Mastering Modern Lighting Design: A Guide to the SLL Lighting Handbook (2018)

Introduction

Lighting is one of the most fundamental elements of the built environment. It shapes how we see, feel, and interact with the spaces we occupy—whether at work, at home, in healthcare facilities, or in public spaces. Good lighting design enhances productivity, improves wellbeing, supports safety and security, and can transform a building’s architecture.

In 2018, the Society of Light and Lighting (SLL)—part of the Chartered Institution of Building Services Engineers (CIBSE)—released a completely rewritten and expanded edition of the SLL Lighting Handbook. Building on the success of the 2009 centenary edition, this updated version is 50% bigger, with 34 chapters and four appendices spanning some 480 pages. It is designed to guide lighting professionals—known in the industry as “lighters”—from initial design decisions through to commissioning and maintenance of a successful lighting scheme.

This article provides an overview of the handbook’s key themes and new content, and explains why it is an essential reference for anyone working in the field.

Free to download for CIBSE members—and available at a standard rate for non-members—the SLL Lighting Handbook is the first-stop reference for lighting design, technology, and applications.

Part 1: Fundamentals – A Structured Approach to Lighting Design

The first section of the handbook covers the essential principles of lighting design and includes three completely new chapters that provide a firm foundation for modern lighting practice.

Lighting Design Process

Before any technical decisions are made, a designer must understand the objectives, the people who will use the space, and the issues that will shape the design. The new Lighting Design Process chapter asks fundamental questions: Why is the lighting needed? Who is it for? What does the client want the lighting to achieve? These questions are the starting point for a structured process that moves from initial brief through concept and technical design to construction, handover, and post-occupancy evaluation.

Crucially, the chapter reminds us that lighting is not just about meeting a numerical illuminance target. It is about creating a safe, legible, and comfortable environment that supports the activities and experience of the people using the space.

Design Ethos

The Design Ethos chapter builds on the CIBSE Code of Conduct and sets out the professional and ethical responsibilities of lighting designers. These include considerations around tendering procedures, the Bribery Act, the responsibilities of specifying “equal and approved” products, and the importance of sustainability. The chapter reinforces that lighting professionals have a duty to wider society, not just to their immediate client.

Coordination with Other Services

Lighting design does not happen in isolation. The Coordination with Other Services chapter has been introduced to help those from non-engineering backgrounds—such as architects, interior designers, and theatre designers—understand the practical realities of coordinating lighting with other building services.

The chapter covers the hierarchy of services in ceiling voids, how to integrate lighting with air conditioning systems, and the importance of providing space for power cabling and control wiring. It is a valuable reminder that the best lighting design is one that can be successfully installed and maintained without conflict with other building systems.

Daylighting and Emergency Lighting

The fundamentals section also includes detailed chapters on Daylighting and Emergency Lighting. The daylighting chapter covers the many benefits of natural light—energy savings, occupant health and wellbeing, and aesthetics—as well as the need to control glare, solar gain, and contrast. The emergency lighting chapter provides guidance on legislation, standards, design approaches, and system planning, ensuring that safety is always a priority.

Part 2: Technology – Keeping Pace with Rapid Change

The technology section has been comprehensively updated to reflect the rapid changes in lighting technology over the past decade, particularly the rise of LEDs and digital controls.

Light Sources

The new Light Sources chapter covers the full spectrum of modern lighting technology, with a significant focus on LEDs. It explains the construction of LEDs, their directionality, the type of light they emit, and their temperature sensitivity—noting that heat dissipation is critical to maintaining light output and lifespan.

Crucially, the handbook does not abandon traditional technologies. It also covers metal halide lamps, discharge lamps, and even gas lighting, ensuring that practitioners have the knowledge to work with the full range of existing installations.

Control Gear

The Control Gear chapter covers transformers, electronic control gear for fluorescent and discharge lamps, and the specialised control gear required for LED and OLED sources. It also includes sections on emergency lighting control gear, inrush current considerations, and control gear for circadian lighting—an area of growing importance in healthcare and wellbeing-focused design.

Controls

The Controls chapter has been significantly expanded to address the growing demand for energy-efficient and responsive lighting systems. The handbook notes that controls are “essential” for compliance with current Building Regulations and energy performance requirements, but warns that “lighting performance should not be compromised in the sole interests of energy conservation”.

The chapter covers dimming, regulation, application examples, and the basis of a lighting control design. It also addresses control for visual effects, circadian lighting, and automatic testing and monitoring of emergency lighting.

Power to Lighting Systems

The entirely new Power to Lighting Systems chapter reflects the growing importance of power distribution and connectivity to modern lighting design. It is not an electrical engineering chapter, but it outlines the circuit design process and describes how cables are installed and routed through the building.

The chapter includes a salient reminder: no matter how complex the design, there are two basic requirements—the safety of people and ensuring that the risk of fire is not introduced. It covers conventional and modular cabling systems, connection methods, distributed power, direct current power supplies, and Power over Ethernet (PoE).

