Light Lines March/ April 22

The Society of Light and Lighting

LIGHT LINES

VOLUME 15 ISSUE 2 MARCH/APRIL 2022

LEADING LIGHT The new SLL Code: what has changed

BUILDING FOR THE FUTURE Approved Document L: the latest update

Editorial

March/April 2022

FROM THE EDITOR SECRETARY Brendan Keely FSLL bkeely@cibse.org SLL COMMUNICATIONS MANAGER Juliet Rennie Tel: 020 8772 3685 jrennie@cibse.org EDITOR Jill Entwistle jillentwistle@yahoo.com COMMUNICATIONS COMMITTEE: Eliot Horsman MSLL (chair) James Buck Iain Carlile FSLL Jill Entwistle Chris Fordham MSLL Rebecca Hodge Stewart Langdown FSLL Luke Locke-Wheaton Rory Marples MSLL Linda Salamoun MSLL 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 LL3 2022 IS 7 MARCH PUBLISHED BY The Society of Light and Lighting 222 Balham High Road London SW12 9BS www.sll.org.uk ISSN 2632-2838 © 2022 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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Unit C, Northfield Point, Cunliffe Drive, Kettering, Northants NN16 9QJ Tel: 01536 527297 E: gary@matrixprint.com

As this issue reflects, it's all happening on the lighting guidance and regulation front. Approved Document L has been rationalised and updated (see Towards Net Zero, p9), the SLL has recently released a succession of new and updated lighting guides, emergency lighting being the latest (Exit Strategy, p12), and the big one, the new version of the SLL Code for Lighting, is due this year (Guiding Light, p5).

It is a decade since the Code's last revision, and as editor-in-chief Sophie Parry observes, 'not much stays the same in lighting for very long and the past 10 years have been no exception'.

It is worth reflecting how much has changed and how complex the process of prescription has become. White light LEDs were around but had yet to rule supreme. We knew about the nonvisual receptor but had barely begun to grapple with quantifying the effect of artficial lighting on circadian rhthyms. The penny on the seriousness of climate change had yet to fully drop.

There is a perennial discussion on rule-making in lighting. Clearly, quantification, energy efficiency measures, for example, should never come at the expense of lighting quality. But lighting, visual and non-visual, has become more complex even for the experienced lighting designer and guidance has an important role to play.

'Like most subjects at a professional level, you think you know all about the subject until you really need to go deeper to find the answers,' says Parry. 'At this point you begin to realise just how much more you have to learn.'

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 (2021) 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 (2022) 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) SLL Lighting Guide 20: Lighting and Facilities Management (2020) SLL Lighting Guide 21: Protecting the Night-time Environment (2021) Guide to Limiting Obtrusive Light (2012) Code for Lighting (2012) Commissioning Code L (2018) SLL Lighting Handbook (2018) CIBSE TM66: Creating a Circular Economy in the Lighting Industry (2021)

sll.org.uk

Secretary’s column/Contents

March/April 2022

Contents

We are busy planning a brand-new online conference, Responsible Outdoor Lighting at Night (ROLAN), which will take place on 12-13 May. The conference will focus on the responsible application of light in the night-time environment to protect flora and fauna. Speakers will include internationally renowned specialists in the field of lighting at night.

The SLL has partnered with Dr Karolina Zielinska-Dabkowska (Illume, Gdansk University of Technology) to deliver the conference. The society will also be producing the event in association with a group of other relevant bodies, known as Founding Partners. More information regarding speakers, topics and programme, along with booking details, will be shared with you all soon as they become available.

The new LG12: Emergency Lighting guide is now available for you to download or purchase (see p12).

We take this opportunity to thank David Mooney for drafting the guide, and Sophie Parry, chair of the SLL technical and publications committee, for helping with project management. As well as the overview in this issue, David will be presenting a webinar on the updated guide which will be free to access for SLL members who have paid their 2022 subscriptions.

The SLL is now offering the Professionally Qualified Person (PQP) card, providing construction site access. This scheme is run in association with the Electrotechnical Certification Scheme (ECS). Providing you are an active member who has renewed your SLL membership subscription for 2022, you will be eligible to apply for the PQP card. The process is the same as applying for the CSCS PQP card, and you will be required to pass the ECS Electrotechnical Health and Safety Assessment.

The assessment questions and revision materials are available for download, details of which can be found on the ECS card website (see box above right). To qualify, you will need to undertake the ECS H&S assessment, rather than transferring results from the CSCS assessment. You can take the assessment remotely or at one of the ECS assessment centres. Please get in touch with me if you have any questions. The ECS will contact the society and ask for confirmation that your membership is valid when you book the assessment so please ensure your subscriptions are up to date.

On the sponsorship front, the society welcomes Recolight to the SLL Sustaining Member programme. Sustaining membership is open to companies, organisations or bodies (in the UK or overseas) which have an interest in lighting and wish to support the work of the SLL. The society Twitter: @sll100

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ECS PQP card application, including preparation and revision: ecscard.org.uk For details of SLL Sustaining Member programme: www.cibse.org/society-of-lightand-lighting-sll/sponsorship SLL Awards, Presidential Address and AGM www.sll.org.uk

works closely with Sustaining Members in technical matters, education, research and standards. For more information on the programme take a look at the website and the list of benefits for SLL supporters (see box). A list of SLL partners can be found on the back page of the magazine.

We look forward to the SLL Awards, Presidential Address and AGM on 26 May. Notification has been emailed to all members identifying the SLL executive’s nominees for 2022-2023 and it is intended to host the event in person in Manchester and online. Full details will be emailed soon.

We would like to thank Linda Salamoun for her time as chair of the SLL marketing and communications committee. Linda has stepped down from the role but we are happy to confirm she will remain on the committee. Congratulations to the new chair, Eliot Horsman, we look forward to working with him.

