Workplace Lighting: The Office Environment – featured in EE Publishers’ Vector Magazine

This article is featured in the February 2015 Edition of EE Publishers’ Vector Magazine –

The lighting in the majority of South African offices is neither particularly innovative nor particularly energy efficient. All too often the only lighting designed for our offices is either fluorescent of one type or another with the entire office area lit to a single light level.

A new United Kingdom Business Council for Offices guide

The guide was published on 26 September 2013. According to my overseas colleagues, it was difficult to produce because of the lack of both alignment between all of the different standards and research about office lighting. The publication was timely given the ever-more onerous energy requirements for commercial spaces, recently published standards such as BS EN 12464 and changes in technology.  We believe that we are going to see LEDs hitting the office-lighting market extensively over the next 12 months.

We also have considerable lack of alignment between the various SANS documents and the current OHS standards.  Despite my frequent discussions with the Department of Labour which is responsible for the Occupational Health and Safety on this subject regarding the revision of the requirements particularly in respect of the light levels required and their response stating that the revision progressing, almost three years later, there is no visible and tangible evidence of any progress.  

The time has come for all those who are active in the lighting design workspace to practice what I was taught in 1976/1977 by Thorn EMI Lighting and at University.  I am sure that those of my vintage were similarly taught, to design lighting appropriately and imaginatively for offices.  Of course at that time we had to make use of what was available such as incandescent lamps, HPS uplighters and the typical fluorescent luminaires of the day.  We did not have the exciting LED technology at our disposal.

The UK BCO guide simply re-directs all lighting professionals, architects and engineers back to those sound lighting design practices which were taught so many years ago.

The Principle of Effective Lighting for the task 

It is possible for architects, designers and engineers “to create better quality spaces, but also save energy at the same time.”  Our lighting design for the office refurbishment of Caxton Publications, Craighall, Johannesburg is a prime example of our Blair Hammond & Associates trademark approach to lighting design.  It provides the users with interesting, efficient and compliant lighting whilst at the same time being very energy efficient at 5.03 W/m².

This was achieved by using a model which was taught 37 years ago.  The concept principle is as follows:

  1. The Primary Work Plane : The direct task area to be lit to the appropriate light level.
  2. The Secondary Area : The light level for the area surrounding the direct task area to enable the occupant to transfer from the direct task area to for example file storage, computer peripherals, etc, should be one third lower than the Primary work plane light level.
  3. Transient Areas : The light level for those areas used for movement around the office and for socialising should be between 50% and 66% lower than the secondary level but not less than 100 lux.



The task area may vary between 0.5 m² to 1 m² and should be lit to the appropriate light level for the particular task which may be between 300 lux and 500 lux.  Typically a drawing office (where actual architectural drawing is done) should be lit to about 500 lux, whilst most other offices where typical office routine prevails and which requires the use of computers should be lit to a maximum of 300 lux.

I am fully aware of the fact that at this time, it is in conflict with OHS.  For example, OHS requires the work plane to be lit to 500 lux where any computer task is carried out.  This is outdated particularly when opticians and other health specialists state that the radiation emitted from brightly lit computer screens is detrimental to our eyes.  They logically recommend that the brightness control on the screen should be turned down to a comfortable level.  In order to be able to view the screen images effectively then, the light level on the work plane MUST be lower.  The resultant light level directly addresses the visual well-being of the worker which indirectly addresses the overall well-being, comfort and thus the potential productivity of that person.  A level of 500 lux as is prescribed by OHS is excessive, will cause discomfort glare and where older type CRT (Cathode Ray Tube) monitors are in use, disability glare could result from excessive reflections on the screen.  Furthermore, continuous use of monitors on high brightness reduces the life expectancy of the monitor and leads to premature decrease in brightness potential.

When the lighting professional embraces these principles, they will find that they will be able to design far more interesting and appropriate light solutions.  Colour variations appropriate to the various areas can be introduced.  Colour variation is excellent for those working in the office.  Each time that they look at the different light levels and colours, their eyes are exercised which also in effect reduces light stress and eye fatigue.  Furthermore, when they return to their Primary work plane, the contrast will stimulate higher levels of productivity.

LED lighting provides the lighting professional with amazing variety of products which afford them flexibility in terms of beam angles and colours.  LED lighting can be effectively combined with conventional lighting systems when required.  Most importantly, LED lighting is excellent when combined with lighting control technologies to optimise the longevity and energy efficiency qualities of LED lighting.  LED lighting has brought almost boundless opportunity and excitement to lighting design added to this is the fact that LED lighting is still evolving at an amazing pace.

How to Approach the New Office Development

It is much simpler to design the lighting for existing office which is being refurbished or for a new office development where the occupants or tenants have already designed the office layout.  This was addressed in the preceding section above.

The new office development requires an entirely different approach.

The developer or landlord should be advised to provide basic lighting for the Transient area and to make an allowance for a lighting design and luminaires for the Primary and Secondary areas after a tenant or occupant has been finalised and after they have provided their specific workstation and office general layout.  This approach will firstly avoid reverting to the inefficient type of lighting design both in terms of lighting and energy consumption with overall light levels in excess of the levels which will actually be required for the various areas as defined above.  Furthermore, this approach provides the developer or landlord with the opportunity to make a value proposition to potential occupants or tenants.


This brief overview is by no means intended to be for instructional purposes, but rather to serve as an “eye-opener” to all of those who are passionate about lighting and to take us all back to the basics.  It is also intended to make the office lighting and thus the workplace more interesting and a better place to spend the many hours at work.

I am always reminded of the three pillars of good environmental stewardship – People, Planet and Profit.  By providing a working place which is designed for the well-being of the people who work there in the most energy efficient way, productivity will be high and profit potential will automatically be possible and enhanced.

Vector Magazine Link –



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