Light Lines May/Jun 20

CIRCULAR REASONING Rethinking recycling

IN THE DARK

What is healthy lighting?

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

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 LL4 2020 IS 11 MAY

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

FROM THE EDITOR

The coronavirus pandemic has seen the inevitable cases of human greed, selfishness, stupidity and exploitation. But outweighing them has been the human impulse to reach out and help, to respond with humour, compassion and creativity, and to shine a light in the darkness. We may be physically distanced but we are finding different ways of coming together.

A modest initiative quickly came from the SLL, the ILP, the IALD and Zumtobel Group UK who have united to create the Light Minded Movement, an Instagram project allowing the lighting community to communicate through images (see p4). There will be many more such endeavours, simple, spontaneous and positive.

What we can only hope is that we learn a lesson from this, though history is not encouraging. As writer and environmentalist George Monbiot put it in The Guardian, 'We have been living in a bubble... of false comfort and denial. Now the membrane has ruptured, and we

find ourselves naked and outraged, as the biology we appeared to have banished storms through our lives.'

Our cavalier disregard for our planet and its ecosystem is all part of the same syndrome. As John Bullock points out in his examination of the circular economy (see p5), the lighting industry has to look to its own backyard in this respect.

'The temptation, when this pandemic has passed, will be to find another bubble,' continues Monbiot. 'We cannot afford to succumb to it. From now on, we should expose our minds to the painful realities we have denied for too long.'

CURRENT SLL LIGHTING GUIDES

SLL Lighting Guide 0: Introduction to Light and Lighting (2017)

SLL Lighting Guide 1: The Industrial Environment (2012)

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 (2014)

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)

FROM THE SECRETARY

Strange times. I hope you are well, mentally and physically, and the changes due to Covid-19 are not drastically impacting your life and work.

As you can imagine, following the government advice in mid-March regarding coronavirus, CIBSE did not delay in postponing events and encouraging staff to head home with their laptops. We have very good systems in place including Office 365, Microsoft Teams and 8x8 telephones to enable home-based working. In a way it is business as usual but in a different environment and without face-to-face communication with colleagues and members. The situation has, however, encouraged us to pick up the phone more often instead of sending emails.

For me there is little change, my working week before was pretty much split 50/50 between home and Balham. All face-to-face meetings have stopped and regional events postponed until further notice. All of the SLL committees are still meeting via Teams software and I thank them all for their continued support of the society. We will host more seminars online via webinars. On 12 May Kristina Allison and Katerina Konsta will present and discuss their alternative route to CEng (see p8). Details will be emailed to you soon and we may also be bringing the SLL LightBytes to your laptop. The LG2: Lighting for Healthcare Premises webinar hosted in April can be seen on the CIBSE YouTube channel.

This year’s annual general meeting will not take place. As a division of CIBSE (which is the legal entity), there is no legal requirement for the society to host an AGM although it is a good opportunity to review the previous year and look forward to the next. CIBSE will host a virtual AGM, which is required under the royal charter and by-laws. We do, however, intend to say thank you to current president Jim Shove, who has had a great and busy year directing us,

and to welcome the new SLL president, Bob Bohannon, on 21 May. Notification of the SLL officers sitting on the council and executive for 2020-2021 has been sent to you separately, and we will email all members a link to the 2019 Annual Report on 21 May.

In the current climate of uncertainty CIBSE is committed to doing all it can to support our members and to provide access to the professional networking, knowledge and CPD provision that our members and others will need even during the present restrictions on work and gatherings. The regions, divisions and groups are a key element of that and we are keen to support their activities virtually as best we can.

With many of you working from home your benefits of membership have never been more important. You have access to all of the SLL publications online through the CIBSE Knowledge Portal. It doesn’t matter where you are in the world, just log in and they’ll be there.

We have again partnered with Clarion for this year’s Lighting Design Awards and LuxLive. Although the date of the Lighting Design Awards has changed from its usual May timing to 22 September, we are looking forward to both events and hope to see many of you there. Good luck to all who have been shortlisted.

We do look forward to the situation settling down and to a time when we are back to normal. Normal seems a wonderful place right now.

Thank you all for your support for the society.

BRENDAN KEELY BKEELY @CIBSE.ORG

‘With many of you working from home your benefits of membership have never been more important’

EDITORIAL SECRETARY’S

END OF LIGHT ISSUE

What is the circular economy and why is it Important?

