SLL Light Lines November/December 2020

The Society of Light and Lighting

LIGHT LINES

VOLUME 13 ISSUE 6 NOVEMBER/DECEMBER 2020

IN A HEALTHY LIGHT The LR&T Symposium

WORK BETTER Rethinking the office

Editorial

November/December 2020

FROM THE EDITOR SECRETARY Brendan Keely FSLL bkeely@cibse.org SLL COORDINATOR Juliet Rennie Tel: 020 8772 3685 jrennie@cibse.org EDITOR Jill Entwistle jillentwistle@yahoo.com COMMUNICATIONS COMMITTEE: Linda Salamoun MSLL (chair) Iain Carlile FSLL Jill Entwistle Chris Fordham MSLL Rebecca Hodge Eliot Horsman MSLL Stewart Langdown FSLL Rory Marples MSLL Bruce Weil Gethyn Williams All contributions are the responsibility of the author, and do not necessarily reflect the views of the society. All contributions are personal, except where attributed to an organisation represented by the author.

COPY DATE FOR LL1 2021 IS 9 NOVEMBER PUBLISHED BY The Society of Light and Lighting 222 Balham High Road London SW12 9BS www.sll.org.uk ISSN 2632-2838 © 2020 THE SOCIETY OF LIGHT AND LIGHTING The Society of Light and Lighting is part of the Chartered Institution of Building Services Engineers, 222 Balham High Road, London SW12 9BS. Charity registration no 278104

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Reflecting a general preoccupation in lighting at the moment, this issue is permeated with the theme of health and wellbeing. It is, of course, the focus of the Lighting Research and Technology Symposium which the SLL is hosting online this month.

That there is a relationship between lighting and health – whether physiological or psychological, visual or nonvisual, natural or electric – is beyond dispute. After that it becomes rather more complicated.

As has been discussed before in these pages, in Rumsfeld terms we are dealing with both known unknowns and unknown unknowns but this has not stopped categorical statements being made and specific 'circadian' solutions being marketed.

This state of affairs has caused anxiety among lighting designers and manufacturers, says the SLL, because both groups are concerned that 'the

claimed benefits may not be evident in practice, or worse, they may be detrimental to human health'.

Both Peter Raynham and John Mardaljevic, symposium speakers examining how electric and natural light solutions for health can be implemented (see p5), point out the difficulty of establishing a starting point.

'To provide the electric lighting necessary to support human health we must first understand which bits of health we can support and what sort of level of proof we need to make a health claim,' says Raynham.

JILL ENTWISTLE JILLENTWISTLE @YAHOO.COM

CURRENT SLL LIGHTING GUIDES SLL Lighting Guide 0: Introduction to Light and Lighting (2017) SLL Lighting Guide 1: The Industrial Environment (2018) SLL Lighting Guide 2: Lighting for Healthcare Premises (2019) SLL Lighting Guide 4: Sports (2006) SLL Lighting Guide 5: Lighting for Education (2011) SLL Lighting Guide 6: The Exterior Environment (2016) SLL Lighting Guide 7: Office Lighting (2015) SLL Lighting Guide 8: Lighting for Museums and Galleries (2015) SLL Lighting Guide 9: Lighting for Communal Residential Buildings (2013) SLL Lighting Guide 10: Daylighting – a guide for designers (2014) SLL Lighting Guide 11: Surface Reflectance and Colour (2001) SLL Lighting Guide 12: Emergency Lighting Design Guide (2015) SLL Lighting Guide 13: Places of Worship (2018) SLL Lighting Guide 14: Control of Electric Lighting (2016) SLL Lighting Guide 15: Transport Buildings (2017) SLL Lighting Guide 16: Lighting for Stairs (2017) SLL Lighting Guide 17: Lighting for Retail Premises (2018) SLL Lighting Guide 18: Lighting for Licensed Premises (2018) SLL Lighting Guide 19: Lighting for Extreme Conditions (2019) Guide to Limiting Obtrusive Light (2012) Code for Lighting (2012) Commissioning Code L (2018) SLL Lighting Handbook (2018)

sll.org.uk

Secretary’s column/Contents

November/December 2020

Contents

FROM THE SECRETARY

Twitter: @sll100

• For full programme and

bookings for the LR&T Symposium: www.cibse.org/ society-of-light-and-lightingsll/sll-events/applying-lightfor-human-health • For SLL webinars and online presentations: www.cibse.org/society-of-lightand-lighting-sll/sll-events • For LUXLive 2020 Digital Festival: https://luxlive.co.uk/ luxlive-programme-2020

for Facilities Management guide, as well as the updated and rewritten LG08: Lighting for Museums and Art Galleries. We thank Sophie Parry and Mark Sutton-Vane respectively for authoring the new publications. We will let you know as soon as they are available. Our series of online presentations continues, for the latest programme please head to the website (see above).

The LUXLive 2020 Digital Festival is nearly upon us including the final of SLL Young Lighter 2020 (see p4). Many of the speakers are SLL members and we look forward to seeing their online presentations. The event takes place on 11-12 November. Good luck also to the SLL members who have entered the Lux Awards which takes place on the evening of 12 November where the winner of SLL Young Lighter will also be announced.

CIBSE Build2Perform will take place online on 24-25 November. We will have a number of SLL members presenting during the conference and we hope that you can join us.

BRENDAN KEELY

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EDITORIAL

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SECRETARY’S COLUMN

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NEWS

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HUMAN LIGHTS The LR&T Symposium this month will focus on the theme of lighting and health. Based on their presentations, John Mardaljevic and Peter Raynham examine the roles of natural light and electric lighting respectively

11 WORKING MODEL It is time to rethink the office – how it is lit and how we buy it, says Bob Bohannon

13 WELL CONNECTED Interior designer and health coach Kaye Preston and lighting designer Kael Gillam explain the aims of Designers Mind

15 SPANNING THE CENTURIES Two SLL presidents, past and present, unite to create the new lighting for the historic Iron Bridge

15 NATURAL SELECTION Iain Carlile focuses on three recently published LR&T papers which examine different aspects of sunlight and daylight

16 EVENTS COVER: Spa sphere pool at Euphoria Retreat, Mystras, Greece, lighting by ASlight, winner of an IESNA Excellence Award 2020

BKEELY @CIBSE.ORG

‘This first SLL guidance for facilities managers will reflect their remit in covering a wide range of lighting issues’

© Margarita Nikitaki

If you haven’t managed to book a place at the SLL Lighting Research and Technology Symposium: Applying Light for Human Health you may just have time. The symposium will take place on each day from 2-6 November from 1pm-2.30pm.

