Member questions: PIR lighting control and sensor location for connected buildingsJanuary 2017

Jayne Sunley, Information Manager

Written by Jayne Sunley, Information Manager, BSRIA

Q. I am currently working on a project with a lighting control system which is controlled by PIRs. Standard office floors have lights energised by PIRs so when we enter the floors we have no switches. The consultant for the project has stated that to comply with Building Regulations a light switch has to be within 6 m of any desk space or twice the ceiling height, whichever is greater. Can you clarify if this is correct please?

The legal requirement in Part L of the Building Regulations states that “Reasonable provision shall be made for the conservation of fuel and power in buildings by… providing fixed building services which… have efficient controls.” It does not specify a requirement for PIRs to have controls in a specific location.

The only specific guidance comes from BRE Digest 498 Selecting lighting controls which is a third tier guidance document for the Building Regulations. The 2014 edition of BRE Digest 498 gives guidance on occupancy-controlled lighting, but does not mention anything about retaining light switches. However, it does specify that if manual controls are used the switch should be within 6 m of the luminaire it controls, or twice the height of the luminaire above floor level, whichever is greater.


Q. We’ve been tasked with installing new emergency lighting in an office building. Would you know what the life expectancy is for self-contained lighting?

According to CIBSE Guide M (updated in 2014) the economic life expectancy of both self-contained and externally powered emergency lighting is 25 years. However, BS 5266-1:2016 Emergency lighting - Part 1: Code of practice for the emergency lighting of premises gives recommendations and guidance on the factors that need to be taken into account in the design, installation and wiring of electrical emergency lighting systems.


Q. Are there any specific requirements or recommendations for deciding on the location of sensors for connected/automated building systems?

When looking at connected buildings systems IET published a guide in 2016 Code of Practice for Connected Systems Integration in Buildings that aims to offer a reference on the practices and technological considerations of such systems. In the guide they suggest three vital considerations for the location of sensors which should:

  • Minimise the risk of accidental damage
  • Allow for easy access for battery replacement or wiring positions
  • Allow for sufficient protection from malicious damage or interference.


Q. When designing a building that is to house an archive collection what approach should we take in terms of mitigating the effects of pollutants?

PAS 198:2012 Specification for managing environmental conditions for cultural collections has a whole chapter on pollution that might be able to help answer your question. The standard does suggest an ‘evaluate-monitor-mitigate’ approach and offers advice on low-cost assessment methods for monitoring common pollutant levels.

The publications mentioned in the questions above are all available to borrow by BSRIA Members from the BSRIA library, open 8.30 - 5.00pm Monday to Thursday, and 8.30 - 4.30pm on Fridays.
E: information@bsria.co.uk T: +44 (0) 1344 465571

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