Getting the light right

Visual quality can take place in several aspects and relates to the manner in which contrast reveals form is our physical response to the balance of light and dark. 

We all know that when moving from a bright to a dark area or vice versa, that our eyes need time to adjust - a process know as adaptation. We can see in very low levels of light, such as moonlight (approx 0.2lux) and in very high levels such as sunlight in a clear sky (approx 100,000 lux). We can respond quite comfortably to sudden, relatively small variations of intensity. What we can’t easily cope with, however, is major shifts in the quantity of light so that we experience either glare, or conversely temporary blindness due to the sudden and unexpected absence of sufficient illumination. Over-lighting is a common problem in the urban environment. 

By lighting up one area brightly an adjacent space gets darker by contrast. Spaces in a building need first to be viewed individually but then, as all these spaces make up one building, they need to be seen as a whole. 

Gone are the days were lighting design is all about sticking to the 500lux in a defined space height ratio of an office space and forgetting about its visual appearance, while its adjacent corridors which are probably left with only amenity lighting to merely be productive after the sun sets. Lighting design has progressed to include aesthetics as well as increased functionality. When viewing the same office space, the defined 500 lux are still a necessity but these are combined with good colour rendering, a welcoming atmosphere and an inviting space. Views to the outside world create a more relaxed working space, which is why I insist on the provision of natural daylight, as it can increase productivity and morale among employees. The same goes for residential lighting. Who does not long to return home at night in an inviting living room? 

Cost of lighting 

Yet as we don’t live in a world with an endless wealth of resources nothing comes without a cost and we have to be very responsible that what we design is sustainable and not detrimental to generations to come, therefore in all the lighting design projects energy efficiency is an incredibly important factor that has to be taken into account. Energy efficiency can occur in various ways, from the type of lamps used in a lighting scheme to dimming controls, controls of natural daylight, valuable working diagnostics of the amount of hours this scheme will be used every day. Any lighting scheme has both initial and running costs, where the running costs vary from the agreed maintenance schedule when replacing lamps to the consumption on a daily basis. 

Switches and dimming 

How often to we have an office space which is lit up with the same amount of light level all throughout the day! Most offices use a combination of natural and artificial light and a controlled dimming system is invaluable. For example the quantity of artificial light required at 11am on a sunny day in June in a sun even half that required at the same time in January on an overcast day. Controlled dimming is required as our eye’s adaptation process is very adjustable and we can get accustomed to over-lit or under-lit environments very easily. Therefore daylight programmed dimming helps us both have an environment with balanced lighting whilst also being cost effective. 

I believe that in the commercial and industrial industry consciousness on energy efficiency is what has been taken care of for quite some time now. So much so that manufacturers hardly ever promote their “energy effective” products in these areas as these sell themselves. The heated debates and endless advertising on ‘energy efficient’ products are now bombarding the household market. 

Investment in lighting depends very much on the end result. In a retail environment, the correct lighting may boost sales as it can affect the way in which skin tones are perceived, making women more likely to purchase a bikini for example if the right lighting is applied to dressing rooms. 

Natural daylight 

Daylight can be used indoors in various aspects. We should take advantage of the ample natural daylight and sunlight that we have available. If trading hours fall during daylight hours then making use of natural lighting should be of top priority, both from an environmental and a commercial point of view. Skylights offer a solution to darker rooms, though these will need blinds or shades during the peak summer months. An innovative system involves the use of fibre strands, which bring natural daylight into the building. This system works by having glass or acrylic fibre strands that are installed in the ceilings and redirect sunlight from the source, which may be just one wall, through the fibres and onto the ceiling, bathing the entire room in natural light. This scheme needs to be installed at the design stage of a building, however it is proving to be very efficient.