John Bullock explains

CHANCE TO CHARTER

A NEW COURSE

Katerina Konsta and Kristina Allison look at taking the alternative route to gaining chartered engineer status through CIBSE

WELL MEANING

The focus in the workplace is now firmly on health and wellbeing. But do we know what lighting for health is or how to achieve it? asks Andrew Bissell

DIRECTION OF TRAVEL

Iain Carlile looks at three of the most recently published LR&T papers on the lighting of roads and train stations

EVENTS

CIBSE SWITCHES EMPHASIS TO ONLINE THE

As part of its response to the coronavirus outbreak, CIBSE is planning to provide knowledge and training through webinars and online learning, said chief executive Stephen Matthews.

One of the planned SLL webinars, in mid-May, is with Katerina Konsta and Kristina Allison who will discuss achieving chartered engineer status through CIBSE using the alternative route (see p8).

The membership team and interviewers are also aiming to conduct interviews remotely using various platforms. 'No doubt we shall find many more ways of keeping everyone safe and informed, trying to make the abnormal more normal in the days ahead,' said Matthews (above).

With face-to-face events postponed, the institution will be supporting its volunteer network to set up virtual meetings where needed, said Laura Webb, director of membership. 'We will be moving to produce as much online content as possible so we can support members’ CPD needs,' she said. 'We will also be increasing our regular membership briefing webinars to support individuals with the membership application process, as well as having pre-recorded webinars available to watch now.'

CIBSE staff are now mostly working from home, but connected to the institution's systems, including phones and Microsoft Teams. 'We are looking to support the work of our volunteer groups and networks through our recent investment in Office 365 to support virtual CIBSE activities in the coming weeks,' said Matthews.

For the full statement: www.cibse.org/news-and-policy/march-2020/a-messagefrom-stephen-matthews,-chief-executive www.cibse.org/webinars; www.cibse.org/onlinelearning

ON THE LIGHTER SIDE...

There's a touch of the Olafur Eliassons about a series of lights created by Milan-based Mandalaki Design Studio. The Halo Edition provides illumination with projections through lenses, and results from the studio's research into optics and white light frequencies. The table lamps, floor lights and ceiling fixtures project colourful sun-like orbs on to their surroundings.

The process entails altering white light to eliminate unwanted frequencies and curating the colours that are emitted. The angle

of refraction is also manipulated producing a vivid palette of colours. Four of the five versions have adjustable heads.

'We designed a light that is an art object,' say the designers. 'We want people to use Halos like an optical brush, painting an environment with shapes and hues.'

https://haloedition.com

LIGHTING BODIES LAUNCH JOINT INITIATIVE

The SLL, ILP, IALD and Zumtobel Group UK have launched a social media initiative called the Light Minded Movement. The Instagram project aims to encourage wellbeing among those working in lighting. A theme is being set each week and people are posting pictures which relate to it.

'It's an opportunity for the lighting community to communicate through images, showing how they are coping with the changes in their working conditions, life at home, family, how their days have changed and what they are doing to keep mentally well,' said SLL secretary Brendan Keely.

The administrators are Keely and Juliet Rennie from the SLL, Emma Cogswell of the IALD, Jess Gallacher of the ILP, and April Dorian and Dan Hodgson of Zumtobel Group UK.

The LMM will also refer people to the websites of Mind and the Samaritans. 'The term ‘social distancing’ is misleading and alienating,' said the launch statement. 'We need to come closer, albeit not physically.'

To use, go to www.instagram.com/ light_minded_movement/

END OF LIGHT ISSUE

What is the circular economy and why is it important? John Bullock explains

The typical way that we think about the things we use assumes that we keep something for as long it's helpful to us, after which we throw it away. How it gets thrown away rarely enters the consciousness of the user/disposer. What that has meant across the generations is that we have continued to extract materials from the planet rather than consider what happens when those materials run out.

The circular economy takes a wider view. Just because one person has finished with a product does not mean

that there is no value left in it. When we’ve ‘finished with’ a motor car, we understand that there could be a lot of residual worth left in it and, rather than scrap it, we sell it on at a lower cost. That is the beginning of the circular economy process... though nowhere near the end of it.

As products age, some components wear out and need to be replaced, and if there’s one aspect of the circular economy that has already had an influence on product design it’s the idea that goods should be repairable. As long as the product in its entirety can continue to be of service, it will have a useful life. It's what happens at the very end of active life where the true circular economy can be seen.

‘The climate crisis has brought materials exploitation into sharp relief’

The climate crisis has brought materials exploitation into sharp relief. The growth of the recycling industry as an answer to repurposing spent materials was

a great step forward – provided no one looked at the energy that was required in that repurposing. For example, aluminium is one of the most reused metals on the planet. It's reckoned that 75 per cent of the aluminium that has ever been processed is still in use. Unfortunately, there is an energy cost that comes with that. When an exhausted aluminium component goes for recycling it involves smelting the metal to create a stock billet that can be sold and reused – and that takes energy. When the aluminium billet is then smelted (again) to create another component, that takes yet more energy.