The bumper line-up of topics and speakers will include Russell Foster, professor of circadian neuroscience and head of the Department of Ophthalmology, University of Oxford, who will look at How Light Exposure Affects Human Health.

Giving two presentations is Mariana Figueiro, director of the new Center for Healthy Ageing at the Institute for Health, and chief of the new Division of Sleep and Circadian Medicine in the Robert Wood Johnson Medical School at Rutgers Institute for Health. She will be looking at Lighting for Day Work and Schools, and also Lighting for People with Dementia.

Arne Lowden, sleep and stress researcher at Stockholm University, will be presenting on Lighting for Nightshift Work, while Luc Schlangen, senior researcher, and principal scientist and programme manager for light and health at Eindhoven University of Technology, will focus on Lighting for Homes.

In back-to-back presentations, John Mardaljevic, professor of building daylight modelling at Loughborough University, and Peter Raynham, professor of the lit environment at UCL Institute for Environmental Design and Engineering, will consider respectively how natural and electric lighting for human health can be implemented (see p5).

Finally, John O'Hagan of Public Health England will discuss the Future of Lighting and Health. All sessions will be followed by a live Q&A, the final one featuring all speakers from the combined sessions.

The member rate for all five sessions is £40, and the non-member rate £80.

Should you wish to book on to a single session then the member rate is £15 and non-member rate £30. Students can attend all sessions for £20 or a single session for £5.

We look forward to providing more knowledge this autumn with the brand new Lighting

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News

November/December 2020

THE LATEST NEWS AND STORIES

CAPITAL GAIN

FROM SOLAR LANTERNS TO FUTURE LASER SYSTEM: SLL YOUNG LIGHTER 2020 FINALISTS ANNOUNCED Four finalists have been selected for this year's SLL Young Lighter 2020 competition. The subjects of their presentations will range from solar lanterns in Africa to a laser system for the future.

Aleix Llenas (pictured bottom far left), an R&D engineer at Ledmotive Technologies, will be examining spectrally tunable lighting, featuring a UK case study in tracking human behaviour, and the implications for future technology.

Aluwaine Manyonga (second from left) of Emmanuel Consulting Engineers, Zimbabwe, will look at offgrid solar lighting, specifically the Chigubhu lantern, Africa's 'education system game changer'.

A lighting designer at WSP, Giorgia Ross's (far right) presentation will focus on a laser lighting system for the future, while Dipali Shirsat (second from right), a lighting designer for Neolight Global in Dubai, looks at redefining the image of a city with an examination of lighting for disabled spaces.

The finalists will each deliver a presentation. As well as gaining the accolade of SLL Young Lighter 2020, the winner will receive £1000.

The SLL Young Lighter final will form part of the LUXLive 2020 Digital Festival on 11-12 November. The winner will be announced at the Lux Awards on 12 November

A new research project, Lighting London, will explore how councils, developers and landlords can make the capital’s streets and public spaces 'more inviting and interesting at night, while reducing the city’s carbon footprint'. Run by Centre for London, it will build on the Illuminated River project lighting a series of Thames bridges, the City of London’s lighting strategy, as well as recommendations from City Hall’s Night-Time Commission.

'For the most part, city authorities have historically taken a narrowly utilitarian approach, looking to lighting to make roads and streets brighter, but with little thought for creative or environmental dimensions of light,' says Centre for London. The final report, published this winter, will make recommendations to help City Hall, London’s boroughs, developers and building owners to create a stronger and more coordinated citywide approach to lighting, and better light their buildings and spaces.

The project advisory group that will help to steer research will include Mark Major of Speirs and Major.

GLA ADVISES ON UV

ON THE LIGHTER SIDE...

Not sure why squids have cropped up again but there we are. Thanks to a species called Doryteuthis opalescens and its ability to turn invisible, scientists at the University of California, Irvine, have managed to recreate the effect in human cells for the first time, creating tuneable transparency.

Using reflective cells called leucophores that change how light scatters off them enables the squid to change colour or appear transparent. The scientists genetically engineered human embryonic kidney cells to express reflectin, and the

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proteins were seen to gather into particles inside the cells, altering how they scattered light.

Sadly the application is likely to be military, camouflage materials, rather than the more exciting prospect of an invisibility cloak. www.nature.com/articles/ s41467-020-16151-6

The Global Lighting Association has published a guide to ultraviolet disinfection lighting.

Germicidal UV-C Irradiation: Sources, Products and Applications provides an overview of the subject including air disinfection, open controlled access locations, partially open upper-air disinfection luminaires, closed HVAC systems and water disinfection.

Appendices cover the performance of various UV light sources as well as standards and regulations relevant to UV-C devices in selected countries and regions.

The document is the second in a series of GLA publications on germicidal UV-C irradiation. The first, released in May 2020, provides safety guidelines for UV-C devices pending production of international standards.

Both GLA publications may be downloaded from the library section at www.globallightingassociation.org

sll.org.uk

November/December 2020

LR&T Symposium

Zurich Innovation Center of Givaudan, lighting by Lightsphere/Filipa Peixeiro

JOHN MARDALJEVIC: HOW CAN NATURAL LIGHTING NECESSARY FOR HUMAN HEALTH BE IMPLEMENTED?

