Tranquillity and Light pollution

Policy POSP7: Tranquillity in the Broads

  1. Outside settlements, development proposals will only be permitted where they conserve and/or enhance tranquillity.
  2. All development proposals will need to protect the dark skies and nocturnal character of the Broads in accordance with the dark skies policy PODM27.

Reasoned Justification

The tranquillity of the countryside and historic sites should be valued and protected.

Tranquillity is subjective and relative: whether a place feels tranquil will be different for everyone, however there are common characteristics which help us refine our understanding. Tranquillity can be understood as being made up of a variety of sounds and experiences which help people find peace and a sense of wellbeing within the landscape. Most commonly these factors include:

  • Feeling close to nature and wildlife
  • Feeling solitude and remoteness
  • Hearing natural sounds
  • Seeing unspoilt natural beauty

Tranquillity is a quality of calm that people experience in places full of sights and sounds of nature, and National Parks and the Broads are viewed as one of the best places to gain this experience. Tranquillity can be damaged by the intrusive sights and sounds of man-made structures such as new roads, poorly designed lighting and power lines. New developments may create additional noise, particularly in the context of road traffic, industrial equipment and recreational activities, as well as during the construction phase, and should be considered when taking decisions on new development proposals. In addition to the above, the setting of heritage assets (designated and non-designated) can make an important contribution to their significance. The setting of a heritage asset is defined as the surroundings in which a heritage asset is experienced, and tranquillity, remoteness and wildness can be important attributes affecting how a heritage asset is experienced. In order to protect the tranquillity of historic sites the contribution of tranquillity on the significance of heritage assets should be considered

Of relevance to tranquillity are these policies:

  • Dark skies/light pollution policy PODM27.
  • Amenity policy PODM26.
  • Settlement fringe policy PODM25.

Indeed, there are some particular areas around the Broads which are generally tranquil such as the Upper Thurne (Policy POSSUT) and the Trinity Broads (Policy POSSTRI).

Reasonable alternative options

No policy

Sustainability appraisal summary

The following is a summary of the assessment of the policy and alternative(s).

A: Have a policy: 5 positives. 0 negatives. 0 ? Overall, positive.

B: No policy: 0 positives. 0 negatives. 5 ?

Why has the alternative option been discounted?

There are areas that are tranquil in the Broads. Tranquillity is one of the special qualities of the Broads. A general, strategic policy that seeks to protect tranquillity is favoured.

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Policy PODM27: Light pollution, dark skies and nocturnal character

See Policy map at Appendix 15.

  1. The tranquillity, nocturnal character and dark sky experience of the Broads will be conserved and enhanced.

Dark sky zones of the Broads

  1. Development proposals are required to address light spillage and eliminate all unnecessary forms of artificial outdoor lighting by ensuring that:
    1. Dark Sky Zone category 1 as identified on the policies maps is protected from permanent illumination;
    2. External lighting within the Dark Sky Zone category 2 as identified on the policies maps is strictly controlled; and
    3. Good lighting management and design is applied throughout the Broads.

Development proposals involving lighting

  1. Development proposals will be required to identify sources of light and indicate how the scheme will look in the dark as part of any application. Proposals shall be accompanied by a lighting strategy, with detailed specification of any proposed lighting units and demonstrating how consideration has been given to maintaining intrinsically dark skies.
  2. The impact of introducing light to an area which previously had no lighting, regardless of how well designed the lighting it, will be a key consideration.
  3. Development proposals that involve external lighting, outside the Dark Sky Zones category 1, will only be permitted where it can be demonstrated that they are required for a specific, identified and justified lighting task – see later in policy for requirements relating to design.

Design of lighting

  1. If lighting is proven to be required, in line with the rest of this policy, development proposals must demonstrate that all opportunities to reduce light pollution (including sky glow, glare and light spillage) have been taken, including minimising impacts on local amenity, intrinsically dark landscapes and areas important for nature conservation and nature recovery.
  2. Artificial lighting proposals (including outdoor lighting, floodlighting and new street lighting) will be minimised in terms of intensity and number of fittings.
  3. The applicant must demonstrate that:
    1. the minimum amount of lighting necessary to achieve its purpose is specified; and
    2. the design and specification of the lighting would minimise sky glow, glare, and light spillage in relation to the visibility of the night sky, local amenity and local character; and
    3. the means of lighting would be unobtrusively sited and well-screened by landscaping; and
    4. low energy lighting is used; and
    5. there would not be an adverse impact on wildlife.
  4. All lighting units provided must be downward facing and shielded to prevent upward emission of light; be no brighter than the minimum required for the lighting task and be fitted with PIR sensors.
  5. All ground-based lighting units to mark pedestrian paths and similar areas, shall be located no higher than 1 metre above ground level and all wall mounted lighting units shall be located as low as practicable and shielded to prevent upward emission of light.
  6. All lights need to be off when not needed and dimmed down when little human activity.
  7. Applicants are required to demonstrate that proposals meet or exceed the Institution of Lighting Professionals guidance and other relevant standards or guidance for lighting[93].

