Guidance Note 01: For the Reduction of Obtrusive Light
Institute of Lighting Professionals: Guidance Note 01/2021
The Institute of Lighting Professionals (ILP) is a UK based professional organisation which publishes a series of Lighting Guides, aimed at educating lighting designers and non-specialists in lighting related matters.
Guidance Note 1, often referred to simply as GN01, deals with the subject of ‘obtrusive light’, also known as light pollution and light trespass. For planning purposes, this includes the protection of Dark Skies, local communities and neighbouring properties. Much of the guidance is derived from international standards published by the International Commission on Illumination (CIE). The benefit of GN01 is that it places the CIE standards in the context of UK planning policy, standards and law.
A key concept in GN01 is the ‘Environmental Zone’ classification, ranging from intrinsically dark rural landscapes to brightly lit urban centres, classified from E0 to E4, respectively. When you have determined the zone in which your development is located, you can then use this document to find out what the limits are for obtrusive light. For planning applications, GN01 is often used by Local Planning Authorities to assess lighting proposals.
