The Society of Light and Lighting (part of Chartered Institute of Building Services Engineers) has published new guidance that places much greater emphasis on creating a good visual environment for office workers. It is a laudable aim, but it could increase costs as it will require more input from designers. This may explain why developers and engineers seem reluctant to relinquish the old guidance and embrace the new.
When the original guidance was written in 1988, the technological equivalent of the Dark Ages, computers had highly reflective monitors, running programs with pale text on a black background. If the light source was reflected in the screen, workers could barely see the text. Lighting Guide 3 (LG3) was written specifically to address this problem.
The solution was to use luminaires that threw light directly downwards and cut the light off sharply at the edges so the source would not be reflected in the computer screen. There were three categories, defined by the cut-off angle: 55°, 65° or 75°, which could be used for different applications, depending on the work space.
But despite bathing work surfaces in light, the luminaires had the unintended effect of creating a gloomy environment. Their sharp cut-off angles left ceilings and upper walls in darkness, and the lighting itself was flat and featureless. The knock-on effect was that occupiers found their workplaces depressing, and productivity suffered.
Mark Major, principal of lighting designer Spiers and Major, concurs: "The old guidance was contributing to psychological problems in the workplace because of the bad lighting."
But the simplicity of the category system made it easy to design compliant lighting schemes – and the guidance could be used by anyone, including contractors and facilities managers. If clients complained that schemes looked boring, the designer could silence the moans by saying it complied with health and safety legislation. Category two – luminaires with a cut-off angle of 65° – was almost always chosen because, according to Meyrick, "it was in the middle". Manufacturers responded by churning out mountains of cheap and cheerful category two lighting gear, and it became the standard.
Meanwhile, computer technology moved on. Monitors now have anti-reflective treatments, and modern flat screens reflect virtually no light. Most software uses dark text on white so any reflections are barely noticeable.
So in January, the Society of Light and Lighting withdrew the category system and replaced it with a seven-page addendum. This places greater emphasis on creating a good visual environment, requiring 50% of the average light level on work surfaces to fall on walls and 30% on ceilings.
Lighting designers are in favour of the new guidance because it is likely to generate more work for them. Meyrick says: "In the past, lighting wasn't an issue; the new code is pulling lighting back into the conversation." Major also welcomes the new LG3: "I am very pleased it has changed, having spent 10 years saying why it should be."
Electrical contractors, though, are less likely to be pleased. Robert Thorogood, director of service engineering at architect Aukett Europe, thinks the increased design input required by the guidance means contractors will no longer be able to design schemes. "It will be more difficult for them; I imagine they will have to employ a consultant," he says. This could add costs and cause delays to lighting installations and – as the new guidelines are not yet compulsory – could prove a barrier to their widespread adoption.
Some developers are cautious about the new guidance because they fear litigation on health and safety grounds. But the revised LG3 takes account of health and safety concerns and Meyrick points out that, to his knowledge, nobody has ever been sued over bad lighting.
It seems likely that the real sticking point for developers will be additional costs. "Speculative office developers are the problem," says Jonathan David, secretary of the Society of Light and Lighting. "They want a hard number they can put in their specification. You can't put a number on quality." As a result, he thinks it will take at least five years for the guidance to have any impact.
Another factor slowing the wholesale adoption of the revised guidelines is the attitude of the British Council for Offices. Publications editor Timothy Battle is revising the BCO's fit-out guide in response to the new LG3. He says: "If it's not mandatory, developers won't do it. They have to be pushed." But the BCO is not, as yet, prepared to pile on the pressure: Battle says the council will probably recommend that developers follow the new guidance only if they want to.
Energy use is a further concern. Major says the new guidelines advocate less efficient energy usage because "indirect lighting is inefficient". He fears people will use the same lighting intensities as before, but increase the number or size of the fittings to provide additional lighting on walls and ceilings. Hoare Lea's Meyrick believes there could be a similar problem where a category two fit-out is being updated, with designers simply supplementing it with wall and ceiling lighting. However, both Meyrick and Major point out that if a scheme is intelligently designed using the new guidance, with careful focusing of light on pertinent areas, it could actually lower energy consumption. And sophisticated developers will hopefully take the guidance on board when they see how it can add value to their schemes.
Fit-out contractors will probably end up complying with the new code in any case, as quick-off-the-mark manufacturers are busily producing fittings that are being flagged as new LG3-compliant. These include pendant fittings designed to throw light up on to ceilings as well as down on to work surfaces.
Even where low ceiling heights demand recessed fittings, complying with the revised guidance will not be impossible thanks to new fittings that protrude slightly to project light on to the surrounding ceiling area. It is probably only a matter of time before special fittings are available that project the prescribed amount of light high up on to walls, yet also cut off the light at the correct angle in the main space.
The new LG3 may be bringing lighting into the 21st century, but that does not mean it will necessarily promote good design. "I don't think that guidelines in general promote good design, because they tend to get treated like law. Clients will simply ask 'does it comply with the new LG3 to the letter?'" says Major. "Nothing replaces a well-qualified lighting designer or engineer responding intelligently to the brief."