Finally, after more than seven years we say goodbye and thank you to Juliet Rennie who was initially recruited for the role of SLL coordinator but developed the role over time to SLL communications manager. Juliet has transferred to CIBSE marketing and we wish her the best in her new role. She has been an amazing contributor to the work of the SLL, to the volunteers and committees, authors, speakers, the members and CIBSE colleagues. For me, an amazing friend and colleague, Jules you will be missed but good to know you will still be working upstairs.

BRENDAN KEELY BKEELY @CIBSE.ORG

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EDITORIAL

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SECRETARY'S COLUMN

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NEWS

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GUIDING LIGHT Updated after a decade, the new SLL Code for Lighting is due to be published this year. Editor-in-chief Sophie Parry outlines what updates to expect

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TOWARDS NET ZERO The UK government has released the latest edition of Approved Document L. Richard Caple reviews the changes to the lighting requirements for both dwellings and non-dwellings

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EXIT STRATEGY The SLL's latest guide to emergency lighting (LG12) is now available.

David Mooney explains why the updates reflect a fundamental shift in emphasis

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OBITUARIES A tribute to two SLL past presidents, Robert Bean and Ken Ackerman

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FINE TUNING Iain Carlile finds colour a common theme among a spectrum of subjects in the latest LR&T papers

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EVENTS

COVER: Lighting scheme for the Acropolis of Athens and Monuments

by Eleftheria Deko and Associates, winner of the LIT Awards 2021 Lighting Design of the Year

Gavriil Papadiotis

FROM THE SECRETARY

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News

March/April 2022

THE LATEST NEWS AND STORIES

SLL LAUNCHES NEW DARK SKIES CONFERENCE

YOUNG LIGHTER WINS WITH PRESENTATION ON PATIENT CARE Maria Englezou (pictured below) has won the 2021 SLL Young Lighter title with a paper examining the design of healthcare facilities rooms. Her presentation explored the optimum configuration for a patient's room in terms of visual comfort, and health and wellbeing, while minimising the need for compromise.

A PhD candidate in the Department of Architecture at the University of Cyprus, Englezou's research interests focus on environmental design for buildings, visual comfort, non-visual effects of lighting, and architectural design for human health and wellbeing. Her current research focuses on studying the double room, the most widely used patient room in healthcare facilities. With a diploma in architectural engineering from the University of Thessaly and an MSc in sustainable architecture studies from Sheffield University, she has been awarded numerous academic performance scholarships.

The finals of the 27th SLL Young Lighter took place in December, the second year they have been held online, and were hosted by SLL president-elect Andrew Bissell, FSLL. The three other finalists were María Teresa Aguilar Carrasco (optimising lighting in 24-hour work centres), Remedios María López Lovillo (a user-oriented adaptive lighting control system) and Verity Rose (the impact and future of drone lighting).

This year's event included a guest speaker, SLL Young Lighter 2018, Emma Beadle, MSLL. She reflected on her winning entry three years before, which looked at children's views of the city and co-designing lighting masterplans through play and exploration. She called on the lighting community to engage with the next generation of lighting professionals through creative co-design.

For more information about the SLL Young Lighter competition and how to enter in 2022, contact sll@cbse.org

LEDs are putting a new complexion on enlightenment with the LightVision meditation headset. Designed by Benjamin Hubert of Layer for US startup Resonate, the headset features an LED light matrix and uses neural entrainment to enable 'powerful meditation to be attained simply and effortlessly, regardless of level of experience'.

The light matrix translates videos of the natural world into an ever-changing sequence of biomorphic patterns that are visible through closed eyes and proven, according to the company, to activate the brain’s frequency-following response.

Resonate has also produced other

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meditation devices including a vibrating chair and matching ottoman. Apparently research has shown that a combination of vibration, sound and light can subdue racing thought patterns and make it easier to switch off and slow down. https://weresonate.com

The SLL is organising a new online conference which will focus on exterior lighting and dark sky issues.

Responsible Outdoor Lighting at Night (ROLAN), will take place on 12-13 May. The conference will look at the responsible application of light in the night-time environment to protect flora and fauna. Speakers will include internationally renowned specialists in the field of lighting at night.

The SLL has partnered with Dr Karolina Zielinska-Dabkowska (pictured) of the Illume research group at the Gdansk University of Technology to deliver the conference. The society also aims to work with a wide range of relevant organisations, which will be known as Founding Partners.

GLOW VIRAL

A mask that glows in the dark when exposed to the virus that causes Covid-19 has been developed by researchers at Kyoto Prefectural University, Japan. Using antibodies extracted from ostrich eggs and fluorescent dye, the face shield’s detection system gives wearers an easy method of seeing if they have contracted the virus.

Led by Yasuhiro Tsukamoto, the scientists sprayed the mask with a chemical that glows under UV light if the virus is present. They aim to further develop the masks so that they will glow automatically if the virus is detected.

They hope to make them publicly available later this year. www.reuters.com/designboom.com

sll.org.uk

Rasmus Hjortshøj/COAST

Guidance

March/April 2022

Arup's scheme for Cityringen Metro Line, Copenhagen, uses asymmetrically shaped skylights to introduce natural light into underground stations: the Code's revised section emphasises that 'daylighting is an important part of the lighting in the built environment'

GUIDING LIGHT The SLL Code for Lighting is regarded by the profession as the 'lighting bible'. The latest edition, updated after a decade, is due to be published this year. Editor-in-chief Sophie Parry outlines what changes to expect Twitter: @sll100

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he Code, as it is familiarly known, is a comprehensive source of technical reference information for the lighting student, designer and engineer. I make no apology for ‘going technical’ in the opening sentence, but to understand the first principles of light and lighting requires some technical knowledge.

Curiosity is another useful attribute.

If ever you want to know why you need to know about the first principles of lighting, then the Code will become essential

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reading. Like most subjects at a professional level, you think you know all about the subject until a situation arises where you really need to go deeper to find the answers. At this point you begin to realise just how much more you have to learn.