Light spill from internal lighting

  1. Building design that results in increased light spill from internal lighting (through glazed facades, roof lights or windows) needs to be avoided, unless suitable mitigation measures are implemented.
  2. Any proposals and designs that include roof lights, lantern lights, and/or floor to eaves and floor to gable glazing, will not be supported unless, as appropriate to the design of the building, integral blinds, or louvres or external ‘brise soleil[94]’ fixed louvres, are provided as mitigation.
  3. All such blinds and/or louvered units that are not easily accessible, must be provided with automatically operated, light sensor systems, to ensure closure at dusk.

Reasoned Justification

The natural environment and people’s health and quality of life will be protected from unacceptable levels of light pollution. No or low levels of light pollution are an important aspect of tranquillity.

Light pollution/obtrusive light comes in many forms:

Obtrusive light can take several forms:

  • Sky Glow: the brightening of the night sky. Sky glow is a product of light being scattered by water droplets or particles in the air.
  • Glare: the uncomfortable brightness of a light source when viewed against a darker background. Glare is created by light that shines horizontally.
  • Light Spill: the spilling of light beyond the boundary of the area being lit.
  • Light Intrusion: the presence of light from sources outside the affected person’s property. Intrusive light occurs when unwanted artificial light illuminates an area that would otherwise be dark.
  • Over illumination refers to the use of artificial light beyond what is required for a specific activity.
  • Light Presence: sources of light in otherwise dark views.

These are all forms of obtrusive light, which may cause nuisance to others, or adversely affect fauna and flora as well as waste money and energy.

There is firm evidence of issues arising because of artificial lighting. Wildlife and human health can be affected and inefficient use of lighting wastes money and energy, affecting homes and businesses.

Artificial lighting is not detrimental in all cases, and the solution to light pollution is not necessarily turning off all lighting. Light pollution refers to artificial light that is excessive or intrudes where it is not wanted or expected. For example, some older street lights emit light pollution, as do security lights mounted at an angle above the horizontal. Well-designed lighting, on the other hand, sends light only where it is needed without scattering it elsewhere - “The right amount of light and only when and where needed” (Campaign for Dark Skies motto).

The NPPF says that Local Plans ‘should limit the impact of light pollution from artificial light on local amenity, intrinsically dark landscapes and nature conservation’.

The Authority has assessed the Broads Authority Executive Area and results show that most of the area has good quality dark skies, with most readings being over 20 magnitudes per arc second. While the Authority’s survey looked upwards, the CPRE[95] undertook a study that looked down to the earth. Both datasets were assessed and compared and have informed the final zones as set out in the policies map. A report explaining the assessment between the two datasets has been produced. Recently, we checked a sample of some of the survey points – see this Topic Paper. The Authority therefore considers that the Broads is an intrinsically dark landscape which must be preserved.

Dark Sky Zone Category 1 is the darkest area within the Broads Authority Executive Area reaching over 21 magnitudes per arc second. In this zone, permanent illumination is not allowed to protect the darkness of the sky. On occasions, there may be a need to have external lighting for short periods of time, but the design of this lighting is expected to not add to light pollution when used and not expected to be lit for long periods of time. The design of any lighting is expected to meet tests that follow.

Dark Sky Zone Category 2 is the second darkest area within the Broads reaching over 20 magnitudes per arc second, but less than 21. These skies are still intrinsically dark and as stated in the NPPF the impact from artificial light needs to be limited. As such, the design of any lighting is expected to not add to light pollution and meet the tests that follow.

The current International Dark-Sky Association criteria consist of Five Principles for Responsible Outdoor Lighting, and this implicitly includes indoor lighting that illuminates the outside. These are:

  1. All light should have a clear purpose. This purpose should be identified before a light is installed or replaced. Consider the impact of the light on wildlife and the environment and consider the use of reflective or luminous markers for signs, curbs, and steps.
  2. All light should be targeted. Use shielding and careful orientation so that light does not spill beyond where it is needed.
  3. Light should be no brighter than necessary. Use the lowest light level required and consider whether the lit surfaces will reflect light into the sky. Use dimmers if different light levels are needed.
  4. Light should be used only when it is useful. Use timers and motion detectors (e.g. PIRs) to ensure that light is available when it is needed and is turned off at other times. Lights should turn off a maximum of 5 minutes after motion ceases.
  5. Use the warmest colour with the lowest Correlated Colour Temperature [CCT] possible. In practice, this means that external lighting should have a maximum CCT of 2700K (2200K preferred) unless there is an identified requirement for a higher CCT.