HUMAN LIGHTS The Lighting Research and Technology Symposium this month will focus on the theme of lighting and human health. Based on their presentations, John Mardaljevic and Peter Raynham examine the roles of natural light and electric lighting respectively Twitter: @sll100

Let’s begin by imagining that we know just how much ‘natural lighting’ (daylight) is necessary for human health – of course, we don’t, but let’s pretend for now that we do. Just how much is likely to be some absolute measure of (daylight) illumination received at the eye. It will be an amount, or perhaps a varying amount over time (sometimes called a profile). Whatever the amount, or profile, it probably won’t be of the common or garden lux variety; rather, it’ll be one of the (now several) non-image forming light metrics. That’s another way of saying that the spectral character of the illumination needs to be accounted for.

Maybe the changes in the spectral character of daylight need to be tracked also, in order to properly effect circadian lighting.

At this point, you might be thinking: 'Hold on a moment, isn’t daylight "circadian" to begin with?' You would, of course, be quite correct. In fact, it would be perfectly reasonable to call for a halt in this progression of reasoning much earlier on. And, instead, begin to ask rather more fundamental questions, for which we need answers before we can even begin to progress meaningfully with any of the above.

Although not explicitly indicated, the title refers to natural illumination inside buildings. As long as we spend moderate amounts of time outdoors, we probably don’t have to worry about getting too little natural light. Unless our intention is to synthesise vitamin D from exposure to sunlight — but (mercifully) that is outside the scope of this short article. Prepandemic, we were probably all spending far too great a proportion of our waking lives indoors. For many, the ‘lockdown’ may have afforded the opportunity to take daytime walks that, under normalcy, would not have happened. It’s also likely that many swapped a dingy spot in a deep-plan office for a better-daylit home alternative (even if what they sit on in the kitchen isn’t quite as comfy as the expensive ergonomic chair which their lower-back has fond memories of). Whichever way, pre-, during or (fingerscrossed) post-pandemic, it is the daylight inside buildings that is important to us.

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LR&T Symposium

‘Planning guidelines in particular can be a major determinant of the daylighting potential of the final building’ Thus we look to guidelines, recommendations and/or standards to ensure that the buildings which we occupy provide the natural illumination that we need. Or, from a buyer’s perspective, ‘want’ rather than ‘need’. The 2012 Future Homes Commission survey showed that '63 per cent [of potential UK house-buyers] rated natural light as the most important aspect of a home'. A need that many (in the UK at least) feel is not being met by much of the modern housing stock on the market.

And so many of us choose to buy energyinefficient Victorian homes that possess, among other things, splendid daylighting from large windows. We cannot, alas, choose either our workplaces or the schools our children go to based primarily on their perceived daylighting properties.

Instead, we must rely on guidelines, standards and so on to provide for that.

 View of sky and ground across a window aperture

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November/December 2020

Planning guidelines in particular can be a major determinant of the daylighting potential of the final building.

In the 1920s, Percy Waldram determined what was intended to be a precise and objective measure of an 'ordinary notion' of sufficiency for daylight illumination. Instead of using the actual (absolute) measures of illumination – as recorded by the instruments Waldram used in the study – he instead defined the provision of daylight in terms of a relative measure called the sky factor (assuming a uniform luminance sky). The daylight factor is essentially an evolution of the sky factor, though accounting for reflected light, glazing transmission and based on the CIE standard overcast sky luminance pattern (codified by the CIE in 1955). In the mid-1990s, climate-based daylight modelling (CBDM) was first demonstrated and proven to be capable of high accuracy, in other words the Four-Component method was validated using the BRE-IDMP dataset. CBDM is now a commonplace simulation tool to predict performance measures for the evaluation of building designs.

CBDM would appear to open the door to being able to predict just how much light arrives at the eye, and when. However, all building performance simulation (BPS) is subject to the performance gap (PG) where the disparity between, say, predicted and actual energy use could be large, for example, a factor of two or more. The magnitude of the energy performance gap is well documented because, once the building has been occupied, the meters reveal actual consumption against which prediction can be compared.

Despite the disparities between simulated and actual performance, BPS is still carried out on a routine basis to evaluate building design options because it is generally believed that BPS will help drive the design in the right direction. While the (possibly illusory) absolute target might be the end goal, it is largely the relative outcomes between design options that drive building design. Illumination quantities, however, are never routinely measured, except for conservation purposes in museums and so on. So the performance gap between, say, climate-based daylight predictions and actual daylight levels in real, occupied buildings has never been quantified. Nevertheless, as noted, validation studies provide confidence that BPS is effective for design refinement/optimisation even if absolute accuracy is elusive.

For the reasons given above, it would be unwise to prescribe any performancebased daylight metrics as a basis for planning, since decisions could be readily challenged in court as ‘unsound’ because of the (unknowable) performance gap.

Perhaps, for planning, we need to take a step back from complex BPS and reconsider some of the fundamental principles of daylighting.

First and foremost: what is the skylight and sunlight potential of the building apertures? This consideration should take place at the early design stage using only a 3D model of the building envelope, but including whatever geometrical complexity is necessary to obtain a reliable result, for example, window reveals, overhangs, balconies, external obstructions. Ideally, the underlying method(s) used to determine measures of skylight/sunlight potential should be purely geometrical, and therefore not subject to the performance gap. Notwithstanding this requirement, it should be possible to then make reliable estimations of the daylighting performance potential of the apertures.

This radical shift in the way we evaluate building apertures is, I believe, needed because the intrinsic uncertainties in BPS are being overlooked in the rush to sate an appetite for ever more impressive-sounding claims regarding the prediction of metrics for non-image forming effects, wellbeing and so on. We need to give the ‘head’ a chance to catch-up with the fast moving ‘feet’.

John Mardaljevic is professor of building daylight modelling at Loughborough University

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LR&T Symposium

November/December 2020

© Chuck Choi

 Autodesk, Boston, lighting by Lam Partners: European workplace guidance due out next year will include advice and suggest possible metrics for mean room surface exitance, together with visual lightness and interest

PETER RAYNHAM: HOW CAN ELECTRIC LIGHTING NECESSARY FOR HUMAN HEALTH BE IMPLEMENTED? To provide the electric lighting necessary to support human health we must first understand which bits of health we can support and what sort of level of proof we need to make a health claim. The two main ways of collecting evidence for a claimed health benefit are double blind trials and large epidemiological studies. In the area of lighting both these methods are virtually impossible so it is going to be very hard to claim a health benefit for lighting in a rigorous way. However, we all know that good lighting in a room can make you feel better, but this is a feeling and so may be described as an improvement in wellbeing rather than a direct health benefit.