‘Should the entire luminaire be capable of disassembly and every component become available for reuse?’

But what if the original component still contained residual value? Isn’t there a way that the component can find its way back into the production stream directly?

That new attitude to used components is at the heart of the circular economy.

WHY IS IT IMPORTANT IN THE LIGHTING INDUSTRY?

Historically, we have always had a version of the circular economy within the lighting industry. The replaceable parts were the light source (let’s call it a ‘lamp’) along with any associated electronic circuitry. The luminaire body lasted for as long as it was needed – and that could be any number of iterations as the lamps were changed many times during its active life. It's why many of us have lighting fixtures in our homes that may be decades old.

The LED changed that view. It didn’t help that a lot of the new companies that entered the marketplace in the early years of the 21st century had little or no awareness of the fixture+lamp tradition. So it was that we have seen a generation of LED luminaires where the LED engine (let’s call it an engine

for convenience, though it may just be a chip array or a PCB) was cemented into the luminaire body, which then doubled as the heatsink. And, because this is only an end-of-life issue, not many people worried about what would happen further down the track when the LED started to fail.

We are now further down the track and things need to change.

But it's not a straightforward journey. There are questions about how deep a circular economy approach needs to go. Is this really just about being able to change exhausted components (LED engines and drivers) and not worry about the luminaire housing, or should we take a more principled approach which says that the entire luminaire should be capable of disassembly and that every component should become available for reuse?

The European Commission (remember them?) is currently exploring ways of supporting the reuse of components and is looking to develop a set of standards that will define the principles, concepts and terminology that we can all use to ‘normalise’ circular economy processes.

In truth, there is no shortcut to this process. Trying to convince us that a luminaire body doesn’t need to be a part of the circular economy is another way of kicking the issue down the road – again. Most material use goes into the luminaire housing (by weight/mass). It’s in the housing where the core of the problem lies, so we can’t ignore it. Athough it’s not the only issue.

A currently unresolved problem is potentially more crucial to our future – or, at least, to the future of the LED. Whereas a luminaire housing is made up chiefly of aluminium and/or steel (though the industry is seeing more use of plastics, which is not a good idea), the LED engine and the driver are full of tiny amounts of rare earths and precious metals. There is currently no commercial (aka profitable) way –and in some instances no technical way – to recover those minerals and you might say that the most valuable part of the LED luminaire still ends up in landfill. That is crazy, but it's where we are at the moment, and the situation can only become more problematic. At the moment we’re not seeing a lot of LED luminaires at their end of life –but watch this space.

HOW THE INDUSTRY MIGHT RESPOND

Happily, we’re already seeing some great responses by manufacturers. New ranges were expected to be launched at Light+Building in Frankfurt this year (now let’s see what September brings) that demonstrate how the circular economy can be applied to commercial product. Other companies have realised that they’ve been working on circular economy principles for years and have found, at last, a reason to shout about it. As I say, this is by no means a new approach to product design – it's more a case of refocusing on good design practice.

What’s not yet been resolved is how the circular economy operates in practice. It's one thing making a luminaire that can be disassembled, it's another thing to create an economic model where such dis- and reassembly can work. Most manufacturers are

taking the approach that they will be the ones who retain control of their products, possibly via an upturn in the acceptability by clients of Light as a Service (LaaS). This is a reasonable attitude to take if we think in terms of large-scale projects where thousands of products are installed in a building, but it’s not the real picture.

I have nothing to support these percentages, but let’s just assume that the total output of a lighting company might split 80:20 between lots of smallscale projects (80 per cent) and a small number of large-scale projects (20 per cent). If the manufacturer is only paying attention to the headline projects, then 80 per cent of its output risk is being ignored – and that is hardly a circular economy model.

Using motor car servicing as a model we can see another way. Small, privately owned garages are licensed to work on particular motor brands, and they effectively take the pressure off the manufacturers themselves. This is one way to envisage a future that contains the majority of a lighting manufacturer's output. But we have to create a usedluminaire model alongside – and that’s going to take some effort.

At least we have a short amount of time before this becomes a pressing

Background to the circular economy

issue. Circular economy fixtures are only just coming onstream. It’ll be a number of years before the majority of those fixtures will require some kind of refurbishment. That’s the amount of time that the industry has to get a servicing sector in place.

The modern concept of the circular economy came out of Cradle to Cradle: Remaking the Way We Make Things (2002) and The Upcycle (2013), the influential books by William McDonough and Richard Braungart. McDonough, a US architect, and Braungart, a German chemist and founding member of Germany's Green Party, insisted that the linear cradle-to-grave approach was no longer fit for purpose and proposed a system of product design that ensured that materials remained ’in play’ rather than being lost to landfill.

https://mcdonough.com/writings/cradle-cradle-remaking-way-make-things/

https://mcdonough.com/writings/the-upcycle

The Cradle-to-Cradle philosophy influenced Ellen MacArthur, who saw the impact on the world’s oceans as a long-distance yachtswoman. She launched the Ellen MacArthur Foundation in 2010, dedicated to developing a circular economy.

