Scottish Government

INTRODUCTION

BACKGROUND TO GUIDANCE NOTE

1. This Guidance Note has been prepared to support the Partnership Agreement ¹ commitment to reduce light pollution and save energy by specifying appropriate lighting standards. This Guidance Note is also referenced to in the Lighting Environmental Protection Regimes Annex of The Scottish Executive's Planning Advice Note 51: Planning Environmental Protection and Regulation. ² There are no specific legislative controls on light pollution, but the Scottish Executive are considering adding artificial light pollution to the list of Statutory Nuisances under Part III of the Environmental Protection Act in 2007 when a suitable legislative vehicle becomes available. This has been done for England and Wales, commencing April 2006.

COLLABORATIVE WORKING BETWEEN ORGANISATIONS

2. Environmental Protection Regimes operate alongside the land use planning system which aims to ensure that development takes place in suitable locations and is sustainable, while also providing protection from inappropriate development. Planning Advice Note 51 summarises the statutory responsibilities of the environmental protection bodies, as well as informing these bodies about the planning system. To minimise any overlap or duplication of controls it is essential that planning authorities and the protection agencies understand each other's role and work together so that the controls are applied in a complementary way. This is important because many environmental protection decisions are based on quantitative standards whereas planning decisions have to take into account a much wider range of material considerations and the weight to be accorded them. It has been documented in the Institution of Lighting Engineer's 2006 Annual Conference that close working between planners and local authority lighting engineers is having an impact in reducing the amount of light pollution. It is recommended that collaborative working takes place between the relevant local and central government organisations responsible for lighting, planning and environmental issues.

OBTRUSIVE LIGHT AND ENERGY EFFICIENCY

3. -Light in itself is not a pollutant and in the context of this document the term Obtrusive Light has been used throughout. Obtrusive lighting installations have a negative impact on the appearance of the night-time environment and can lead to complaints about the quality of their installation. In recent years there have been concerted campaigns, led mainly by the Campaign for Dark Skies to reduce the level of Light Pollution that can be seen above all our major cities. The application of the recommendations in this Guidance Note, along with the use of modern lighting units can help reduce this light obtrusion into our night skies.

4. -Poor lighting designs can result in a waste of valuable energy which is at odds with the Scottish Executive's climate change policy ³ of reducing the country's overall energy usage. It is therefore essential that lighting installations are both efficient in their application and in their use of energy. This Guidance Note is intended to encourage developers, architects and lighting designers to consistently provide non obtrusive and energy efficient lighting designs.

5. -Well designed lighting installations can provide very positive benefits to communities through the reduction in the perceived risk of crime, the enhancement of general public safety and generally adds to the feeling of well-being of a community through the positive message that well maintained lit areas provide. However the converse is equally true and care should be taken in the design of new and refurbished lighting installations to maximise the aforementioned benefits from good design practice.

6. -Obtrusive Lighting is presently not classed as a Statutory Nuisance in Scotland, although in England and Wales it now can be. There are plans however to add light pollution to the statutory nuisance regime in Scotland in the near future, which should be taken into account when considering the guidance on Applicable Lighting Situations referred to in paragraph 7.

APPLICABLE LIGHTING SITUATIONS

7. -This Guidance Note relates to all exterior lighting situations no matter the size or location of the lighting project or whether it is a stand alone project or part of an overall development. Potential developments and lighting situations include but are not limited to:

PURPOSE OF GUIDANCE NOTE

8. -This Guidance Note provides guidance on the factors that require to be considered and the actions to be undertaken to ensure that non obtrusive and energy efficient exterior lighting installations are provided and operated throughout Scotland.

9. -The Guidance Note is not intended to provide detailed guidance relating to the design, installation or operation of any particular lighting situation, but to provide general guidance that should be followed by developers, architects, lighting designers and those involved in the design, delivery and operation of lighting infrastructures whether as stand-alone projects or as part of an overall development. Recommendations are also included for local authorities with respect to developing a lighting policy and inclusion of self certified documents recommended in this Guidance Note with the consent management process.

10. -This document is not intended to cover the problems associated with poorly installed domestic security lighting which is covered as part of a document published by the Department for Environment, Food and Rural Affairs. ⁴

APPLICATION OF GUIDANCE NOTE

11. -Developers, architects, lighting designers and lighting installation contractors should apply the guidance provided within this document. It is essential that developers, architects and lighting designers ensure that the lighting design process, operational statement and installation records to record compliance are prepared for provision to each local authority in accordance with their relevant consent management process. Local authorities staff have a central coordinating role in having this Guidance Note adopted as part of the overall design process.

WHAT IS OBTRUSIVE LIGHT?

12. -There are five effects associated with obtrusive light and these are as described in paragraphs 13 through to 17.

13. Sky Glow, can occur in two different forms:

Sky Luminance	Site Aura

-Sky Luminance occurs when direct upward light reacts with and is diffused through clouds, mists, and airborne particles that exist in the atmosphere. The area and brightness of the resultant sky luminance is entirely dependent upon the presence and quantity of these various diffusing elements and the level of upward light being distributed from the luminaire.

-Site Aura occurs in the same way as sky luminance but is related to those lighting effects caused by indirect light reflection local to the lighting installation and is normally restricted to a dome of light issued upwards from the locality of the surface being illuminated.

Light Presence
Glare	Intrusion

14. Light Presence

-Where light emitted from a light source or that projected on to an area or building, can be viewed from outside the area it was provided for, and causes minimal visual discomfort but fails to reach an intrusive level, then this is termed "light presence". This light presence may draw attention to the existence of a lighting installation, or structure that was previously inconspicuous by day.

15. Glare

-This is perhaps the most serious form of obtrusive light and can cause a general visual discomfort, which can seriously impair vision with poorly designed lighting installations. The impact of glare is dependent upon the quantities and directional nature of the glare source, the physiological status and age of the person affected, the general nature of the area in which the glare effects occur, and the surrounding levels of ambient lighting.

16. Intrusion

-Light trespassing into an area beyond the intended illuminated subject areas, such as into adjacent residential properties. Light intrusion may be the result of a single source or multiple light sources acting together, none of which need be a source of glare. The same measured value of light intrusion is likely to be less of a problem in a well lit urban area than in a previously unlit rural situation.

17. Flicker

-The periodic, often deliberate, flickering of light used for advertising and attraction-seeking purposes can prove to be distracting and like glare, promote degrees of irritation, annoyance and distress. The rate of flicker and the duration of exposure can cause over-stimulation of electrical activity to the human brain. Over exposure to and excessive stimulation by flicker and similar lighting such as strobe lighting has been known to induce attacks in people who suffer with epilepsy or migraine.

BASIC LIGHTING ENERGY PRINCIPLES

18. -The unit into which the lamp is fitted is called a luminaire and all luminaires are required to comply with the relevant European standards. However, in terms of light distribution there can be a wide variance in the light distribution characteristics of differing luminaires and this is an important factor in delivering the required lighting performance and subsequently its energy efficiency: All luminaires used in any lighting scheme should be of a consistent type throughout.

19. -In general, the closer the light appearance is to white light then the greater is the energy required to provide the same light output (lumen). However, the whiter the light the greater the visual recognition, and this can result in lower quantities of light being necessary to provide the same task illumination.

20. -Although not directly associated with this Guidance Note it is important that health and safety matters are considered for all installations, particular the maintainability of the lighting installation.