On the other side of the coin we know that inferior lighting that perhaps causes glare or is annoying due to flicker can be bad for us and cause headaches. Also there are claims that insufficient illuminance for

Twitter: @sll100

a given task can cause myopia in children.

So perhaps the first thing for electric lighting to do is to avoid these problems by following the existing codes and guidance.

There are two potential ways for lighting to make us feel better: one route could be described as psychological and the other route is physiological. This distinction is somewhat tenuous like the way glare is split into discomfort and disability flavours. The physiological impact of light has been studied a great deal recently, and the mechanisms and pathways involved are documented if not fully understood. However, work on the physiological areas of the problem has detracted from the more traditional studies of the psychological impact of light and, more widely, the whole discipline of environmental psychology is being squeezed out in the focus on neuroscience.

However, psychological benefits of good lighting are there. The problem is pinning down which bit of the lit environment generates the benefits. So again the

problem needs to be approached from the negative perspective. If a room looks gloomy and the people in it do not think there is adequate illumination then there is not going to be any psychological uplift associated with the light. This brings in the concept of Perceived Adequacy of Illumination (PAI). This concept was used

by Kit Cuttle in his paper Towards the Third Stage of the Lighting Profession.

In that paper Cuttle also introduced the metric mean room surface exitance (MRSE). This metric is useful but applying it in certain situations can be hard so a parallel metric of mean indirect cubic illuminance (MICI) has also been developed.

Researchers such as James Duff and Longyu Guan have tested the relationship between the two metrics and found that MRSE is a very good predictor of PAI. This leads to the very good question, why are MRSE and PAI related? As first approximation you would expect the total amount of light arriving at a person’s eye to be a predictor of how light they perceived

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LR&T Symposium

November/December 2020

 Schroders HQ, London, lighting by GIA Equation: 'we all know that good lighting in a room can make you feel better, but this is a feeling and so may be described as an improvement in wellbeing rather than a direct health benefit'

© Hufton + Crow

perceived adequacy of illumination we can then move on to a consideration of elements that make us feel even better. This could be the use of biophilic elements such as green walls or just a nice view from a window.

However, adding extra elements to a space where the illumination is considered not to be adequate is not likely to improve things.

Returning to the physiological impacts of light then the key one we all think of is circadian entrainment. Most people are able to maintain their entrainment by a short period outside during the course of the day.

For these people the physiological benefits of an enhanced electric light regime are somewhat limited. So it is mainly people who cannot get outside, such as people in care, that can benefit from more light indoors. However, the evidence base for any spatial metric of light is very limited and the use of spectrally weighted corneal irradiance almost certainly wrong. It may well be a solid angle weighted log of radiance function that is needed. However, this is speculation.

a space to be. So perhaps it might be worth speculating about what is happening. If you think about what is driving a visual response then the obvious answer is your retina.

So retinal illuminance is likely to be key to eliciting a given assessment of the adequacy of illuminance. Moreover, it is common for the retina and the front end of the visual system to respond in a logarithmic way.

It is also likely that our assessment of illuminance adequacy is related to some form of summation of the input received across the retina. So the total stimulus is going to be related to the sum of the logs of the retinal illuminance on a given area multiplied by the given area.

Retinal illuminance is a function of luminance in the field of view and the size of the pupil, and the retinal area illuminated is a function of the solid angle subtended at the eye by the source. If you sum the logs of the source luminances multiplied by the associated solid angles for a range of situations you

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find that your result tends to follow MRSE. This is perhaps why MRSE is a predictor of PAI, but this is just a supposition.

If we think about the physiological responses to light then the same argument may well apply so perhaps we need to do some serious testing of spatial response functions.

The one clear element is that ambient light in whatever form you assess it is important and should be promoted in lighting design.

While it might not yet be the time to write it into normative parts of standards and guides, it is going to be an informative part of the next edition of EN12464-1, the European Standard for lighting in indoor workplaces.

The document, due to come out next year, provides advice and suggests possible metrics including: illuminance on the walls and ceilings, mean ambient illuminance and mean room surface exitance, together with visual lightness and interest.

Once we have design rules that can help achieve

‘The one clear element is that ambient light in whatever form you assess it is important and should be promoted in lighting design’

Peter Raynham is professor of the lit environment, UCL Institute for Environmental Design and Engineering

The sessions at the LR&T Symposium featuring John Mardaljevic and Peter Raynham will be on Thursday 5 November, starting at 1pm

sll.org.uk

LR&T Symposium

November/December 2020

APPLYING LIGHT FOR HUMAN HEALTH: PROGRAMME ollowing the cancellation of the Lighting Research and Technology Symposium in June, the SLL is hosting an online version this month. With the theme Applying Light for Human Health, it will run every day from 2-6 November, and will feature 90-minute sessions on each of the five days.

The thinking behind the theme of the symposium is to help define the parameters for the ways in which lighting can contribute to health and wellbeing, according to the SLL. Following the discovery of the intrinsically photosensitive retinal ganglion cells (ipRGC) in the human retina there has been a great deal of research on the non-visual effects of light. While this effort has resulted in an increase in understanding it has also produced several claims for lighting systems that will enhance human health, says the SLL. This has caused anxiety among lighting designers and manufacturers, according to the SLL, giving rise to concern that 'the claimed benefits may not be evident in practice, or worse, they may be detrimental to human health. Alternatively, if true, hesitation to embrace new applications may see them being left behind.'

Instrumental in planning the 2020 Symposium has been former LR&T editor in chief, Dr Peter Boyce. 'The aim of this symposium is to transfer knowledge from the laboratory to the field. The hope is that this will enable lighting to safely and successfully expand its contribution to human health.'