MacArthur was invited to speak at the World Economic Forum in Davos in 2012. That led to the WEF’s Platform for Accelerating the Circular Economy (PACE), launched in 2017 to develop financial models for circular economy projects.

www.ellenmacarthurfoundation.org/

www.weforum.org/projects/circular-economy

John Bullock, MSLL, is principal of John Bullock Lighting Design, publisher/editor of The Light Review and a regular commentator/speaker on the circular economy.

The SLL is currently developing a Lighting Factfile on the circular economy.

CHANCE TO CHARTER A NEW COURSE

Katerina Konsta and Kristina Allison both recently took the alternative route to chartered engineer status through CIBSE. Katerina outlines why it is an important step, while Kristina gives a personal view of the process

THE BENEFITS: KATERINA KONSTA

If you are working in the lighting profession, perhaps a key question is why would you want to become a chartered engineer. In our view, professional registration brings value to various parties: the individual, the employer and society generally.

On a personal level, becoming a chartered engineer is a means of improving career prospects and employability. It provides the individual with an enhanced status, arguably leading to higher self-esteem and career progression. Pursuing chartership also proves a commitment to continuous professional development (CPD) and equally demonstrates a professional attitude that is valued by both employer and clients. In addition, CEng status is evidence of expertise and recognition of competence independently assessed by your peers. You have the opportunity to join a community of chartered engineers, connect with other members worldwide and build new relationships with other specialists in your field. Incidentally, being a chartered engineer is also one of the accepted occupations for countersignatories.

Organisations that employ professionally registered staff benefit from a globally accepted assurance that the employees have satisfied a rigorous assessment of

 From Katerina's CEng project: typical animation frame showing the simulation output of potential veiling luminance (disability glare) for helicopter pilots

Katerina Konsta, CEng MCIBSE MSLL, is a senior lighting designer at Arup and SLL representative for the North West region

‘Professional registration brings value to various parties: the individual, the employer and society’

their engineering competence and the credentials claimed have been verified. CEng is an internationally recognised title which enables greater flexibility in staff mobility and it may have a positive impact on recruitment and retention of staff. It also has an increased technical and managerial credibility especially when it comes to senior roles and career development. Chartered engineers have a personal obligation to abide by a code of conduct which, in turn, can enhance company reputation through ethical behaviour. Society as a whole, on the other hand, can have more confidence in the work of professionally registered members nationally and globally. Professional registration gives the assurance of an ethical and sustainable behaviour by its members.

CHALLENGES

Coming from a design background with academic qualifications in architecture and lighting design, the first and most obvious question that comes into your mind is whether you are eligible to apply and if lighting and engineering cross paths. But what is engineering? In simple terms engineering is the use of science and maths to design things or solve a problem.

As lighting specialists, of course, this is what we do on a daily basis.

Finding a mentor with the relevant experience in lighting who will provide you with the support and guidance that you need along this journey can be challenging. We are a small industry and the number of mentors that have been through either the standard or the alternative route is very limited. This is where as a society we would like to reach out and help other members who are interested in applying.

Lastly, choosing a subject for the engineering report can be overwhelming. It is important to propose a topic that you know well and to ensure it clearly answers how you intend to demonstrate your technical knowledge and understanding. The intention of the technical report is to identify the engineering principles involved in the subject rather than, for example, describing a project that you have been working on.

PERSONAL EXPERIENCE: KRISTINA ALLISON

I work for a large multi-disciplinary company where chartered status is highly valued. However, when I investigated applying for the process, I discovered it wasn’t quite as straightforward as it had been for my electrical or mechanical colleagues. For a lighting designer, usually the alternative route is the route to chartership. This meant that I would have to write a technical report that demonstrated that I understood the ‘fundamental mathematics and science’ behind my subject.

From the time I decided to apply and actually received my Engineering Council certificate took around two years. There are two main steps to the process: the first step is to join as a member grade with a certifying body, so in my case CIBSE. The second step is to apply to follow a route to chartership, which is determined by previous qualifications.

Kristina Allison, CEng MCIBSE MSLL, is a specialist lighting designer with Atkins Global. She is co-chair of the SLL education and membership committee

What is professional registration?

Professional registration is recognition through membership of a relevant professional engineering institution that an individual’s competence and commitment has been assessed and that they have attained the standard required for admission to the national register at the appropriate level (for example, chartered engineer).

