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  • PublisherCIBSE
  • Product CodeSLLCL
  • Number of pages342
  • Publication DateJul 2012
  • ISBN

SLLCL SLL Code for Lighting

CIBSE Members

PDF Format







PDF Format






SLLCL SLL Code for Lighting

For many years, the IES Code for Lighting was the de facto standard for lighting provision in the United Kingdom. However, in 2002, the Committee for European Standardisation (CEN) took on the task of providing lighting recommendations, and, since then the British Standards Institution has adopted the CEN recommendations for use in the United Kingdom. As a result, there are now a range of British Standards that specify the quantitative lighting requirements for a wide range of applications. Consequently, the role of the SLL Code for Lighting has shifted from being the only source for quantitative lighting recommendations to being a guide on how to interpret the British Standard recommendations and how to implement them in practice.

This edition of the SLL Code for Lighting takes the changes in lighting guidance a step further by a process of separation and concentration. The separation involves moving the details of vision, lighting technology and lighting applications into another publication, the SLL Lighting Handbook. The concentration occurs because this SLL Code for Lighting provides information on three fundamental matters of relevance to lighting practice. These matters are:

  • A summary of what is known about the effects of lighting on task performance, behaviour, safety, perception and health as well as its financial and environmental costs.
  • A compendium of all the lighting recommendations relevant to the United Kingdom with suggestions as to how these should be interpreted. This compendium covers recommendations for both interior and exterior lighting in normal conditions.
  • A detailed description of all the calculations required for quantitative lighting design. While it is a fact that, today, most lighting calculations are done using software that simply implements the fundamental calculations described here, without knowledge of these calculations, it is diffi cult to assess the meaning and merit of the results produced by software.

First published in 1936, the Code for Lighting was published in printed form until 1994.  In 2002 the Code was published as a CD for the first time and the following editions in 2004, 2006 and 2009 were produced purely in CD format.  This 2012 edition reverts back to hard copy (and as a pdf), complimented by the SLL Lighting Handbook.


Chapter 1: The balance of lighting

1.1 Lighting quality
1.2 The place of lighting in the modern world
1.3 An overview of the effects of light on human performance
1.4 Lighting and visual task performance
1.4.1 Visual performance
1.4.2 Visual search
1.4.3 Mesopic conditions
1.4.4 A discrepancy
1.4.5 Improving visual performance
1.5 Lighting and behaviour
1.5.1 Attracting attention
1.5.2 Directing movement
1.5.3 Communication
1.6 Lighting and safety
1.6.1 Emergency escape lighting
1.6.2 Road lighting
1.6.3 Lighting and crime
1.7 Lighting and perception
1.7.1 Brightness
1.7.2 Form
1.7.3 Higher order perceptions
1.8 Lighting and health
1.8.1 Eyestrain
1.8.2 Non-visual effects
1.8.3 Tissue damage by optical radiation
1.9 Lighting costs
1.9.1 Financial costs
1.9.2 Electricity consumption
1.9.3 Chemical pollution
1.9.4 Light pollution
1.10 The future

Chapter 2: Indoor workplaces

2.1 Lighting design criteria
2.1.1 Luminous environment
2.1.2 Luminance distribution
2.1.3 Illuminance
2.1.4 Illuminance grid
2.1.5 Glare
2.1.6 Lighting in the interior space
2.1.7 Colour aspects
2.1.8 Flicker and stroboscopic effects
2.1.9 Lighting of work stations with display screen equipment (DSE)
2.1.10 Maintenance factor
2.1.11 Energy efficiency requirements
2.1.12 Additional benefits of daylight
2.1.13 Variability of light
2.2 Schedule of lighting requirements
2.2.1 Composition of the tables
2.2.2 Schedule of interior areas, tasks and activities
2.2.3 Verification procedures

Chapter 3: Outdoor workplaces

3.1 Lighting design criteria
3.1.1 Luminous environment
3.1.2 Luminance distribution
3.1.3 Illuminance
3.1.4 Glare
3.1.5 Obtrusive light
3.1.6 Directional lighting
3.1.7 Colour aspects
3.1.8 Flicker and stroboscopic effects
3.1.9 Maintenance factor (MF)
3.1.10 Energy considerations
3.1.11 Sustainability
3.1.12 Emergency lighting
3.2 Schedule of lighting requirements
3.2.1 Composition of Tables 3.5 to 3.19
3.2.2 Schedule of areas, tasks and activities
3.2.3 Lighting requirements for areas, tasks and activities
3.2.4 Lighting requirements for safety and security
3.3 Verification procedures
3.3.1 Illuminance
3.3.2 Glare rating
3.3.3 Colour Rendering Index
3.3.4 Obtrusive light

Chapter 4: Road lighting

4.1 Classification of roads
4.1.1 Traffic routes
4.1.2 Subsidiary roads
4.1.3 Conflict areas
4.2 Lighting classes
4.2.1 ME classes
4.2.2 S classes
4.2.3 CE classes
4.2.4 G classes

Chapter 5: Daylight

5.1 Daylight and health
5.1.1 Regulation of the circadian system
5.1.2 Mood
5.1.3 Seasonal affective disorder (SAD)
5.1.4 Ultraviolet (UV) radiation
5.2 Windows and view
5.2.1 Analysis of view
5.2.2 Size and proportion of windows
5.3 Daylight and room brightness
5.3.1 Sunlight
5.3.2 Skylight
5.3.3 Contrast between the interior and the view outside
5.4 Daylight for task lighting
5.4.1 Glare
5.4.2 Specular reflection
5.5 Electric lighting used in conjunction with daylight
5.5.1 Balance of daylight and electric light
5.5.2 Modelling
5.5.3 Contrast between exterior and interior
5.5.4 Colour appearance of lamps
5.5.5 Changes of lighting at dusk
5.6 Sunlight shading