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Twitter: @sll100

MONDAY 2 NOVEMBER

WEDNESDAY 4 NOVEMBER

1PM-2.30PM

1PM-2.30PM

1 How Light Exposure Affects Human Health: Russell Foster, professor of circadian neuroscience and head of the Department of Opthalmology, Oxford University (30 mins) 2 What Manufacturers Need to Know: Peter Thorns, head of Strategic Lighting Applications, Thorn Lighting (15 mins) 3 What Lighting Designers Need to Know: Florence Lam, Arup Fellow and global lighting design leader (15 mins) 4 Live Q&A

9 Lighting for Sleep: Mark Rea, professor of architecture and cognitive sciences LRC, Rensselaer Polytechnic Institute (20 mins) 10 Lighting Instability, Headaches and Migraines: Arnold Wilkins, emeritus professor at Essex University (20 mins) 11 Lighting for People with Dementia: Mariana Figueiro (20 mins) 12 Live Q&A

TUESDAY 3 NOVEMBER 1PM-2.30PM 5 Lighting for Day Work and Schools: Mariana Figueiro, director of Center for Healthy Ageing, Institute for Health, chief of Division of Sleep and Circadian Medicine, Robert Wood Johnson Medical School, Rutgers Institute for Health (20 mins) 6 Nightshift Work: Arne Lowden, sleep and stress researcher, Stockholm University (20 mins) 7 Lighting for Homes: Luc Schlangen, senior researcher, director of global standardisation, principal scientist and programme manager for light and health, Eindhoven University of Technology (20 mins) 8 Live Q&A For more information contact sll@cibse.org

THURSDAY 5 NOVEMBER 1PM-2.30PM 13 How can natural lighting necessary for human health be implemented?: John Mardaljevic, professor of building daylight modelling at Loughborough University (30 mins) 14 How can electric lighting necessary for human health be implemented?: Peter Raynham, professor of the lit environment, UCL Institute for Environmental Design and Engineering (30 mins) 15 Live Q&A

FRIDAY 6 NOVEMBER 1PM-2.30PM 16 The Future of Lighting and Health: John O’Hagan, Public Health England, visiting professor in laser and optical radiation safety at Loughborough University, vice-president standards, CIE (30 mins) 17 Live Q&A with speakers from all sessions

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Workplace lighting

November/December 2020

WORKING MODEL It is time to rethink the office – how it is lit and how we buy it, says Bob Bohannon any reading this article will be working from home, proof positive of humankind’s innate ability to rapidly adapt to changing circumstances – in this case the risks of Coronavirus transmission. The economic shock from lockdown has prompted the need to stimulate the economy. However, rather than seek to merely regain ‘business as usual’, the call has been to Build Back Better – restabilising our future economy on much more sustainable lines.

The office is changing: sustainability is more important to the investment decision and this is increasingly reflected in the Global Real Estate Sustainability Benchmark (GRESB) rating, tenant decisions and the need for corporate social responsibility.

The government has adopted a target of 2050 to reach net zero carbon emissions.

The popularity of working from home, the time (and C02) saved from not commuting will have large impacts on office use and office design. It is widely thought that many offices will becomes hubs and meeting zones, places where the crucial networking and organisation culture are experienced, but with much work done from home.

The government is calling for a doubling of resource productivity by the year 2050. This requires changes in luminaire construction (for example, replaceable drivers to ensure extended service life and reusable bodies), but also changes in procurement and application.

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compact fluorescent lamp alternative had its drawbacks, but now everybody’s go-to technology is the LED. However, we still regularly accept a similarly questionable standard practice in our office procurement – the CAT A fit-out.

In the UK, a very large proportion of offices are speculative developments, built before the end occupant is either identified or consulted on their needs. Some in the development and real estate sectors consider that in order to let the building, every office floor must be fully fitted out with ceilings and lighting – known as the CAT A fit-out. If you do not know the client, what they do or where they will sit, then the lighting design becomes dangerously simple – light everything, a blanket 400 lux wall-to-wall, corner to corner, so that the bin in the corner gets the same amount of light as a prime desk top.

The �carpet bombing’ approach was sold as being energy efficient, and indeed lighting has been well in advance of many building services in terms of energy efficiency improvements. With the migration to LED over the past five to 10 years, lighting has focused on output efficiency (the energy efficacy of the luminaire itself), in other words a product-led strategy.

The improvements in luminaire efficacy are now suffering diminishing returns while scheme quality has been compromised. The resultant schemes are bland, boring and unpopular.

The problem arises when the tenant moves in and not unreasonably wishes to arrange the space according to their own organisational objectives. The result is that very often a new and almost unused lighting scheme is thrown straight in the skip, with the likely destination of the near-new light fittings being the shredder for raw material recycling. If they do not rearrange the lighting, but do install acoustic partitions or cellular offices the occupier will quickly find that some areas fall below British Standards or SLL minima – employers are now at risk.

CAT A was conceived at a time when there was not the widespread investor interest in sustainability, energy and carbon metrics that we have today. The CAT A paradigm can, indeed must, now itself be consigned to the skip and revisited to better align with current regulatory, sustainability and investment requirements.

 C omcast Technology Center, Philadelphia, lighting by Tillotson Design Associates: future schemes must combine lighting for sustainability and people

THE PAST IS ANOTHER COUNTRY When we look back it often surprises us what poor building performance figures we accepted, the obvious example being the tungsten light bulb with its abysmal energy efficiency. The low energy

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sll.org.uk

Workplace lighting

November/December 2020

DESIGN-LED FUTURE Ellen MacArthur broke the world record for the fastest solo circumnavigation of the globe in 2005. Her bravery and talent to overcome the challenges are a given, but the journey gave her an insight. All the supplies to successfully complete a roundthe-world sailing race were loaded on to her boat before setting sail – there would be no opportunity to gain more resources after that, they would just have to be used wisely. Her insight was that our planet is the same: our resources are limited. She went on to launch the influential Ellen MacArthur foundation in 2010 promoting the progression to a circular economy.