So, if you are content to design and specify lighting by using a popular software package and accept ‘computer says yes’ or ‘computer says no’ outcomes, then maybe it’s time to understand what else you can do as a student or a professional lighter to understand why the ‘computer says no’ – and maybe even challenge your computer and prove it wrong.

The SLL Code should not be confused with the SLL Handbook. The Handbook is more about design and project considerations and applications rather than first principles, although inevitably there is some dovetailing between

'If ever you want to know why you need to know about the first principles of lighting, then the Code will become essential reading'

the two. Both publications complement each other in taking the reader on a journey from lighting theory and first principles through to the understanding and delivery of lighting applications and solutions.

The Code was last updated in 201112, around the time LED lighting was just making its debut but was still not the dominant light source. Since that time there have also been updates to the standards for daylighting, interior, exterior and road lighting, the minimum requirements for

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lighting energy consumption, both via the UK Building Regulations and the growth of whole-building energy certification schemes such as BREEAM. From a scientific aspect, there has been some progress regarding the codification and metrics for the non-visual effects of light and the impact on the circadian system. However, at the time of writing, there is still more research and codification required so it is prudent to stay informed about developments in this field.

In conclusion, not much stays the same in lighting for very long and the past 10 years have been no exception. The next 10 years will likely see a drive towards codification and adoption of some new, key lighting metrics, as well as advances in the quality of delivered electric light.

THE UPDATES The first two chapters are overviews that establish the thought processes and philosophies relative to the deeper content of the SLL Code.

CHAPTER 1 THE BALANCE OF LIGHTING This chapter outlines the deliverables, impacts and costs (financial and environmental) associated with lighting and is written by way of introduction to the essence of the SLL Code content.

CHAPTER 2 LIGHT AND HUMAN PERFORMANCE This chapter outlines the benefits of lighting in terms of task lighting, human behaviours and how they can be affected or modified by lighting and the non-visual effects of lighting on people.

Chapters 3-8 are based on the current versions of BS EN lighting standards and with additional comment where appropriate. The aim is to further assist the reader to make informed decisions on interpreting and applying the recommendations. There is significant content relating to the metrics of the current standards which has been reproduced with BSi permission.

CHAPTER 3 INDOOR WORKPLACES This chapter has been updated in line

with the revisions to BS EN 124641:2021 Light and Lighting of Work Places.

Part 1 – Indoor Work Places. There is additional commentary on some of the recommendations in the standard as well as inclusion of all 42 metrics tables by lighting application.

CHAPTER 4 OUTDOOR WORKPLACES Here the updates are in line with the revisions to BS EN 12464-2:2011 Light and Lighting of Work Places. Part 2 – Outdoor Work Places. There is additional commentary on some of the recommendations in the standard, information on environmental zoning and reducing light pollution, and inclusion of all 19 metrics tables by lighting application.

CHAPTER 5 ROAD This reflects the revisions to BS5489-1:2020 Code of Practice for the Design of Road Lighting and Public Amenity Areas, as well as the updates applied to BS EN 13201 parts 2,3,4 and 5 Road lighting, published in 2015. There are also comprehensive details on the application of these standards and links to further additional information.

CHAPTER 6 DAYLIGHT Here information has been revised in line with BS EN 17037:2018 Daylighting of Buildings. Daylighting is an important part of the lighting deliverable in the built environment and its quality is the benchmark standard that electric lighting should aspire to. However, working with daylighting involves taking into account many variables not encountered with fixed electric lighting. This chapter explains the nature of those variables and how to manage them.

CHAPTER 7 ENERGY AND ELECTRIC LIGHTING This explains why lighting energy is a significant consideration when lighting in a sustainable way and why it is important to support the decarbonisation of the built environment while maintaining the quality of delivered light. The method of calculating lighting energy in use is accurately modelled in BS EN 15193-1+A1:2021

sll.org.uk

Guidance

March/April 2022

cylindrical, semi-cylindrical, spherical and hemispherical illuminance.

Donal Murphy Photo

CHAPTER 12 INDIRECT LIGHTING So what happens when the light source is directed towards a surface such as a ceiling and the lighting solution is dependent on surface reflectances? This chapter covers the theory and application of Sumpners method, transfer factors and form factors.

Here you will find a good example of how a lighting method can confuse softwarebased design tools, due to the complexity of modern surface coverings, and why there is a need to know your first principles to validate your design.

BDP's scheme for Rothco/Accenture Dublin office challenges lighting conventions with details such as circulation lighting from furniture. Chapter 12 examines indirect lighting and what happens when the solution is dependent on surface reflectances

Energy Performance of Buildings. Energy Requirements for Lighting. Specifications, Module M9 . This is further applied to the Building Regulations example based on the current and most up-to-date Building Regulations Approved Document L, the conservation of fuel and power in buildings for England (see p9).

There is also reference to optional energy certifications outside of the Building Regulations such as BREEAM, LEED and NABERS. CHAPTER 8 CDM 2015 REGULATIONS Here the Code explains the Construction Design Management legislation in respect of lighting schemes and its relevance to lighting projects. It also explains the obligations of clients, principal designers, designers, principal contractors, contractors, manufacturers and workers.

The following chapters cover the first principles of lighting physics and calculations and also explain the relevance to lighting applications. The first principles have mostly remained constant since 2011/12 but in

Twitter: @sll100

some cases the impact of light source technology adaption had to be factored into some chapters.

CHAPTER 9 BASIC ENERGY AND LIGHT This covers light as a part of the electromagnetic spectrum, the energy contained within light, how light behaves, spectral and photopic light, and the only, but significant, addition – the melanopic or non-visual component of light.

CHAPTER 10 LUMINOUS FLUX, INTENSITY, ILLUMINANCE, LUMINANCE AND THEIR RELATIONSHIP Do you know the difference between illuminance and luminance? This chapter will provide the answers.

