The office environment has changed considerably since the previous version of this lighting guide. While the fixed desk remains a central part of office life, tablet and touchscreen computers are now commonplace and allow those occupying office space to move around, effectively carrying their workspace to wherever they need to be or feel comfortable working.The need to accommodate this flexibility has brought significant challenges to lighting designers used to dealing with fixed scenarios. This guide now considers how to light office space for flexible use where tablets, smartphones and touchscreen computers are being used.Energy reduction in the built environment is a continuing challenge and the lighting within offices is a major contributor to the energy demands of a building. Careful selection of luminaires and light sources along with appropriate controls can reduce energy demand. However, designers and installers can make a significant impact by talking to the people who will use the office at a very early stage of the design. By understanding their needs and work profiles, a more tailored approach can be considered which delivers the lighting they need using the minimum energy.Speculative office lighting, and to a degree lighting for any large office, is still thought of as needing to be uniform across the office space. The notion of a working plane has been removed from this guide, with emphasis placed instead on the task area. Uniformity across a task area is important. However, uniformity across a whole office can make the space look bland and uninteresting. Using lighting as part of the interior design to add visual interest will improve the views of occupiers of an office as they look up and away from their desks.While it is easy to think of office space as large open-plan areas in dedicated complexes, the majority of office space in the UK is actually in smaller premises, where the office is one room among many and, possibly, converted from some oth