Decorative street lighting is an area where Light/Space/Design is a leader in both education and design. As principal Donna Leban likes to say, decorative street lighting cannot be designed “by the numbers” or by daytime appearance alone. The difference between a comfortable outdoor lighted setting and one with obnoxious and sometimes dangerous glare from lighting is one of understanding light quality and the effect of night lighting on the human visual response.

Here are some “green” outdoor lighting issues to consider:

1. Levels of outdoor lighting that are higher than current IESNA (the Illuminating Engineering Society of North America) guidelines are generally not advisable. Not only does it waste energy, it can be visually disruptive to neighboring homes and businesses.
2. Contrast ratios between the brightest and lowest outdoor areas are more important than average footcandles in determining outdoor lighting visual quality. This includes lighting on adjacent properties. Most lighting ordinances do not reflect this basic quality parameter.
3. The color qualities of light have a direct impact on our nighttime vision. Whiter light, typical of metal halide or fluorescent systems, provides better visual response under low light levels. Therefore, yellow high pressure sodium lamps are no longer preferable for higher efficiency. However, HPS is still a good choice for long lamp life and reduced maintenance costs.
4. The same lamp wattage and type can appear quite different in one outdoor luminaire compared to another. Fixture design and construction is important, and as a rule, you get what you pay for. Fixtures should be selected for their performance as well as their appearance.
5. Area lighting with floodlights should be avoided in most ordinary situations, particularly in permanent installations where surrounding light levels are low. Controlled floodlighting can be appropriate in special uses such as sports events, airport tarmack, and for temporary outdoor events. Harsh glare from floodlights has been implicated as the cause of accidents in parking lots and roadways, where drivers are temporarily blinded by oncoming floodlight.
6. Hiring a qualified lighting consultant such as Light/Space/Design for outdoor lighting projects can save developers from costly battles with neighboring businesses and residential communities. A consultant who is familiar with the site and neighboring conditions will deliver a solution based on specific site conditions. This is usually not the case with a design prepared by a manufacturer in a distant city.
7. A custom development deserves custom design. Light/Space/Design works with landscape architects and architects to achieve a very special outdoor lighting aesthetic for the most discriminating clients.