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  • Writer's picturePeter

'BS 5489-1:2020 - What's Changed?'

Updated: Aug 6, 2021

Earlier this year the British Standards for street lighting were updated. This is a short post to look through this latest edition of the British Standards for road lighting, the BS 5489-1:2020 and what's changed from the previous version published 7 years ago.

Why the update?

Due to the predominant use of white light throughout the road lighting industry the standards needed to reflect this shift away from the SON and SOX light sources.

  1. SP ratios discontinued when using white light. SP ratio is now applied if using an orange light source.

  2. To ensure alignment with the EN 13201 which was updated in 2015. Two years after the last published BS 5489:2013.

  3. To align with the latest CDM Regulations update in 2015.

  4. Incorporating smart cities.

Significant Changes

Absolute or relative photometry - the BS states that lighting design can be carried out using absolute or relative photometry and that both have advantages and disadvantages, and there is no preferred option as either method is expected to produce the same result.

Ecology - a section on ecology has been provided. It references the GN08/18 Bats and Artificial Lighting in the UK and notes that designers should liaise with ecologists.

Glare and TI% - threshold increment should be used for both P and ME classes as a way of considering the glare, instead of the luminous intensity classes. For are calculations i.e. conflict areas it is difficult to do this as a calculation and the luminous intensity class should be relied upon.

P Classes now have a prescribed maximum TI% - see below table:

Threshold Increment (Max Values for P Classes)
Maximum fTI values for P classes

Sustainability - a section on sustainability has been provided. This section provides guidance on how to achieve a sustainable lighting solution. The economic, environmental and social sustainability of the installation should be considered through the lifecycle stages of the project. The following lifecycle stages are presented:

  • Policy

  • Design

  • Installation and Commissioning

  • Operation

  • Maintenance

  • Decommissioning and Disposal

This was just a quick look at the significant changes within the revised standard. Overall, we're pleased with the amendments. In particular, we're happy to see some focus on ecology and sustainability.

If you need a project lit to the latest British Standards for street lighting, get in touch here.

All the best,



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