For me it was the alternative route. I decided to write my report based on a live project that I was working on at the time. In hindsight perhaps this made more work for myself but benefited both me and the project because of the additional research I was bringing to it.

It did require a lot of effort and time dedication, so I won’t say the whole thing wasn’t hard. But like any endeavour, once complete the feeling of satisfaction and achievement makes all the effort worthwhile.

Engineering is about problem solving and so is lighting design, and this whole process highlights the similarities between both professions. I’d suggest to anyone interested in becoming chartered to go to the CIBSE website and look at the criteria required and take it from there. It may highlight where further experience is needed and will give you a clear guide as to what CPD topics you might need to explore next and where to find them. Using the CIBSE website to record your learning in My CIBSE helps and is a requirement for chartered engineers.

PREPARING FOR THE INTERVIEW

Once my report had been accepted the next step was to prepare a presentation for the interview. I found by this time that I had become so absorbed by my subject that this final part was fairly straightforward. To help me get ready for the interview I ran through the presentation with two colleagues who only partially knew about my work. The opportunity to go through it and have questions asked about the work I had been doing was very valuable, as an outside perspective can highlight oversights that you can then make sure you cover during the final interview. I would recommend that you make sure you are completely prepared for your interview and have two printed copies to take with you, plus a digital copy on email and USB stick just in case.

RESULTS

My employer recognises the competencies required to achieve chartered status (though perhaps not the extra mile the alternative route can require) and since completing the process I have been promoted,

which obviously adds even more satisfaction to the whole endeavour.

As we know, being a more recent discipline it can be hard for lighting designers to gain the same level of respect as other professions, so this demonstrates that lighting design is an equally valid career. Our clients also recognise chartered status, and this therefore benefits the company during project bids too.

IS IT WORTH APPLYING?

Having now completed my chartership journey, I would recommend applying and taking on the challenge. I feel I have learnt so much along the way and it has encouraged me to explore new things and keep on top of my CPD, including diverse topics.

Finding a suitable mentor with relevant support along the way might be a challenge but it is all mostly process based, so anyone who has been through it and passed can help. Being part of the SLL means that there are chartered lighting designers out there who I am sure will help if approached. Since passing my interview I have been asked by several of my colleagues for support and I'm happy to help more people obtain this professional status.

‘I have learnt so much along the way and it has encouraged me to explore new things’

Alternative route to MCIBSE CEng: the process

This route requires candidates to demonstrate their competence through the submission of an engineering practice report (and supplementary documentation), followed by an interview assessment. There are two UK application closing dates a year: February and August. Applications will be accepted throughout the year, but interviews will only be held during two designated interview periods each year: April/May and October/ November.

• If you do not hold any qualifications or you do not meet the academic standards you can still obtain CEng once your MCIBSE application has been approved

• Application + engineering practice report

• Competence review interview

• Assessment + approval by CIBSE members panel

• MCIBSE

• Further learning to master level OR technical report route application

• Professional review interview OR technical report + professional review interview

• Assessment + approval by CIBSE registration panel

• CEng

For full details go to:

www.cibse.org/membership/ find-your-grade/member-grade

 Although now more than a decade old, Cundall's scheme for the RIBA Award-winning repurposing of Bourneville Place, Birmingham, is an exemplar of use of daylight

WELL MEANING

The focus in the workplace is now firmly on health and wellbeing. But do we know what lighting for health is or how to achieve it? asks Andrew Bissell

The past few years have seen a huge shift in workplace design and the focus is now firmly on health and wellbeing in all its facets, including lighting design. This change has come about from the introduction of standards and guides such as WELL, Fitwel and the BCO Wellness Matters publication, to name a few. Alongside these more recent documents, which are championing health and wellbeing, are the stalwarts of the lighting industry such as the SLL Lighting Handbook, SLL LG7 (Lighting for Offices) and the likes of BSEN12464-1 (Indoor Workplace lighting). These documents focus on our visual needs when lighting spaces.

In addition to the above you also now have almost weekly case studies, research papers and opinion pieces (such as this) on lighting design and its impact on health, wellbeing, productivity, alertness, sleep quality and so on. Then there's the BRE's research project, The Biophilic Office. The question is, between all these documents and armed with all this knowledge, whether we still actually know what healthy lighting design is.

The phrase 'healthy lighting' relates to learned papers such as Measuring and Using Light in the Melanopsin Age (by Prof Robert Lucas et al) and Light as a Circadian Stimulus for Architectural Lighting (by Mark Rea and Mariana Figueiro of New York's Lighting Research Center), among many more. Equally the phrase healthy lighting captures all the different badges which the standards, guides and manufacturers now use, such as circadian lighting, human centric lighting, biodynamic lighting and equivalent melanopic lux.