Part 3: Applications – Comprehensive Guidance for Every Space

The applications section forms the bulk of the handbook, with 22 chapters covering a wide range of interior and exterior environments. Several of these are entirely new to the 2018 edition, reflecting the evolving needs of the industry.

Common Building Areas

The new Common Building Areas chapter provides practical guidance for the generic spaces found in almost every building—entrance halls, reception desks, corridors, stairs, toilets, tea points, cleaners’ rooms, store rooms, and plant rooms.

What makes this chapter so valuable is its granularity. For example, toilets were previously only designated as requiring 100 lux, with no guidance on where to measure. The new chapter provides recommended lighting levels for the floor, basins and surrounding surfaces, at toilet seat level, and over baby changing tables.

Similarly, the chapter provides detailed guidance for connecting spaces such as ramps, noting that where ramps form part of an exit route, emergency lighting should be provided with additional emphasis on the start and stop of the incline. It also drills down to the practical needs of cleaners’ rooms—such as providing light on the sink even when someone is leaning over it, and vertical illumination on shelving.

This level of practical detail has been welcomed by the industry and is expected to inform future European standards.

Specialised Building Types

The handbook includes entirely new chapters on Courts and Custodial Buildings and Extreme Environments.

The courts chapter provides guidance on lighting for a range of areas, including courtrooms, cells, and secure corridors, and accounts for wellbeing, security, and safety for inmates, staff, and visitors. It notes the importance of lighting resilience and the need for electronic control systems not to be susceptible to hacking.

The Extreme Environments chapter covers cold and freezing environments, hot and humid conditions, dusty environments, explosive environments, and marine environments—a potpourri of conditions that can apply to applications ranging from Antarctic research stations to flour mills and laundries.

Heritage and Exterior Lighting

The Historic Buildings and Spaces chapter provides guidance for four categories: historic buildings being converted to a new use, reuse of historic interiors, historic buildings preserved “as is,” and historic or sensitive exterior spaces such as world heritage city streets and gardens around historic buildings.

The Exterior Architectural Lighting chapter is entirely new and reflects the rapid development of this field, driven by the versatility and controllability of LEDs. It covers many ways to integrate lighting into façades, techniques for full or partial floodlighting, and practical guidance for lighting old frontages.

Exterior Workplaces, Roads, and Security Lighting

The handbook also provides comprehensive guidance on Exterior Workplaces, Roads and Urban Spaces, and Security Lighting. The exterior workplaces chapter covers open spaces such as goods yards and more localised areas such as loading docks and maintenance areas.

The road lighting chapter emphasises the importance of lighting not just the traffic parts of our roads but also pedestrian areas, surrounding buildings, verges, and landscape. The security lighting chapter addresses the positioning of lighting in relation to security staff and potential intruders, and notes that the handbook looks at commissioning and maintenance to ensure exterior systems retain their output and aim.

Commissioning and Performance Verification

Two other important new chapters are Commissioning of Lighting Installations and Performance Verification. Commissioning is often relegated to the end of projects, but the handbook emphasises that the commissioning programme starts well before installation, with pre-design assessments, and runs continuously through to installation handover, operator training, and post-completion checks.

The performance verification chapter covers the need for verification, the competency of those undertaking measurements, instrumentation, methods of measurement, and measurement of illuminance, luminance, and reflectance. These are critical steps in ensuring that the installed lighting meets the design intent.

Appendices: Beyond the Basics

The four appendices provide additional in-depth information on key topics:

• Reflectance and Colour – An extremely well-illustrated guide on understanding and specifying reflectance and colour, including the use of Light Reflectance Value (LRV).
• Circadian Lighting – The latest thinking on how lighting can support the human circadian system, an area of growing importance in healthcare and wellbeing design.
• Building Regulations and Environmental Labelling Schemes – A summary of the regulatory landscape and key environmental assessment schemes that lighting designers must navigate.
• Glossary of Terms – A comprehensive list of lighting terminology, ensuring consistency and clarity in the industry.

Conclusion: An Essential Tool for the Lighting Professional

The 2018 edition of the SLL Lighting Handbook is a remarkable achievement, bringing together the expertise of dozens of volunteer authors and reviewers to create a unique, well-balanced reference that covers the considerations, technologies, processes, and practices that unite to deliver a successfully illuminated environment.

The handbook is not designed to be read from cover to cover, but to be dipped into as a first point of reference for specific topics. Whether you are a lighting designer, an electrical engineer, an architect, a facilities manager, or a student, the SLL Lighting Handbook provides the knowledge you need to make informed decisions at every stage of a lighting project.

This article summarises key concepts from the 'SLL Lighting Handbook (2018)' published by the Society of Light and Lighting (SLL), part of CIBSE.

Download the full free document here: SLL Lighting Handbook (2018) – PDF Download

The handbook is free to download for CIBSE members. Non-members can purchase the PDF or hard copy at the standard rate.

Disclaimer: This article provides a summary of the 'SLL Lighting Handbook (2018)' technical publication by the Society of Light and Lighting. While efforts have been made to accurately represent the content, please refer to the official document for complete technical details. Final design, specification, and implementation decisions should be made by qualified professionals in accordance with all applicable regulations and standards.