The logical way to release further energy savings is to move to a delivery efficiency focus, in other words a design-led approach where target task light levels are focused on the desk, with visual comfort guaranteed by pro-rata lighting of the floor, walls and ceiling.

Purpose-designed schemes lend themselves to correctly zoned and commissioned control systems, ensuring that the lighting is only on when and where needed.

A net zero carbon building is a highly energy efficient building that is fully powered by on-site and/or off-site renewable energy sources and offsets. Unpacking the first half of that definition, the lighting system must minimise carbon in both construction, operation and whole-life cycle.

Carbon is emitted, and energy and raw material resources are embodied into a light fitting at manufacture, delivery and installation. Following the principles of the circular economy, this embodied energy and resources can be used more efficiently by lengthening the useful operating life of the fitting – short working lives have the opposite effect.

SUSTAINABLE PROCUREMENT THAT WORKS End clients are calling for a net zero ‘label’ for their investments and nobody is investing in non-green schemes, but many are not yet ready to embrace what true net zero actually builds out as and there will likely be resistance. We must therefore offer practical ways to build that better future, which fit with the corporate objectives of all stakeholders in the building supply chain.

The guidance below

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suggests how the developer can move further towards net zero carbon buildings and be cost neutral while delivering a higher quality space, all the time observing circular economy principles, reducing waste and improving sustainability. If we do fewer CAT A fit-outs we’ll achieve more of these things.

The GRESB comments '… forwardthinking organisations identify the linear economy as a risk to their bottom line and as such are changing their business models to reduce exposure by adopting [Circular Economy] CE principles. However, it is a challenge to remain competitive when faced with prevailing economic structures, regulation and standards serving short-term linear business models.'

The following attempts to meet that challenge, working within the industry’s commercial interests while delivering improvements in low carbon performance, circular economy compliance and waste reduction, and comfortable and effective office lighting: 1 Minimise any barriers to letting – build out a show floor with finished zones displaying different lighting and ceiling options. The rest of the building is core and floor, the capital expenditure saved from the CAT A scheme is held in an escrow ‘pot’ and is offered back to tenants to create their fit-for-purpose ceiling/lighting scheme.

2 Developer win – they deliver client choice and can be demonstrably greener when letting.

3 Contractor win – the tenant scheme could still be delivered by the main/ electrical contractor so no work is lost, plus the potential exists to upsell.

4 Agent win – while the agent still has the show floor to demonstrate a lit space, they can also now let and sell spaces that are more environmentally responsible and potentially more aligned to the WELL standard, which many clients are now asking for.

5 Tenant win – they gain a purposedesigned scheme to suit their organisation.

6 End user win – the lighting for their task is designed for them and their task, so it will be more suited to their job and will typically be healthier.

7 Planet win – no CAT A fit-out bar the demonstration zones.

THE FUTURE So let us imagine that our post-COVID office is not just smaller, but now better designed and better lit for its use, and is sustainable both in its operation and in its procurement.

But what might it look like? The Swedish government is already questioning the ubiquitous recessed 600 x 600 LED panel as a source of bland and visually uncomfortable spaces. Research shows that most space users prefer direct-indirect schemes and some control over their space.

Moving the lighting design on from an overly simplified task surface allows more consideration of lighting for people.

A circular economy is based on the principles of designing out waste and pollution, and keeping products and materials in use. From an office lighting perspective, this suggests not disposing or replacing fittings before end of useful life, extending useful life by ensuring components can be replaced or upgraded (particularly the driver within the LED fitting), setting in place supporting maintenance, warranty or lighting as service structures, reusing redundant fittings elsewhere and ensuring fittings can be readily dismantled into component parts and materials.

Our objective is to combine effective working plane lighting within a visually comfortable space while achieving environmental sustainability over whole scheme life. By taking a holistic and intelligent approach to lighting design, the energy savings made in other areas of a scheme allow a ‘carbon budget’ for some ‘feature’ lighting which hugely benefits people’s emotional response to the office space.

This article first appeared in issue 27.4 of Government Business Magazine

‘The CAT A paradigm must now itself be consigned to the skip and revisited to better align with current requirements’

Bob Bohannon, MSc FSLL, MIET, is the current president of the SLL

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Wellbeing

November/December 2020

WELL CONNECTED Interior designer and health coach Kaye Preston and lighting designer Kael Gillam explain the aims of Designers Mind esigners Mind is a forum and community where designers from a variety of backgrounds and specialisms can share their knowledge and experience to raise awareness around mental health and wellbeing in the workplace. The community was founded in 2019 by Kaye Preston, also a WELL AP and health coach, with the goal of helping to raise awareness and improve the mental wellbeing of designers at work.

As well as ourselves, the core contributing team comprises interior designer Rosalind Poerwantoro and workplace design strategist Rhiannon Laurie, both also involved/qualified in the wellbeing sphere.

As designers, we have unique pressures from countless different sources in our professional lives, all seemingly centred on creating the best and being the best. Clients expect nothing but excellence from the consultants they employ, and designers are notorious for never being quite satisfied with even their most accomplished works.

We are also a pretty tireless lot; late nights, weekends and holidays are often no boundary to ensuring that projects get the attention they so rightly need.

With this sort of internal and external pressure, it is not difficult to imagine how it begins to cascade into a designer’s personal life. The all too common 24/7 working

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mentality erodes the idea of a work-life balance; if we’re unable to 'shut off' from work, then we’re never really done working.

Sleep becomes less important. Eating healthily gets thrown to the wayside for whatever is open when you trudge back from the office.

Making time to socialise starts to become too much effort to sustain.

Our aim at Designers Mind is to cut through the status quo and help designers establish habits that benefit themselves across all areas of their lives. We know that there are damaging yet long-established norms in the design industry that wear people down and cause burnout. Our mission is to shake off stereotypes and rewrite potentially damaging proscriptive routes to success.

