Lighting guides
Working progress Simon Robinson discusses the key changes and considerations in the newly updated Lighting Guide 7 on office lighting For many of those who work in an office environment, their workspace is more than just somewhere to carry out a task. The space has to try and meet a number of requirements. It has to be safe, comfortable, visually stimulating, efficient and productive. Lighting plays a large part in trying to achieve those goals and some of the demands on the lighting installation have changed considerably in the past 10 years. The current version of LG7 was released in 2005 and the intervening 10 years has seen a significant change in the technology we use as well as how many of us use our office space. While the move to technology such as smartphones and tablets has changed our understanding of how to provide a suitable lighting installation, the ever-increasing need to reduce energy has added to the challenges for the lighting designer and installer. Lighting design is an integral part of a holistic approach to providing spaces that people want to occupy and it is more
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important than ever for designers and building owners to discuss how the lighting design should be developed. The 2015 revision of LG7 seeks to address these issues as well as provide guidance on associated and emerging technologies within the built environment. Key areas of revision and newly introduced guidance include: A new chapter on the approach to design A greater emphasis on energy use and how to get the best
out of lighting designs while being mindful of the need to reduce energy A revision to guidance on how to approach speculative offices Guidance on how to deal with the ‘hot desk’ approach to office use A new chapter discussing the interaction with mechanical systems and their effect on lamp colour and efficiency Guidance for new and refurbishment projects How to approach cylindrical illuminance and the application of modelling ratios A new chapter on how to deal with tablets and touchscreen use in offices A new chapter which gives some practical examples of how lighting could be considered for an office space The chapter on the approach to design gives a basic overview of the issues to be considered when designing a lighting installation for an office. It can be used for quick reference on a number of topics and is supplemented by more detailed later chapters. Lighting in offices accounts for around a quarter of total energy use within a building and as we move closer to the day when buildings will be carbon neutral as a matter of course, lighting designers will need to consider energy use and how to be creative while maximising the benefits for the amount of energy used. With this in mind, the guide now considers energy use more prominently. Localised lighting solutions are favoured where possible as this gives a good opportunity to reduce energy use by concentrating the highest illumination level on the task area, allowing it to be decoupled from the general lighting. This can also allow the lighting designer more freedom when designing circulation space lighting. Speculative office accommodation usually refers to a space which is being developed for a future tenant or owner and so there is unlikely to be any desk layout to consider when providing a lighting design. Providing a general lighting design to cover all eventualities can be wasteful of both energy and resources, particularly if the lighting is significantly changed once an owner or tenant takes up residence. LG7 encourages lighting designers to consider these aspects in discussion with the developer or building owner. Fluorescent lamps have become particularly sensitive to temperature and the guide now discusses the impact that overcooled lamps can have on colour temperature and efficiency. Fluorescent lamps are likely to be with us for some years to come and the relationship between artificially cooled spaces, air flow patterns and fluorescent luminaires needs to be carefully considered. Perhaps the biggest single change in how we use offices is the introduction of touchscreen displays, tablet computers and smartphones. Rather than being tied to a specific desk, people increasingly work where they feel comfortable and with screens in any orientation, so designing lighting to minimise reflections is now becoming much more difficult. LG7 now addresses this problem and makes suggestions about the appropriate