CHAPTER 11 DIRECT LIGHTING Ever wondered about the less obvious characteristics of light sources fixed to a ceiling and that point downwards? This chapter covers point, line and area light sources and the additional benefits of

CHAPTER 13 PHOTOMETRIC DATA SHEETS Did you know that there is a series of BS EN standards that recommend how photometric data sheets are created and compiled? This chapter explores the BS EN 13032 series of standards and will provide useful first principle information on how a comprehensive and accurate data sheet should be written.

CHAPTER 14 INDOOR LIGHTING CALCULATIONS There is a lot more to indoor lighting calculations than just measuring the horizontal illuminance on a defined task area some distance above the floor, and what happens when there is more than one light source required to light a space. The first principles of lighting in a more realistic spatial environment are detailed, and how to derive illumination values such as Planar, scalar, hemispherical, cylindrical and semicylindrical illuminances.

CHAPTER 15 OUTDOOR LIGHTING CALCULATIONS Outdoor lighting calculations are not indoor lighting calculations. Here the focus is mostly on road lighting scenarios, as this is perhaps the most important type of outdoor lighting in terms of safety, relative to the number of users. There is information on how to determine glare, how surface reflectance can change, and where the previously mentioned terms semi-cylindrical and semi-spherical illuminances are important.

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CHAPTER 16 MEASUREMENT OF LIGHTING INSTALLATIONS AND INTERPRETING THE RESULTS This details how to measure light output of the completed lighting installation that you may have designed or been asked to verify. It’s clear from the outset that an app on a mobile phone won’t cut the mustard here. The specifications for illuminance and luminance meters are covered, plus operating conditions under which measurements can be made. Grids and illuminance measurement, measuring of road luminance and measuring spatial illuminances are covered in chapters 13 and 15.

CHAPTER 18 PREDICTING MAINTENANCE FACTOR We have all seen lighting designs with an MF of 0.8, but why is this so? This chapter explains how maintenance factor for both indoor and outdoor lighting can be calculated and, more importantly, how to explain the reason why an MF other than 0.8 is being proposed.

CHAPTER 17 COLOUR The chapter is divided into two sections in order to explore the two critical factors that will help deliver colour in the way the designer wishes the viewer to perceive objects, both animate and inanimate.

CHAPTER 19 GLOSSARY OF TERMS Like most subjects, lighting loves a good acronym or obtuse term. This chapter lists all the acronyms and terms used in the SLL Code and provides explanations and/or definitions.

• Colour properties of light sources This concerns chromaticity, colour temperature, colour rendering and the different methods for determining rendering, for example, CRI, Colour

CHAPTER 20 APPENDICES This basically comprises a comprehensive list and referencing of all external legislation, standards, technical papers and

'Like most subjects at a professional level, you think you know all about the subject until you really need to go deeper to find the answers'

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Quality Scale (CQS) and the IES TM 3020 model.

• Colour properties of surfaces This details the Munsell system, natural colour system (NCS) DIN system, BS 5252, RAL and CIE L*a*b* methods.

Sophie Parry is technical application and training consultant and sustainability ambassador for Zumtobel Group Lighting UK and Ireland. She is also the chair of the SLL's technical and publications committee and a member of BSi Committee CPL/34/4 Luminaires

guidance documents used in the SLL Code.

This has been a large project for the SLL’s technical and publications committee and there have also been contributions from other SLL members and non-members.

The project has been ongoing for several years, but reached a critical point early in 2021 where there was enough update material created to justify bringing this project to a conclusion and while all the information in the SLL Code is still current.

The latest version of the SLL Code for Lighting is scheduled for publication in the first half of this year. Go to www.cibse. org/society-of-light-and-lighting-sll/sllpublications-and-guidance

Project manager and editor-in-chief Sophie Parry, MIET FSLL Chapter authors and principal contributors Allan Howard, BEng (Hons) FLIP FSLL, group technical director (lighting), WSP Ruth Kelly-Waskett, PhD CEng MCIBSE FSLL, senior associate at Hoare Lea and current SLL president Sophie Parry Professor Peter Raynham, CEng MSc MCIBSE FILP FSLL, UCL Institute for Environmental Design Engineering Peter Thorns, CEng BSc (Hons) FCIBSE FSLL, head of strategic lighting applications, Thorn Lighting, ZGL Contributors and reviewers Professor Steve Fotios, PhD CEng MEI MILP FSLL, University of Sheffield Nigel Monaghan, FSLL, senior lighting consultant, Luminous Solutions Peter Raynham Peter Thorns Technical secretary John Fitzpatrick, SLL technical and publications committee Editor Ken Butcher, CIBSE Publications

sll.org.uk

Regulations

March/April 2022

TOWARDS NET ZERO

Volume 1 for dwellings and Volume 2 for buildings other than dwellings. The separate compliance guides, which contained the technical criteria for compliance, have also gone, with all technical information now contained within the two volumes. Each volume also provides guidance for both new buildings and work in existing buildings.

Lighting is considered as a fixed building service and is therefore required to be energy efficient, have effective controls and be commissioned to ensure that it uses no more fuel and power than is reasonable in the circumstances. Section 6 of both volumes deals with lighting and lays out the minimum performance requirements.

The UK government has published the latest edition of Approved Document L, the conservation of fuel and power in buildings for England. Richard Caple reviews the changes to the lighting requirements

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his new two-volume edition of Approved Document L is significant as it is the next step on the UK’s journey to reaching net zero greenhouse gas emissions by 2050.

For dwellings, the changes are seen as a stepping stone to the Future Homes Standard, due in 2025, where homes will be required to produce up to 80 per cent less carbon emissions compared with homes built under the 2013 requirements.

To bridge the gap between now and 2025, the changes mean homes will be required to produce 31 per cent less carbon emissions.

The greatest impact of these changes will be felt in the heating, insulation and air tightness requirements. Interestingly, the consultation on the Future Buildings Standard, which covers non-domestic buildings, only focused on the requirements for 2021, with no targets set for 2025 as with the Future Homes Standard.

