five, six groups, and every single group had a completely different response to this same experimental condition of the light just gradually being dimmed down. They were given a reading task or something. So they needed the light. I think that's really interesting, I think we've got to understand more actually about human behavior and about how humans interact with each other before we do anything too ambitious and complex.

Christoph Lindner  28:39

And I suppose there's also the other the other parts of that situation is, you know, am I allowed to touch the light control, am I in a space where I'm free and empowered to intervene in things like light or heat or moving furniture, and you know, all that kind of stuff.

Jemima Unwin-Teji  28:55

And that's all linked to expectations, isn't it? So if you go into, so for example, when I now go into Central House office, my office, my old office, I would never expect to be able to change the corridor lighting, it's like, that's not my zone or my ownership. Whereas at home, I would want to touch everything. And with an individual office, if I can't control it, it's annoying. And then if it changes without me touching, it becomes like you wouldn't want you wouldn't go into a hospital and expect to be able to change your lighting except perhaps if you're in a one bed room, but you didn't you know, not in your operating theater, which I mean, that's, that's obvious. So I think you've got to understand people more,

Christoph Lindner  29:31

Understanding people more that is a fantastic note on which to begin to draw our conclusion to an end.

Theme music  29:37

Christoph Lindner  29:43

We've been talking about the future of light. And that theme connects very much to a question that we'd like to ask each of our guests at the end of the episode. And the question is this, looking to the future, what is one thing that you think needs to change so we can build better. What do you think, Lorna?

Lorna Flores Villa  30:02

I think as you my my set just to understand what we actually need and what we actually will make us feel good, like in terms of health and well being and be happy in the place that we are inside.

Jemima Unwin-Teji  30:19

Yeah, yeah. And also, I think, I think a lot of it, I found this in healthcare environment working with end users in healthcare environments is that people just like to be listened to. If you go to an environment, you say, okay, how can we improve the lighting people have so many good ideas about what they need, where and what are the problems and I think just listening is really good listening to end users who use the space.

Christoph Lindner  30:42

So thank you so much to both of my guests. We've heard a lot about lighting and I don't think I'll ever look at the corner of a ceiling in quite the same way again [laughter]

Christoph Lindner  31:00

You have been listening to building Better the Bartlett podcast. This episode was presented by myself Christoph Lindner, produced by UCL with support from the Bartlett Communications Team, and edited by Cerys Bradley.

Christoph Lindner  31:16

It featured music from Blue Dot sessions.

Christoph Lindner  31:19

We were joined today by Dr. Jemima Unwin Teji and Lorna Flores Villa and if you would like to hear more of these podcasts, please subscribe wherever you download your podcasts or visit ucl.ac.uk/bartlett/buildingbetter. And of course, you can follow us @theBartlettUCL.

Christoph Lindner  31:44

This podcast is brought to you by The Bartlett, UCL's Global Faculty of the Built Environment and UCL Minds, bringing together UCL knowledge, insights and expertise through events, digital content, and activities that are open to everyone. We'll see you next month.

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