I keep writing the phrase ‘to keep things simple, healthy lighting means…’ but no sooner have I written the phrase than I delete it as the reality is that designing healthy lighting is not simple. Why?

There are a number of reasons. The first and most significant reason is that in the world of lighting (this includes scientists, researchers, designers and professional bodies) there is currently no agreement on what the criteria should be. Furthermore, there are no criteria on what we absolutely shouldn’t do, which is far more of an issue. We will come back to this. Other reasons are more commercial. For example, developers need to see a return on their investment and the sooner the better – does installing a healthy lighting system achieve that?

© Martine Hamilton Knight

the

Outstanding and WELL

Gold certification, was designed as an exemplar green building and to enhance the wellbeing of occupants. Lighting design was by GIA Equation (clientfacing floors and staff social/informal working areas) and Hoare Lea (openplan offices and back-of-house areas)

Also, products labelled as ‘HCL compliant’ or ‘Circadian Certified’ or ‘Suitable for WELL’ are more expensive. How do you measure the return on a light fitting with regards to a person’s health and wellbeing?

Where the current healthy lighting criteria are concerned, the WELL standard requires 200 EML (equivalent melanopic lux) vertically at the eye for four hours a day (be careful how you design the lighting for a sit/stand desk). WELL says this could be with daylight but does not insist on it. Rea and others have developed a metric where a result of 0.3 to 0.7 means that you are receiving enough quantity and spectral composition of light at your eye so that your circadian system is

being stimulated. Below 0.3 your circadian system is not being stimulated and above 0.7 your circadian system is being saturated and more light will have no additional benefit.

The BCO Wellness Matters document, published in June 2018, talks about views, the quality of the view, equitable access to views, material colours and brightness. But it offers no defined criteria that could allow you to say that you have absolutely satisfied the document, or indeed that you are about to lease or work in a space which does not satisfy the document.

The SLL Lighting Handbook, released in late 2018, provides a comprehensive explanation of circadian lighting in Appendix 2. In conclusion, however, it also does not offer a set of criteria to follow or meet. So is that it? Should we do nothing and carry on with the blanket levels of uniform light which are commonplace in many offices? No.

What we do know is that daylight has a positive effect on our health and wellbeing. We know that the shift in colour from sunrise, through midday, sunset and to darkness impacts our non-visual system to reset our body clock and adjust our alertness

and sleep. Therefore, healthy lighting design must be about utilising daylight. But what do we do if we cannot do that?

The only reason that every occupant in a building does not have access to good quality daylight, in other words healthy lighting, is money. It certainly isn’t through a lack of understanding of how to design such spaces as this has been done many times in the past. Quite simply the cost of land in cities, especially London, and the cost of building are such that developers must maximise the footprint and building height. Unfortunately, this leads to deep-plan office floors and buildings with little or no quality of view as all the occupants see is the deep-plan office across the street. Occupants sometimes can’t even catch a glimpse of the sky.

Equally, the height of buildings keeps increasing and Manchester in particular is seeing this currently. In our own office, on the 10th floor, we have recently lost our view of the Derbyshire hills courtesy of a new building two blocks away. Essentially those on the upper floors are ok, but those down at street level, and especially if they are set back from the window, are not going to receive their

p Deloitte’s new UK and north-west Europe HQ in London,

largest office in the world to achieve both BREEAM

© Overbury

circadian stimulus from natural light. Does this introduce a long-term problem for developers? As office workers become more educated about the positive impact of daylight and therefore the detrimental impact of no daylight, will they accept a job with an employer who has signed a lease on a deepplan office? Will deep-plan offices ultimately have to be knocked down as they are unlettable? Can anything be done to change the buildings to improve access to daylight?

One answer could be to push the adoption of agile working and task-based design. Research has shown that we are more tolerant of sunlight and daylight when undertaking certain tasks compared to others. For example, when we are on the phone we are ok sitting in direct sunlight, whereas if we were at our fixedscreen computer we would pull the blind down. If we think about how we may lay out the interior of an office to make use

Last year, an eight-week post-occupancy study at the offices of facilities management company Mitie in London’s Shard building attempted to assess the impact of biophilic design and lighting on workers’ wellness and productivity. The study was led by Dr Marcella Ucci, associate professor at UCL's Bartlett School, and the experimental environment was created by DaeWha Kang Design. It comprised the Living Lab (below left), an immersive working environment, and two ‘regeneration pods' (left) used for short breaks and meditation.

It involved 'circadian lighting', together with a strong component of natural light. The lighting in the Living Lab was linked to an astronomical clock: cool blue in the morning, brilliant white in the afternoon, and fire-like orange towards the end of the day. The light also subtly shifted in intensity, giving additional dynamism. The enclosed space opened out to broad views of sky and city.