We believe that everyone has their own way of living and working that is most beneficial to them. We are strong advocates of listening to your own body and responding positively to what you hear. Awareness is the first step to wellness; this encompasses our physical, mental, emotional, social and spiritual wellbeing. Kaye’s passion as a health and lifestyle coach is to simplify wellbeing and help people incorporate it into their day without feeling as if they’re adding to an overwhelming 'to do' list. She believes that everyone should be able to create a wellbeing toolbox, an arsenal of strategies that helps you maintain balance. When we start to put our wellbeing

‘As designers, we have unique pressures from countless different sources in our professional lives’

first, we find that we are actually happier, more productive people in all aspects of life.

We plan to host workshops and seminars with designers to find these tools and learn how to implement these techniques in their daily lives. With our own unique backgrounds, we hope to be able to contribute valuable perspectives, advice and strategies learned both from our personal lives and our professional study.

We look forward to being able to do this once it is safe to do so, as we feel that this opportunity for a very personal connection is at the heart of fostering good wellbeing.

With this sense of intimacy in mind, we have encouraged members of the design community to share their stories about personal wellbeing on our website. In doing so, we hope that others can find solace and warmth; we want designers to know that they are not alone both in their triumphs and their disappointments.

sll.org.uk

Wellbeing

November/December 2020

We find that empathy is one of the greatest gifts that can be given to someone who is in need. Once you feel that you can relate your problems to the problems of others, the burden lightens; as the saying goes 'a problem shared is a problem halved'. By encouraging designers across all walks of life to tell their stories, we hope that we can foster camaraderie across the creative industry.

In the lighting design world, we have been so pleased to see very personal insights and stories emerge in the past year through WIL (Women In Lighting). This community was launched by Light Collective, on top of their many other activism projects, as a way to bring women in lighting design together and to the forefront of their industry. WIL’s interviews and blog posts tell incredible stories of women all over the world, all roughly focused around their fascination with light. Interviewees share stories about their passion for design, their families, their projects, their periods and everything in between. Through this initiative, relationships have been formed between strangers on opposite sides of the earth as mentors, friends and allies. According to Sharon Stammers, co-founder of WIL, one of the main positive feedbacks from the WIL project

• 1 in 6 workers experience a

mental health problem at any one time1 • Employee mental health issues cost UK companies £45bn a year due to lost production, presenteeism, absenteeism and recruitment1 • There were 602,000 cases of work-related stress, depression or anxiety in 2018/2019 in Great Britain2 • It costs business an annual £1300 per employee whose mental health needs aren’t supported2 1 Deloitte 2019 Report: Mental Health and Employers – the case for refreshing investment (January 2020) 2 MHFA England website (June 2020) – Designers Mind (figures based on UK data and not specific to the design profession)

Twitter: @sll100

is how many people have felt empowered by hearing the honesty of those women interviewed. By admitting frailty, fear, doubt and being open about intimate and personal issues, the interviewees have paved the way for all of us to speak more freely about the things that affect us outside our work and how it impacts our lives.

During the summer lockdown, we were asked to give a short presentation on the topic of wellbeing as part of the SLL webinar series focused on health and design. We were honoured to be able to talk to this very broad community about how the company was founded, who we are, and how we felt our initiative could assist people in lighting and engineering. The more discussions we have with specific designers, the more we have come to realise that the forum we are trying to establish serves a universal purpose across many design disciplines.

Beyond looking to form a community, we are also strong advocates of education, not only to understand ourselves better but also to understand the wider social mores behind wellbeing. We are four designers whose work focuses on creating spaces in the built environment around the ideals of safety, welfare and health.

As a collective, we are also working to advocate for employers to do their part in establishing healthy practices for the people who inhabit these spaces. Companies have a duty to support their employees in a holistic way; as much as it may be a bother, it isn’t possible to put your personal life on the shelf while at work. In this vein, we are encouraging employers to go beyond the requisite EAPs (Employee Assistance Programmes) and government minimums and truly try to understand what support their employees want and need. Establishing good practices at the office would invariably reinforce what employees will be doing with their own personal toolboxes. By establishing a strong baseline of healthy choices and support systems, such as bike shares, gym memberships, financial counselling, extended parental leave and so on, employers create a system of trust with their employees. All members of staff should have an established road map for how to help themselves not only in the event of loss, burnout, or illness, but also in navigating effective communication in the workplace on a day-to-day basis.

Core contributing team Kaye Preston (founder), interior designer, WELL AP, wellness consultant, health coach Kael Gillam, lighting designer Rosalind Poerwantoro, interior designer, Fitwel ambassador, MHFA, interior landscaper Rhiannon Laurie, workplace design strategist, WELL AP, BREAM AP, LEED AP, Fitwel ambassador

Kaye Preston (top), interior designer, WELL AP and health coach, and Kael Gillam, senior lighting designer at Nulty+, gave a presentation on 22 July as part of the SLL webinar series focused on health and design. To see the webinar go to www.gotostage.com/channel/9 9978c30d5d3478486d85f02f912d1bc/ recording/c511645aa0e04194b82ac1a 47813565d/watch For more details go to www.designers-mind.com or email info@designers-mind.com

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Project

© LPA Lighting

November/December 2020

SPANNING THE CENTURIES Two SLL presidents, past and present, came together to create the new lighting for the historic Iron Bridge t's probably not every day that you have a former and current SLL president working together on a lighting project, in this case a historic landmark. What's more, it is located in the backyard of the Lighting Industry Association academy where both Bob Bohannon and Liz Peck teach.

The scheme was for the Iron Bridge in Shropshire, the first bridge in the world made of iron and the forebear of modern metal-framed buildings.

It is a worldwide icon for the start of the Industrial Revolution.

English Heritage undertook a £3.6m conservation project in 2017-18, which was marked with the new lighting scheme replacing 40-year-

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old flood fittings. The challenges were many: luminaires were subject to regular flood risk, nothing could be mounted on or under the bridge, cables could not be run through or across it, and daytime visual intrusion of any installation had to be minimal.

It also had to illuminate the downstream side which had previously been left dark from a key viewing point.

