GN01/20: Preventing obtrusive light – Put that light out! The issues around artificial light at night and at times by day are many and varied. This webinar looks at the various effects and concerns over artificial lighting installations. It will discuss and inform regarding the guidance, standards and regulations that are in place for planners, environmental officers, designers and installers to follow and consider to ensure everyone is managing all obtrusive lighting effects and concerns. This event is a precursor to the launch of the ILP online training course ‘Preventing obtrusive light – Put that light out!’ and follows on from the previous GN01/20 launch webinar in July of this year. The course will be available from the ILP training platform soon, with discounts for ILP members. By speaker: Allan Howard, BEng(Hons) CEng FILP FSLL, Technical Director for Lighting at WSP

1. ILP course launch event – LDC Ireland
9 December 2020
Preventing obtrusive light
Put that light out!

2. What is it about?
• So what is covered within the course?
– Artificial light at night
• Predominately from external lighting installations
• Relevant internal lighting installations
– Artificial light during the day
• Media signage
– Effects
• Predominantly the effects on humans
• Sky glow
• Not forgetting fauna and flora

3. Who is it for
• Anyone interested in or responsible for the effects of artificial light
at night
– Planners
– Environmental officers
– Lighting designers
– Legal representatives
– Environmentalists
– Astronomers
– ……..
Mike Hawtin, North York Moors National Park

4. Course content
• An online course
Session 1
1A What is obtrusive light?
1B What guidance and requirements exist?
1C Understanding & managing light spill
Session 2
2A Understanding & managing glare & sky glow
2B Illuminated advertisements & media
2C Evidencing the design & obtrusive light measurement

5. General mitigation
• Right light, in the right place, at the right time, controlled by the
right system
• Apply the five principles for responsible lighting:
– Useful, all artificial lighting should have a clear purpose
– Targeted, light should only be directed where needed
– Low lighting levels, light should be no brighter than necessary
– Controlled, light should be used only when it is useful
– Colour, use the right light source for the task

6. What is obtrusive light?
• Many forms

7. Definitions & terms
• Look to the definitions
– Light spill (light Trespass)
– Intensity
– Brightness
– Glare
– .....

8. What guidance and requirements exist?
• Published Regulations, standards and guidance for most lighting
tasks, adherence to which will help mitigate obtrusive lighting
aspects
• The Clean Neighbourhoods and Environment Act (CNEA) 2005
• National planning policy framework (NPPF)
• National planning policy
• Commission Internationale De L’Eclairage (CIE)
• Professional industry guidance

9. National planning policy framework (NPPF)
• Makes little reference to lighting with regard to the control of
obtrusive light
– Limit the impact of light pollution from artificial light on local amenity,
intrinsically dark landscapes and nature conservation
– The national on-line planning guidance resource
i. When is light pollution relevant to planning?
ii. What factors should be considered when assessing whether a development proposal
might have implications for light pollution?
iii. What factors are relevant when considering where light shines?
iv. What factors are relevant when considering when light shines?
v. What factors are relevant when considering how much the light shines?
vi. What factors are relevant when considering possible ecological impact?
vii. What other information is available that could inform approaches to lighting and help
reduce light pollution?

10. Professional industry guidance
• CIE (International Commission of Illumination)
– CIE 150; 2017 Guide on the Limitation of the Effects of Obtrusive Light
from Outdoor Lighting Installations; and
– CIE 126: 1997 Guidelines for Minimizing Sky Glow
• ILP
– GN01/20 Guidance notes for the reduction of obtrusive light
• Limiting performance laid down based upon environment zones

11. Establishing the base line
• Establish the environmental zone
• Establish the base line (on site survey)

12. Understanding & managing light spill
• Defined in terms of illuminance (Lux)
– Light falling on a surface
• Vertical i.e. windows of a premises
• Horizontal i.e. into a garden

13. Limitations on premises
• Potential for causing a nuisance
• Vertical illuminance
– Limits apply to existing or potential nearby dwellings, premises
– Specifically windows
– Values are the summation of all light sources

14. Note
• For example an E4 zone
– Limitation 25 lux
– Existing base line established at 10 lux
Does not mean you can add 15 lux

15. Installation
• Luminaire with the right optical distribution at the right mounting
height is critical to minimising light spill and obtrusive light effects
yet providing the right lighting performance on the task area

16. Fauna and flora
• Presence of bats and other protected
species
– Generally affected by blue light content
• Look to warm white light sources
• Amber light sources
– Different species affected in different
ways
– One size does not fit all
Bats and lighting E Stone 2014

17. Managing glare and sky glow
• The uncomfortable brightness of a light source when viewed
against a darker background
– A potential nuisance
• The brightening of the night sky

18. Glare
• Condition of vision in which there is discomfort or a reduction in
the ability to see details or objects, caused by an unsuitable
distribution or range of luminance, or by extreme contrasts
– Two main types of glare
• Discomfort glare
– Glare that causes discomfort without necessarily impairing the vision of objects
• Disability glare
– Glare that impairs the vision of objects without necessarily causing discomfort

19. Sky glow
• The brightening of the night sky
– Natural sky glow
– Artificial sky glow
– A phenomenon / climate dependent

20. Media screens
• Purpose
– To convey images / messages related to advertising, media and
information primarily to a surface located observer
• Concern
– The lighting distribution is such that they contribute to:
• Obtrusive light / Light nuisance
• Spill light
• Sky glow
– Type of display

21. Illuminated adverts, media & domestic lighting
• Institution of Lighting Professionals (ILP) PLG05
– Developed to address concerns over the brightness of advertising and
related static and dynamic signage, media screens & facades and
projected signage

22. Domestic lighting
• Well designed, installed and maintained domestic exterior lighting
brings comfort and wellbeing to our lives, providing us with a
sense of security and pleasure in our homes
• Potential for:
– Source of legal nuisance
– Adverse effect on safety of adjacent areas
– Obtrusive light / light pollution

23. Evidencing the proposal
• So what evidence should be requested / provided?
– Not just contour lines
• Core aspects
– Base line assessment survey results
– What is the lit task requirements?
• Appropriate software
• Include all input data
– Luminaire details, maintenance factors, mounting heights, tilt, aiming
angles ….
• Good range of appropriate horizontal and vertical iso-contour plots
– 0.5 lux upwards, not just the minimum but a full range of levels
covering the who area
• Intensity calculations

24. Competency of assessment
• The lighting requirements of any proposed installation should be
assessed by someone who is competent.
• A qualified lighting professional should form part of the planning
assessment team.
• Appropriate qualifications may include Membership of the
Institution of Lighting Professionals or the Society of Lighting and
Lighting.
– Many Authorities have a street lighting officer, or there are
consultants: the Institution of Lighting Engineers can provide a list.

25. Measurement
• Guidance on the measurement of obtrusive light from outdoor
installations is given within CIE 150
• ILP GN 3/16 Measurement of the photometric performance of LED
lighting installations

26. Problems design vs installation
• Contractor substitution
– Contractor drastically changes the design
– Contractor procures alternative products to reduce costs
– Lack of performance verification
• Competency of contractor
– Luminaires installed incorrectly, lack of understanding of
luminaire performance and installation configuration

27. Thank you
• Questions
This course contains tables from CIE 150:2017 and CIE 126:1997 provided for use in GN01
The copyright of the data detailed within these tables belongs to CIE, email ciecb@cie.co.at and the table used in this course document should be used in conjunction with CIE 150:2017 and CIE 126:1997 and not as a replacement for the
procedures contained therein.
These documents can be obtained from http://cie.co.at/publications and members of a National Committee of the CIE can purchase them with a discount of 66.7 %.