Essentially there are two ways of avoiding light pollution in new developments. Firstly, at the design stage, features that have the capacity to contribute to light pollution are either not included or ‘designed out’ of the scheme at an early stage or are effectively mitigated. Secondly, any required lighting follows the ‘right light, right place, right time’ philosophy. The key message therefore is that ‘designing out’ is avoiding the problem, which is the preferable solution, whilst the provision of blinds or louvres is ’mitigation’.

When considering lighting as part of a scheme, applicants need to consider the following early in the design of a scheme, with an assessment and plan showing lighting proposed and how it will look at night, submitted with the planning application:

  • Which zone are you located in?
  • Do you need light in the first place, and if so, why?
  • What is the lighting task/area to be lit?
  • Are you over lighting? What is the minimum lighting you require?
  • If lighting is required, is it designed to not add to sky glow and minimise glare and not result in intrusive light, and not over illuminate? How?
  • How will you ensure the lighting only be on/activated when it is needed?
  • For windows, rooflights and glazed facades, what mitigation will be included in the scheme?

Windows need effective curtains or blinds, and internal light units that are lower than the top of windows need to be appropriately shaded. Those ‘windows’ that are angled upwards, such as roof lights and lantern lights, either need to be designed out of the structures or to have integral blinds or louvres that can be closed at night to prevent light pollution. In some situations, extensive floor to ceiling or floor to gable glazing, which can be common in some modern dwelling designs, may be proposed. Whilst passive energy gain can be beneficial, extensive areas of floor to ceiling glazing also clearly have the capacity to emit a considerable amount of light at night above the horizontal, which is not acceptable. Therefore, for buildings on the edge of villages or in relatively isolated locations, large areas of extensive glazing can detract significantly, and arguably disproportionately, from the objectives of mitigating the negative impacts of artificial light at night. In addition, when lantern and roof lights are proposed in relatively inaccessible positions, this makes the manual operation of blinds or louvres impracticable. In these situations, the blinds or louvres should be automatically operated by light sensitive switches, to close at dusk.

In terms of the information required as part of planning applications, the Authority requires illustrated and written description of the detailed Lighting Concept for all external lighting including street and amenity lighting, illuminated signage and media, building and landscape lighting and the illumination of art and internal lighting. For larger scale developments, it will be necessary for planning authorities to require that a lighting strategy and a specification is included within applications, to demonstrate that schemes, would be Dark-Sky compliant, once implemented.

Lighting schemes on their own do not always need planning permission. If the Authority seeks and is awarded Dark Sky Status, work will be undertaken in key areas to reduce the impact of light pollution, in partnership with the local community.

Important guides

Reasonable alternative options

Original policy

No policy

Sustainability appraisal summary

The following is a summary of the assessment of the policy and alternative(s).

A: Original: 7 positives. 0 negatives. 0 ? Overall, positive.

B: No policy: 0 positives. 0 negatives. 7 ?

C: Preferred Policy: 7 positives. 0 negatives. 0 ? Overall, positive.

How has the existing policy been used since adoption in May 2019?

According to recent Annual Monitoring Reports, the policy has been used and applications have been determined in accordance with the policy.

Why has the alternative option been discounted?

The Broads has intrinsically dark skies. The dark skies are part of the character of the Broads. Given the area of the Broads, with many urban areas nearby, it is important to have a policy that protects the dark skies of the Broads. The amendments provide clarity and further considerations relating to if lighting is required.

  • [93] For the purposes of the ILP lighting guidance (CIE 150:2003 Guide on the Limitation of the Effects of Obtrusive Light from Outdoor Lighting Installations ) the Broads Authority is included within Environment Zone 1 as a reflection of its protected status and its intrinsically dark skies.

  • [94] Brise soleil is a type of solar shading system that uses a series of horizontal or vertical blades to control the amount of sunlight and solar heat that enters a building. The name 'brise soleil' comes from the French word 'sun breaker'.

  • [95] Night Blight: Night Blight 2016: Mapping England's Light Pollution and Dark Skies - CPRE