Although published in December 2021, the regulations and guidance don’t take effect until 15 June 2022. Even then, they will not apply for work that is subject to a building notice, where full plans are in application or an initial notice has been submitted before this date, and provided that work has commenced on site before 15 June 2023.

In an effort to simplify the Approved Documents, the first notable change is that there are now two documents as opposed to six. Previously there were separate ones for dwellings known as the L1 documents, and buildings other than dwellings, L2 .

There were also A and B versions of each which covered new buildings or work in existing buildings. In addition to this there were also two compliance guides with each one covering each building type. Thankfully it is now much simpler. There are now two volumes of Approved Document L,

LIGHTING WITHIN DWELLINGS Changes to the lighting criteria have made the energy performance requirements more stringent, but also simpler.

Importantly, reference is made to achieving appropriate light levels for the activity, but it also emphasises that a space should not be overlit. It does, however, acknowledge that in many cases householders will select their own lamp.

The requirement for three out of four light fittings to be low energy has been removed. Now all fixed internal lighting for both new builds and work in existing buildings must use lamps with a minimum luminous efficacy of 75 light source lumens per circuit watt, regardless of the amount of light it is producing (previously it was 45 lamp lumens per circuit-watt for light sources over 400 lamp lumens).

Where fixed external lighting is concerned there is no longer any differentiation between lamps over or under 100 lamp-watts. However, luminaires with an efficacy of less than 75 light source lumens per circuit-watt must use automatic controls that switch the luminaires off once the area becomes unoccupied. For luminaires with an efficacy greater than 75 light source lumens per circuit-watt, manual control can still be used.

Pershore college, near Evesham: energy saving through daylight linking

Thorlux Lighting

LIGHTING WITHIN BUILDINGS OTHER THAN DWELLINGS

Twitter: @sll100

As with dwellings, the changes to buildings other than dwellings have a similar theme: simpler, but more stringent. There are still two options of demonstrating lighting compliance, which can be done through

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either meeting the minimum lighting efficacy requirements or by following the Lighting Energy Numeric Indicator (Leni) method. This is the alternative method first introduced in 2013 which calculates the total lighting energy per square metre per year (kWh per square metre per year).

For this edition, there has been little change to the Leni requirements. The calculation formula has remained untouched with the only change being to the Leni values themselves, which brings them in line with the changes to the minimum lighting efficacy requirements that are described later on.

For the first time, there is also reference to illumination levels. While no values are quoted, it mentions the importance of achieving appropriate levels of illumination for the activity in the space, but also highlights that spaces should not be overlit.

To ensure that spaces are illuminated appropriately, it also states that lighting should be designed based on guidance provided in the SLL Lighting Handbook or equivalent. There is an additional note that for smaller spaces such as toilets or store rooms, where power consumption is likely to be very low, there is no expectation that lighting calculations should be produced.

The minimum standards recommended only apply to the general or display lighting within buildings. The guidance does not set out standards for exterior or specialist lighting such as that relevant to theatrical, stage or projector applications.

GENERAL LIGHTING CHANGES To comply with the general lighting requirements, lighting is required to either: 1

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Have an average luminaire efficacy of 95 luminaire lumens per circuit-watt OR Comply with the Leni method calculation

This is a simplified approach as previously general lighting was split into two types, ‘office, industrial and storage areas’, and ‘other types of space’ with differing requirements for each. Now all lighting within a building is considered as one type, ‘general lighting’, with the exception of ‘display lighting’ which still has its own requirements and is covered later on. Table 1

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Table 1: the differences between the 2013 and 2021 general lighting requirements

Table 2: the differences between the 2013 and 2021 display lighting requirements

details the differences between the 2013 and 2021 general lighting requirements.

The increase in recommended minimum luminaire efficacy is considerable, rising from 60 to 95 luminaire lumens per circuitwatt, a 60 per cent increase. This was not unexpected. With LED technology now widely adopted across all areas of a building, and luminaire efficacies typically in excess of 100 luminaire lumens per circuit-watt, many would argue that this new value might not go far enough.

However, a one-size-fits-all metric can be problematic, and it should be noted that this requirement remains an average across the building, rather than a measure for each individual luminaire type used. This means that in some areas, where more decorative and less efficient luminaires are required, or spaces that are small and inherently less efficient, such as toilets and store rooms, a balance can be struck by offsetting lower efficacy luminaires with higher ones.

One of the other significant changes is the removal of the controls factor when calculating the recommended minimum lighting efficacy. Previously a factor could be applied when using energy-saving controls such as presence detectors or an energy-saving control system, for example.

Depending on the type of system used, a factor could be applied to the calculation which lowered the required minimum luminaire efficacy, in some cases to as low

as 42 luminaire lumens per circuit-watt, allowing for the use of significantly less efficient luminaires.

The controls factor was introduced to advocate and encourage the use of lighting controls. Even though lower efficacy luminaires could be used, the energy savings provided by a control system far outweighed this. With this removed, the 95 luminaire lumens per circuit-watt requirement is now regardless of whether any energy-saving systems are being used.

Lighting Handbook The SLL Lighting Handbook contains 32 chapters of extensive guidance and best practice to help anyone in the process of lighting design. Lighting forms a vital part of our built environment, allowing us to work well, to see the buildings and spaces around us and to escape safely from buildings when the need arises.