Goalposts were also moved midstream, as it were, when English Heritage discovered patches of the original paint colour, a redbrown, mahogany shade, and decided to repaint the whole bridge back into this colour. Mid-way through the lighting design, with budgets outlined and equipment sizes approved, the paint finish changed from a 25 per cent reflective mid-grey tone receptive to most colours, to a five per cent reflective red-brown. To maintain the required luminance with a much lower reflectance needed projectors with much higher lumen packages, and commensurately larger and more expensive, and needing larger, more visible columns.

'Instantly a relatively straightforward project became three years of careful negotiation and the overcoming of numerous challenges,' say Peck and Bohannon.

Detailed computer models of the bridge and gorge were made to determine quantities and aiming angles to ensure uniformity, while minimising glare and spill light through the filigree structure.

To gain planning permission, with the support of Historic England, the use of wooden columns was proposed to soften the daytime appearance. These had bespoke brackets to bunch the projectors tightly together to reduce height, and custom bases to ensure that the wooden shafts were well above extreme flood levels. These were then located in as unobtrusive places as possible. The floodlights are mainly narrow beam, cross aimed horizontally to capture as much light as possible on the solid stone abutments to minimise glare and spill light.

Overcoming cabling restrictions, automatic controls talk across the river by radio, while GSM links enable Telford and Wrekin Council to change programmes from any computer or smartphone.

The final effect delivers a warm white light scheme during the week and an innovative dynamic ‘furnace mode’ of red and amber overlaying a dimmed back white scheme for the weekend. The dynamic effect is created by altering the intensity of the red and amber floodlights across the bridge, suggesting the movement of the light from the fiery skies of Coalbrookdale.

The scheme was launched during the Ironbridge Festival in September.

‘Imagine the effect of the bridge lit by the fires from the furnaces and forges of Coalbrookdale,’ – Morgan Cowles , head of conservation and heritage at English Heritage, Sunday Times

sll.org.uk

LR&T essentials

November/December 2020

NATURAL SELECTION Iain Carlile focuses on three recently published Lighting Research and Technology papers which examine different aspects of sunlight and daylight ingh et al have investigated methods to increase the efficiency of mirrored light pipes using a simple to manufacture, low-cost, laser-cut panel (LCP) collector. The proposed LCP collector has no moving parts making maintenance less costly when compared to other systems such as heliostats.

A mathematical model investigated different parameters such as azimuth and altitude of the sun for varying geographical locations. The model enabled the design of an LCP collector system, tailoring its parameters to best suit the latitude of the installation. The authors note that the LCP works better with direct sunlight rather than the diffuse light of a cloudy sky or early morning sunlight, and that therefore further research is required to make the collector suitable for use in areas of low annual sunshine.

Turning to a different aspect of natural light, Mardaljevic et al focus on a novel real world application of high-dynamic range (HDR), camera-based measurement of cumulative daylight dose. The method derives illuminance values from the HDRacquired luminance at numerous patches (of known reflectance) on the surface of a wall. The patches thereby act as proxy illuminance meters allowing the illuminance field across the entire visible surface to be modelled using a Kriging algorithm.

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This approach has particular application in historic/conservation spaces where the exhibits and materials may be very sensitive to light.

The authors validated the method in both controlled and in-situ applications over extended periods which showed the technique to have comparable accuracy to illuminance data-logging devices commonly used in such applications. The equipment consisted of a consumer digital camera and tethered computer, providing continuous monitoring for periods of six-plus months, at a capital cost saving compared to multiple illuminance meters. The authors make recommendations for a solid-state HDR camera (minimising moving parts and ongoing maintenance) and micro PC setup to replace the test equipment.

Jakubiec et al present a post-occupancy study of office buildings in Singapore, correlating the results with climate-based daylight modelling (CBDM) and electric lighting simulations of the buildings. A total of 326 participants took part across 10 different daylit offices.

From the study, significant correlations were found between CBDM and the reported occupant satisfaction with access to daylight, interesting views, visual comfort and perceived lighting levels. It was found that CBDM metrics such as continuous daylight autonomy and useful daylight illuminance combined (100-3000

ď ´ LCP with separate wedges for each unit. Enlarged view shows loss in efficiency caused by interaction between adjacent wedge and exiting rays (Singh et al)

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lux) correlated more strongly with subjective results than electric lighting sufficiency metrics (300-500 lux). It was also found that simple statistical representations of annual daylight distributions (mean and median annual daylight illuminance values) provided greater correlation than CBDM. Based on their findings the authors propose new metrics for occupant satisfaction considering daylight access and quality of views.

Iain Carlile, FSLL, is a past president of the SLL and a senior associate at dpa lighting consultants

Lighting Research and Technology: OnlineFirst In advance of being published in the print version of Lighting Research and Technology (LR&T), all papers accepted for publishing are available online.

SLL members can gain access to these papers via the SLL website (www.sll.org.uk) Designing a laser-cut panel for light collection for daylighting using a generalised mathematical model S Singh, DS Bisht and H Garg Reconstruction of cumulative daylight illumination fields from high dynamic range imaging: Theory, deployment and in-situ validation J Mardaljevic, S CannonBrookes, N Blades and K Lithgow Long-term visual quality evaluations correlate with climate-based daylighting metrics in tropical offices – A field study JA Jakubiec, G Quek and T Srisamranrungruang

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Events 2020

For up-to-date information on all SLL events please visit the website: www.sll.org.uk

2-6 NOVEMBER Applying Light for Human Health: Lighting Research and Technology Symposium (online event) www.sll.org.uk 11-12 NOVEMBER LuxLive Digital Festival Online event with overall theme of health and wellbeing with four strands: Emergency Lighting, Smart Lighting, Workplace, and Lightspace Festival.

The SLL Young Lighter 2020 final will also form part of the event https://luxlive.co.uk

12 NOVEMBER Lux Awards Online event (including announcement of SLL Young Lighter 2020 winner) https://luxawards.co.uk

24-25 NOVEMBER Build2Perform (CIBSE online event) Venue: Olympia London www.build2perform.co.uk

Society of Light and Lighting

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