Chapter 6: Energy

6.1 Simple guidance for energy efficient lighting
6.1.1 The right amount of light
6.1.2 Light in the right place
6.1.3 Light at the right time
6.1.4 The right lighting equipment
6.2 Energy regulations and standards
6.2.1 Building regulations
6.2.2 Dwellings
6.2.3 Non-domestic buildings
6.2.4 BS EN 15193
6.2.5 Schemes to support energy efficient lighting

Chapter 7: Construction (Design and Management) Regulations

7.1 Introduction
7.2 General management duties
7.2.1 Duties of clients
7.2.2 Duties of designers
7.2.3 Duties of contractors
7.3 Additional duties if the project is notifiable
7.3.1 Additional duties of the client
7.3.2 Additional duties of designers
7.3.3 Additional duties of contractors
7.3.4 Duties of the CDM co-ordinator
7.3.5 Duties of the principal contractor
7.4 Duties relating to health and safety on construction sites
7.4.1 Electricity distribution
7.4.2 Emergency routes and exits
7.4.3 Lighting

Chapter 8: Basic energy and light

8.1 Properties of electromagnetic waves
8.2 Evaluating energy as light

Chapter 9: Luminous flux, intensity, illuminance, luminance and their interrelationships

9.1 Definitions of the units
9.1.1 Flux
9.1.2 Intensity
9.1.3 Illuminance
9.1.4 Luminance
9.2 Interrelationships between the units
9.2.1 Flux and intensity
9.2.2 Intensity and illuminance

Chapter 10: Direct lighting

10.1 Illuminance from point sources
10.1.1 Planar illuminance
10.1.2 Cylindrical illuminance
10.1.3 Semi-cylindrical illuminance
10.1.4 Spherical illuminance
10.1.5 Hemispherical illuminance
10.2 Non-point sources
10.2.1 Line source calculations
10.2.2 Area sources
10.2.3 Recursive source subdivision

Chapter 11: Indirect lighting

11.1 Introduction
11.2 Sumpner’s method
11.2.1 Checking the results of lighting calculation software
11.3 Transfer factors
11.3.1 Basis of calculation
11.3.2 Calculation of form factors
11.3.3 The three surface case
11.3.4 The four surface case
11.3.5 Derivation of transfer factors

Chapter 12: Photometric datasheets

12.1 Photometric measurement
12.1.1 The C-γ system
12.1.2 The B-β system
12.1.3 Relationships between the two angular co-ordinate systems
12.1.4 Photometric centre
12.2 Elements of a datasheet
12.2.1 Normalised intensity table
12.2.2 Intensity diagram
12.2.3 Light output ratios
12.2.4 Spacing to height ratio (SHR)
12.2.5 Utilisation factor (UF) tables
12.2.6 Shielding angle
12.2.7 Normalised luminance table
12.2.8 Unified glare rating (UGR) table
12.2.9 Luminaire maintenance factor (LMF)
12.2.10 Spacing tables (emergency lighting)
12.3 Calculations for datasheets
12.3.1 Flux calculations
12.3.2 Calculation of spacing to height ratio
12.3.3 Calculation of utilisation factors
12.3.4 Calculation of normalised luminance tables
12.3.5 Calculation of UGR tables

Chapter 13: Indoor lighting calculations

13.1 Introduction
13.2 The illumination vector
13.3 Cubic illuminance
13.4 Derived values

Chapter: 14 Outdoor lighting calculations

14.1 Calculation of intensity towards a point
14.1.1 Calculation of C and c
14.1.2 Finding the intensity value I
14.2 The reflective properties of road surfaces
14.3 Calculation of illuminance and luminance
14.4 Calculation of glare
14.5 Calculations in other outdoor areas

Chapter 15: Measurement of lighting installations and interpreting the results

15.1 Light measuring equipment
15.1.1 Illuminance meters
15.1.2 Luminance meters
15.2 Field measurements
15.2.1 Operating conditions
15.2.2 Grids and illuminance measurement
15.2.3 Averages and uniformities
15.2.4 Measurement of road luminance
15.2.5 Other measures of spatial illuminance

Chapter 16: Colour

16.1 Introduction
16.2 Colour properties of light sources
16.2.1 Colour appearance in the CIE chromaticity (1931) diagram
16.2.2 CIE UCS (1976) diagram
16.2.3 Colour temperature
16.2.4 Colour rendering
16.2.5 Colour rendering index (CRI)
16.2.6 Colour quality scale (CQS)
16.3 Colour properties of surfaces
16.3.1 Munsell system
16.3.2 Natural Colour System (NCS)
16.3.3 DIN system
16.3.4 BS 5252
16.3.5 RAL design system
16.3.6 CIE L*a*b*

Chapter 17: Daylight calculations

17.1 Average daylight factor
17.2 Calculation of the sun position

Chapter 18: Predicting maintenance factor

18.1 Determination of maintenance factor
18.1.1 Indoor lighting
18.1.2 Outdoor lighting
18.2 Lamp lumen maintenance factor and survival factor
18.3 Luminaire maintenance factor (LMF) – indoor
18.4 Luminaire maintenance factor (LMF) – outdoor
18.5 Room surface maintenance factor (RSMF)
18.6 Ingress protection (IP) classes

Chapter 19: Glossary

Chapter 20: Bibliography

20.1 Standards
20.2 Guidance
20.3 References


CORRECTIONS (to be incorporated in text in due course)

June 2012:  On page 90, Table 3.2:
a) Column 4, 'Upward light', in row 3, delete '%' and
b) in list of definitions following table: for 'URL', delete ', and given in %'