The materials used for screens, floors, desks and integrated task lighting included varying shades and textures of bamboo. Luminaires were embedded in the bamboo screens and wall cladding, both diffusing the artificial light and catching natural light. The pods were a form of break-out space, enveloping users for 15 minutes at a time in a sound and lightscape designed for reflection and mindfulness.

Occupants found the experimental area more conducive than a more conventional space used as a control, says Dr Ucci. 'The study found that, in comparison with the control space, participants in the Living Lab experienced an improvement in selfreported feelings of enthusiasm – using words such as "excited" and "inspired" – and comfort – "at ease", "relaxed" – and a reduction in feelings of anxiety. While it was not possible to disentangle the specific impacts on wellbeing of individual environmental factors such as lighting, the study did find that the satisfaction with the visual comfort was much greater in the Living Lab compared with the control.' 'The overall level of satisfaction with environmental quality was quite dramatically higher in the Living Lab,' confirms DaeWha Kang. 'The lighting would be a factor in this but we looked at it through the interplay of the lighting with the textures and natural materials of the space, rather than isolating light fittings as a single factor.'

ww w.daewhakang.com/project/ the-shard-living-lab/

of this knowledge, then we could position comfy high back chairs adjacent to and facing towards the external windows. The company could then have a policy that to make and take a call you move to be in one of the window chairs.

But what if your dayto-day task means you make very few calls?

'There is no agreement on what the criteria should be. Furthermore, there are no criteria on what we shouldn’t do, which is far more of an issue'

Well those people could have desk positions nearer the windows or desk positions with the highest quality of views. Equally, those staff who are out of the office a lot are given the desk positions in the middle of the space, which is something we have recently done in our own office.

With some existing deep-plan offices there may be a need to be more brutal and cut out the slab in various places to create double-height zones to help the light enter the office. Obviously there is a loss of floor space with that approach but this could be offset through the use of smaller desks. Would we all accept a smaller desk if it meant access to more daylight? What if we all gave up 150mm off the width of our desk but in return we received 20 per cent more daylight? A similar option would be to move the facade inbound a few metres and provide an external space on each floor.

Again the working arrangement could be for the staff to use the space for certain functions (weather permitting).

Another answer, and one which I don’t subscribe to, might be that healthy lighting is provided through electric light alone. With the use of say 2700K (warm) to 6000K (cool) lamps, some fairly basic control and an astronomic time clock, the electric lighting would replicate the shift of colour and could even replicate a shift in light intensity, albeit at a much-reduced level. Say 150-200 lux in the morning, 7501000 lux at midday and back to 150-200 lux in the evening. This approach should be a concern, as if the research shows it satisfies our non-visual needs then it could lead to even deeper-plan offices and some offices with no access to daylight at all.

So, what should we do?

While we are waiting for more research to be completed in this area we need to be cautious. What we do know is that we are providing ourselves with the best lit environment if we make use of daylight and all of its qualities. As such this must be the primary light source if we are serious about designing healthy lighting. Daylight has a quality about it which we all instinctively recognise and enjoy. When offered a choice of seating we will head towards a window seat or view. Daylight also provides us with space which is animated. Patterns of light are created and move within a space throughout the day, the intensity of light fluctuates and we enjoy the change as it is natural and connects us to the outdoors.

We need to provide everyone with a view, and statements such as those in the BCO wellness guide which say, ‘views should be provided where possible’ need to change to say ‘views should always be provided’. Providing electric light which follows the colour temperature of daylight and, in a reduced way, the intensity shift throughout the day can be part of a healthy lighting solution, but should not be the sole solution. Equally, providing a space which is more natural, in that the different areas are lit in different ways, will enhance the feeling that we are connected to the natural environment. Lighting the soffit and not just faking it with recessed LED panels again gives us the sense we are outdoors as the sky is bright and not just the pavement. Is any of this new to us? Not really, but

maybe we are now realising that we should have done more.

The final question is who can make the changes needed? I get the feeling from the number of people I speak to that the desire is there to improve our workspaces but the cost of land and construction is currently an issue. Then again, we are seeing that clients will pay more for spaces that have been designed with health and wellbeing in mind. But how much of an uplift is daylight worth? Will it take more than just new research and revised guides? Do we need a statutory document which sets out minimum daylight exposure for indoor workers?

As we went to press, because of the coronavirus situation it was uncertain whether or not the LR&T Symposium on Applying Light for Human Health would still go ahead at UCL on 18 June. Please go to www.sll.org.uk for the latest update on this and other events.