All of this must be achieved with energy conservation in mind. Guidance within Approved Document L recommends lighting designs are based on the SLL Lighting Handbook. It can be purchased from the CIBSE Knowledge Portal or is free for SLL members: www.cibse.org/ knowledge/knowledge-items/ detail?id=a0q0O00000F4MeJQAV

sll.org.uk

Regulations

March/April 2022

DISPLAY LIGHTING CHANGES For display lighting the guidance includes three possible ways to demonstrate compliance: 1

2 3

Have an average light source efficacy of 80 light source lumens per circuit-watt OR Have a rated power usage of no more than 0.3W per sqm in each space OR Comply with the Leni method calculation

There are three changes here, the most significant being the increase in efficacy, rising from 22 to 80 light source lumens per watt. This is no doubt due to the adoption of LED technology in this area. The second difference is the term ‘light source lumens’ which replaces ‘lamp lumens’. While there is technically no difference between the Summary While there has been some tinkering around the edges in terms of increased performance requirements, on the whole this update is relatively minor.

It’s important to note that these changes only apply to England, although both Wales and Scotland are currently in the process of updating their respective regulations and guidance, with both due for publication this year. The status of Northern Ireland is currently unknown.

In the longer term, as we venture further down the road towards 2050 and net zero greenhouse gas emissions, we can be sure that greater energy efficiency and carbon reduction in our buildings is going to be required, putting further pressure on building services to become even more energy efficient.

While it is expected that much of the change will be in areas such as building fabric, heating/ cooling and air tightness, lighting will need to play its part. If we see requirements for luminaire efficacies of 120 or maybe even 140 luminaire lumens per circuit-watt, things could start to get really interesting.

Twitter: @sll100

two, a lamp is a light source, this change in terminology further acknowledges the market moving to LED technology.

The third amendment is the addition of the 0.3W per sqm limit per space. This simplified approach is ideal for smaller projects where there are perhaps just a few display lights here and there, or where the ‘light source lumens’ are unknown, not available or difficult to obtain. Table 2 details the differences between the 2013 and 2021 display lighting requirements.

While the controls factors have been removed from the calculation of minimum luminaire efficacy, which some might consider a de-valuing of energy-saving lighting controls, an entirely new section has been added making clear that energy-saving controls should be used where appropriate.

In addition to the recommendation that guidance provided in the Building Research Establishment’s Digest 498 for lighting controls in new and existing buildings is followed, it also specifically stipulates the use of automatic controls to turn the general lighting off in unoccupied spaces or when the occupied space becomes vacant.

Daylight-linked controls that either switch or dim the luminaires should also be used in

occupied spaces, where there is a likelihood of high daylight levels.

While previously there was ‘encouragement’ to use energy-saving controls, it’s a relief that there is now clear guidance that they should be used. Despite falling lighting loads due to the increasing efficacy of LED luminaires, huge energy savings can still be made by investing in controls. After all, the most efficient light fitting is the one that is switched off.

Richard Caple, FSLL, is a past president of the SLL, and marketing and lighting applications director at Thorlux Lighting

Terminology Luminaire lumens Equal to (light source lumens x light output ratio) and represents the output of the luminaire. Light output ratio (LOR) is the ratio of the output of the luminaire at stated practical conditions to that of the lamp(s) contained in the luminaire under reference conditions Light source lumens The sum of the average initial (100-hour) lumen output of all the light sources in a luminaire. Does not include any losses or inefficiencies of the luminaire Circuit-watt Refers to the power consumed in lighting circuits by lamps and, where applicable, their associated control gear (including transformers and drivers) and power factor correction equipment Display lighting Lighting to highlight displays of exhibits or merchandise, or lighting used in spaces for public leisure and entertainment, such as dance halls, auditoria, conference halls, restaurants and cinemas Lighting Energy Numeric Indicator (Leni) A measure of the performance of lighting in terms of energy per square metre per year (kWh/sqm per year) Fixed external lighting Lighting fixed to an external surface of the building and supplied from the occupier’s electrical system. It excludes lighting in common areas of blocks of flats and in other communal accessways

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Guidance

March/April 2022

The SLL's latest guide to emergency lighting is now available. David Mooney explains why the updates reflect a fundamental shift in emphasis

T

he 2022 version of Lighting Guide 12: Emergency Lighting has just been published. Many people have asked me why a new edition was necessary. There are a number of reasons, mainly relating to advances in technology, changing legislation and BS EN standards that are not covered in the previous 2015 version.

It is the policy of the SLL to regularly review and, where necessary, update guidance publications on a maximum fiveyearly basis, usually for the three reasons outlined above.

It is clear from my own work that

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the level of compliance with emergency lighting standards is lacking. My own company surveys a huge number of existing emergency lighting installations and it's rare that we don't discover issues with them.

Typically they relate to installation defects, a lack of maintenance or incomplete documentation.

The BSI issued a new version of BS EN 5266-1 in 2016 with some quite radical changes in its guidance, such as the addition of emergency safety lighting. Emergency lighting technology is changing rapidly with the introduction of LEDs, new battery types, automatic testing and monitoring

Shuttertock

EXIT STRATEGY systems, and wireless technology. Some of these technologies are still in an early stage of development and therefore standards and guidance are not always able to remain current with the rate of change of technological development.

It is worth reminding ourselves of two fundamental points: 1

Emergency lighting is a statutory requirement covered by the Health and Safety at Work Act which states that: 'Emergency lighting should be safe and sufficient'. Emergency lighting is primarily installed to cover the loss of electrical power within a building and sometimes to adjacent external escape routes. It is therefore required to aid occupants in either evacuation from the building or to enable them to continue critical tasks during a lighting failure.

sll.org.uk

Guidance

March/April 2022

2

Emergency lighting has historical links with fire safety, but it is not primarily a fire-safety system. However, it is a life-safety system. Emergency lighting also has to support fire-safety systems where appropriate, as a fire situation can also mean there is a loss of power to the general lighting circuits.

Think of it like this: building occupants may have to safely escape from a fire situation to a safe place when the emergency lighting is the sole means of safe illumination.

Just another collection of technical principles? Yes and no…

The revised guide now includes a fundamental change in emphasis, which covers the delivery of emergency lighting installations rather than just the technical principles of emergency lighting.

Technical principles are obviously important and are also included, but compliant emergency lighting also requires a strategic approach to design, specification and the operational lifecycle.

