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STEM Lightning Assessment

What is a Lightning Assessment?

  • This decides if you can build houses, a school or anything else provided that the artificial light (ambience) levels are alright there.
  • Can also be used to assess effect on bats and pollination.
  • Artificial light can come from:
    • Street lighting.
    • Flood lighting for sports pitches/car parks.
    • Vehicle headlights along the roads.
    • Domestic and security flood lighting
  • The natural world and all its wildlife must not be disturbed!

What do you need to know?

  • Site survey to look at insects and wildlife that currently reside there.
  • Existing lighting levels (measured in Lux) in the hours of darkness.
  • Even the weather, specifically cloud cover affects lighting levels!
  • You need to plot the Lux readings on a diagram that shows patterns in the distribution and if development will exacerbate this.
  • Look at what standards you need to meet.


Standards have to be met.

  • Artificial light should not be emitted from premises so as to be prejudicial to health or nuisance.
  • The impact of light pollution from artificial light should be limited on local amenity, dark landscapes and nature conservation!
  • The Institute of Lighting (ILE) has published its own Ambience Scale of 0 (Dark) to 4 (Bright), getting progressively brighter with each step.
  • The ILE has identified pre- and post-curfew luminance levels for external lighting installations, based on daylight hours.

Ways of protecting light?

  • Limit the lamp post’s height to 8m and spacing them out can reduce spill of light into unwanted areas such as natural habitats.
  • Other ways to reduce light spill include the use of lanterns with louvres / shields that reduce glare. Flat lanterns without glass bowls are best.
  • Security lighting should use a lamp that is PIR sensor activated, to ensure the lights are only on when required and turned off when not in use.
  • If applicable the presence of bats on the site should be considered and lighting levels should be kept to a minimum in these areas.
  • Try looking for these on your way home if you are walking!


Lightning Assessment Summary

  • Can the site be developed without generating excessive lighting levels.
  • What needs to be done to reduce glare?
  • Will insects and wildlife still be able to live at the site?
  • Can you sleep at night come to think of it!
  • Any artificial lighting introduced must comply with all standards.


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