This article first appeared in FX April 2019

www.wellcertified.com

www.bco.org.uk/ HealthWellbeing/ WellnessMatters.aspx

www.bregroup.com/services/ research/the-biophilic-office/

www.cibse.org/society-oflight-and-lighting-sll/lightingpublications

Andrew Bissell, FSLL MCIBSE, is global director of lighting design at Cundall Light4

DIRECTION OF TRAVEL

Iain Carlile looks at three of the most recently published Lighting Research and Technology papers on the lighting of roads and train stations

Investigating road lighting, Yang and Wei's pilot study examines whether an improvement in visual performance can be achieved by enhancing the chroma of target objects, using light sources with a larger gamut area. The experiment involved a calibrated computer display to provide a 1.5 cd/sqm uniform background with a fixation point at the centre of the display, while an off-axis target was displayed in a random direction at 13.5 degrees from that point. Twelve observers aged between 22 and 28 years with normal colour vision took part. The luminance, hue and chroma of the target was varied, and luminance values chosen to provide a negative (0.5 cd/sqm), neutral (1.5 cd/sqm) and positive (5.0 cd/sqm) contrast. Four hues were used, red, green, blue and yellow. The quantity of chroma levels varied subject to the hue and luminance due to the gamut of the display.

It was found that for both negative and positive luminance contrast the observers' detection rate was 100 per cent and reaction time was short. However, when the luminance contrast was zero, lower detection rates and longer reaction times were experienced, except for when the target had a higher chroma value. In these instances the detection rates and reaction times were similar to those with a negative or positive luminance contrast. The authors therefore note that enhancing colour contrast can be as effective as enhancing luminance contrast in improving visual efficiency.

Fotios and Robbins present a research note on illuminance on P-Class, or subsidiary, roads. The authors begin by presenting the evolution of British Standards in their approach to the specification of road lighting, dating as far back as 1927. The latest standard, BS 5489-1:2013 gives requirements for average and minimum illuminance for six classes of P-class roads.

The authors note that road lighting documents tend to state 'average illuminance' but do not clarify which type of average –

while it normally refers to mean, it could also refer to median or mode. They note that mean has the disadvantage of the value being susceptible to outlying values (unusually small or large in comparison to the rest of the data set). They also note that median is less affected by outliers.

From an analysis of illuminance at 30 subsidiary road locations it was found that median would be a more appropriate measure as the illuminances in the array of measurements did not have a normal distribution. Typically the median illuminance was 16 per cent lower than the mean. While mean and median are strongly correlated, the authors found the median was a more appropriate measure of central tendency. They further recommend that design recommendations should state if the mean or median is required and not just the average.

Hughes et al investigate methods of using lighting to influence passengers’ movement and behaviour in UK train stations. This poses many challenges, with rail stations varying in size, operating hours, fluctuating peak/off-peak times, and varying types of spaces (indoor, outdoor, modern, heritage). These can all influence passenger movement and cause overcrowding on platforms, bunching at intersections, and blockages on stairways and bridges.

From a review of 36 research papers and three review papers on the subject of behaviour and lighting, the authors identified a number of ways of using light to subtly guide and influence passengers to move through the station and use platforms more efficiently. These included varying intensity, colour (both CCT and hue), flicker/flash rate, position/direction and source/operation.

Working with stakeholders and lighting technologists, the findings of the literature review were used to identify applications of light to influence train passengers, including:

• Zones of light to identify effective boarding positions

• Zones of light to encourage passenger dispersion along the platform

• Zones of light to indicate optimum routes

• Pulsing/chasing lights to determine bi-directionality in crowd movements

• Pulsing/chasing lights to indicate appropriate walking pace

• Changes in properties to affect subjective mood/feelings of wellbeing and safety

The authors suggest these six applications be used to inform future research.

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

Road lighting: A pilot study investigating improvement of visual performance using light sources with a larger gamut area

B Yang and M Wei Research Note: Describing average illuminance for P-class roads

S Fotios and C Robbins

Identifying new concepts for innovative lighting-based interventions to influence movement and behaviours in train stations

N Hughes, B Ryan, M Hallewell, N Coad, A Grant, N Parrott, S Roberts and K Thompson

Events 2020

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

16 MAY

International Day of Light

Unesco global initiative

Events switching to later dates or adopting online formats www.lightday.org

22 SEPTEMBER

Lighting Design Awards

Venue: Troxy, Commercial Road, London E1

https://awards.lighting.co.uk

27 SEPTEMBER – 2 OCTOBER

Light and Building

Venue: Messe Frankfurt

https://light-building.messefrankfurt.com

11-12 NOVEMBER

LuxLive

Venue: ExCeL, London

https://luxlive.co.uk

12 NOVEMBER

Lux Awards 2020

Venue: TBC

https://luxawards.co.uk

LightBytes

The LightBytes Series is kindly sponsored by Soraa, Thorlux Lighting, Xicato and Zumtobel. For venues and booking details: www.sll.org.uk