The guide supports the emergency lighting professional in managing the information flow from project inception through to disposal and replacement of the system. It also aids building professionals in their understanding of the information flow enabling them to deliver a compliant emergency lighting scheme.

In addition, the revised guide looks at approaches to the wide range of buildings that will require emergency lighting, which could range from a scout hut to an airport.

It seeks to clarify the type of emergency lighting, and the design and delivery approach, appropriate to the size and complexity of the project.

CHANGING TIMES Changes in the regulatory framework, including imminent publication of the UK government’s new Building Safety Bill, will bring additional emphasis to the correct delivery of all building safety systems, including emergency lighting.

Definitions of competency will also be part of the anticipated regulatory framework and should also be noted.

Although there are no direct competency standards for emergency lighting at the time of writing, general competency

principles should be followed as outlined in BS Flex 8670. In the near future, it is likely that competency statements will need to be provided to clients by all building professionals on a project-by-project basis.

Consultants and contractors may be required to introduce their own competency framework to manage emergency lighting products, design, installation and operation. Model transfer certificates covering design and installation through to commissioning and handover, as well as surveys and maintenance, already exist in BS EN 5266-1 appendix H but are not often requested in the UK. This ‘certificate trail’, especially for design, is likely to become more commonplace in the UK. It is already routine in Ireland, and the competency level of the EM designer is defined as either a CEng or an EM designer who has been on an approved three-day course and passed the exam.

The guide examines the current best practice guidance for emergency lighting issued by the BSI and other organisations.

It is important to understand that the standards are not regulations but form the starting point for which designs, and projects, will have their own unique considerations and will need risk assessing to ensure 'a safe and sufficient' installation.

However, for many years now, the entire building fire-risk assessments that in turn inform compliant emergency lighting must be led by the client, their fire risk assessor and/or architect. Additionally, and if requested, with support from an emergency lighting professional.

Risk Assessments are identified in BS 5266 Pt 1 and are not the exception, they are the norm. For smaller projects the emergency lighting risk assessment may form part of the fire-risk assessment. The ability to undertake a risk assessment will be a competency issue in itself. Ultimately it is the role of the client’s 'responsible person’ to ensure the emergency lighting

system is compliant with legislation and the building’s assessed whole building fire plan/ risk assessment.

As part of the trend towards competency validation in the near future, it is expected that there will be renewed emphasis on whole-building fire-risk assessments and, in particular, the section concerning emergency lighting.

In conclusion, emergency lighting isn’t a particularly difficult area of design, but there is a wide range of information that has to be gathered from various parties before a compliant emergency lighting design can begin. Emergency lighting is an information management conundrum and there will be a number of emergency lighting professionals employed by the client during a project’s lifetime.

Those professionals need to take the lead to ensure that the correct information is provided at the right time and be ready to handover the scheme to the next lead professional up to operation and disposal phases. Emergency lighting isn’t changing fundamentally but it is going to become a more regulated area of building design and there will be a more formal method of demonstrating compliance.

David Mooney, FSLL, is an associate at Atkins and the author of LG12 Lighting Guide 12: Emergency Lighting is free to CIBSE/SLL members in PDF format. It can now be downloaded at: www.cibse.org/society-of-light-andlighting-sll/sll-publications-andguidance

'It is not primarily a fire safety system. However, it is a life safety system'

Twitter: @sll100

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Obituaries

March/April 2022

OBITUARIES

2021 sadly saw the loss of two more SLL past presidents, Robert Bean and Ken Ackerman DR ROBERT BEAN CEng FCIBSE FSLL

President of the CIBSE Lighting Division, the forerunner of the SLL, in 1979, Robert (Bob) Bean was made an honorary fellow of the SLL in 2014. He joined as a member of the IES UK in 1964.

Initially he worked for the lighting engineering department of Atlas Lighting in the 1950s before switching to academia. For many years he taught at the Chelmer Institute of Higher Education in Chelmsford, now part of Anglia Ruskin University.

According to David Loe, in the 1960s Bob Bean was the first in Britain to provide education on illumination considering lighting equipment, photometry and lamp performance. In the 1970s he and Bob Bell of Thorn developed the flux transfer method for calculating utilisation factors using matrices.

He wrote two books with Ron Simons regarded as classics in their field: Lighting Engineering: Applied Calculations (Simons and

KEN ACKERMAN BSc (Eng) CEng FIEE FILLumES

Ken Ackerman, was president of the CIBSE Lighting Division in 1975.

The substantial part of his professional career was spent in television lighting with the BBC. He wrote several papers for LR&T, including Lighting for colour television (1969) and Light and Communication (1975, the basis of his presidential address).

He will also be remembered for his research with Prof Einhorn in South Africa, developing the concept of sector flux, and for his work on interior lighting prediction (interreflections) with Harold Bellchambers at British ThomsonHouston in Rugby, which as well as other electrical products made Mazda lamps.

In more recent years he became more involved in CIBSE and the CIE technical committee, promoting and organising the Showlight Exhibition.

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Bean, 2008) and Lighting Fittings Performance and Design (Bean and Simons, 2014), and before those, Lighting: Interior and Exterior (2003). He also published a number of papers in Lighting Research and Technology, and was a member of the editorial board.

'When I wanted to know anything about lighting calculations or luminaires he was the man to go to,' said former LR&T editor Peter Boyce. 'He was always kind, courteous and generous with his time, even to the most ignorant questioner.'

Former president Alan Tulla, who met Bean when he first joined the then Lighting Division, echoed the sentiment. 'He was always very helpful whenever I asked him a question, no matter how dumb. He was a really nice man and his amiability hid a sharp mind even in his later years.'

He was also a Methodist minister, known as the Reverend Doctor Robert Bean, and was based in Berkhampstead.

'He was a real gentleman,' said another past president, Kevin Kelly.

'He was a person of distinction with the manners of a true gentleman,' said Geoff Cook, who met him through the CIE-UK Committee.

'He was very helpful to me during my early days in the CIE world of light and lighting.

Although a man of few words, those that he chose to use were reasoned, effective and always polite. The SLL and the wider lighting community has lost a highly valued member.'

'He was a giant in the industry,' said another past president Bob Venning.

'Although a man of few words, those that he chose to use were reasoned, effective and always polite'

sll.org.uk

LR&T essentials

March/April 2022

FINE TUNING L

ia et al present a study investigating highly photosensitive artworks (HPAs) and the colour damage that can be caused by the spectral energy radiated by light sources. The authors note that spectral power distributions (SPD) differ according to the type of light source, and that the absorption and reflection of different materials also varies. These differences between light source SPDs and material absorption and reflection properties could result in large variations in the degree of radiation damage of a material under the same light intensity.

In an experiment conducted over 90 days, 10 different narrow-band light sources were used to illuminate nine different HPA materials for 16 hours a day. From an analysis of colour difference data of the illuminated material against the amount of exposure, a mathematical model was developed to predict damage to the colour of an HPA under the specific spectral composition of a light source.

This enabled an accurate judgement of light sources for the illumination of HPAs to be made, according to the authors.

Also on a spectral theme, with the increasing use of LEDs for colour tunability, Eissfeldt and Khanh have developed an algorithm for real-time colour mixing of a five-channel LED system while optimising the spectral quality parameters.

They note that multichannel LED luminaires with more than three channels give the advantage of being able to vary the spectrum and keep the chromaticity steady. They also note, however, that various quality metric optimisation calculations are a challenge to implement due to the potentially limited resources of a luminaire’s microcontroller.

They have therefore developed a method in which a five-channel system is simulated with

Iain Carlile finds colour among a spectrum of subjects in the latest Lighting Research and Technology papers

a quickly solvable three-channel system by defining virtual channels, each consisting of two LED channels.

This allows the algorithm to be calculated quickly in real-time without high hardware requirements. The algorithm allows various light quality characteristics (colour fidelity index, visual metamerism index, melanopic radiance, melanopic efficacy, and maximum achievable luminance), to be set in order to optimise the mixing of the five LEDs. The ability to easily calculate the algorithm could allow for sensor feedback to be quickly calculated allowing the light output of the five different LED channels to be easily adjusted in real time. An example would be a luminaire that could adapt its SPD to ambient light in real-time to optimise colour rendering for a particular task.

Batool et al have investigated view preference in natural and urban environments.

An experiment was undertaken in which participants looked at images of natural scenes.

Subjective preference ratings and eye-tracking data were recorded when viewing scenes, with qualitative data providing insight to the inferences from the quantitative data. From the results the authors concluded that: •

•

Natural views are preferred to urban views, with preference moderated by different environmental cues such as the presence of people, colours, mountains, trees, water, and so on.

Environments perceived as inhospitable or threatening to humans were often least preferred.

Gaze behaviour depends on view type and view preference. Gaze behaviour differed significantly based on whether the scene was natural or urban, with natural scenes leading

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) Evaluation methodology for light sources used to illuminate highly photosensitive artwork Z Lia, F Zhang, X Song and R Dang Algorithm for real-time colour mixing of a five-channel LED system while optimising spectral quality parameters A Eissfeldt and TQ Khanh Gaze correlates of view preference: Comparing natural and urban scenes A Batool, P Rutherford, P McGraw, T Ledgeway and S Altomonte

•

to a lower number of fixations and saccades (quick, simultaneous movements of both eyes between two or more phases of fixation in the same direction).

Participants’ perceived relationship with nature is related to gaze behaviour, with individuals' scores of nature relatedness being positively correlated with a more exploratory oculomotor response while viewing natural scenes.

From the findings it is suggested that individual preferences and personality attributes should be accounted for in further studies on view preference and gaze behaviour.

Colour change of nine materials with exposure to 447nm narrow-band illumination (Lia et al)

Twitter: @sll100

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

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Events 2022

For details of all upcoming webinars, go to: www.cibse.org/society-oflight-and-lighting-sll/sll-events/upcoming-webinars-and-online-content For previously recorded CPD webinars (including regional webinars), go to: www.cibse.org/society-of-light-and-lighting-sll/sll-events/pastpresentations

EVENTS SLL AGM, PRESIDENTIAL ADDRESS AND AGM Venue: Manchester and online Date: 26 May LIGHT + BUILDING 2022 Venue: Messe Frankfurt Date: 2-6 October www.light-building.com

ONLINE EVENT RESPONSIBLE OUTDOOR LIGHTING AT NIGHT (ROLAN) (Organised by Dr Karolina Zielinska-Dabkowska with the SLL and involving other relevant bodies) Date: 12-13 May www.sll.org.uk

AVAILABLE WEBINARS INCLUDE EXTERIOR LIGHTING FOR PEOPLE (SLL and CIBSE Home Counties North West) Speaker: Steve Fotios, professor of lighting and visual perception at the University of Sheffield Chair: Chris Dicks, SLL regional representative Steve Fotios discusses what is meant by safety, distinguishing between the measurable effects of lighting a space and people's perception of safety SLL IN CONVERSATION WITH ANDREW BISSELL AND CHRISTOPHER KYBA (SLL and Signify) Andrew Bissell, FSLL, SLL president-elect and director of lighting design for Cundall, and leading research scientist Dr Christopher Kyba discuss ongoing work to produce more robust guidance for the protection of dark skies and research into the causes and effects of skyglow INDOOR LIGHTING: CHANGE IS AFOOT (SLL and CIBSE Ireland) Looking at the newly revised BS EN 12464-1:2021 Light and Lighting of Work Places. Part 1. Indoor Workplaces, launched last autumn.

Speaker: Sophie Parry, FSLL, technical applications consultant for ZG Group UK and Ireland, and chair of the SLL technical and publications committee

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