When designing outdoor lighting requirements, there is a factor that doesn’t seem to get talked about much, lighting zones. These zones are used to help determine how much light is required for a specific area. These are broken up into 5 different zones:
LZ0: No ambient lighting
Areas where the natural environment will be seriously and adversely affected by lighting, such as parks, preserves or undeveloped rural areas, are in LZ0 – lighting zone 0. Lighting in these areas impact the biological cycles of flora and fauna and can even distract from human enjoyment. What little light is required in the residential areas near these locations should be extinguished when not needed.
LZ1: Low ambient lighting
Areas where lighting might adversely affect flora and fauna or disturb the character of the area, such as residential single or two family areas, agricultural zones, rural residential zones, business parks and open spaces in developed areas, are in LZ1 – lighting zone 1. In these areas, lower light levels are used for safety and security but are not always uniform or continuous. These lights can be extinguished or reduced when activity levels decline.
LZ2: Moderate ambient lighting
Areas of human activity where the vision of human residents and users is adapted to moderate light levels, such as neighborhood businesses, churches, schools, neighborhood recreation or areas with modest nighttime uses, are in LZ2 – lighting zone 2. In these areas, lighting is used for safety and security, but again is not always uniform or continuous. After curfew, these lights can also be extinguished or reduced when activity levels decline.
LZ3: Moderately high ambient lighting
Areas of human activity where the vision of human residents and users is adapted to moderately high light levels, such as business districts, commercial areas or industrial and manufacturing zones, are in LZ3 – lighting zone 3. In these areas, lighting is used for safety / security and convenience and is typically uniform and / or continuous. After curfew, these lights can also be extinguished or reduced when activity levels decline.
LZ4: High ambient lighting
Areas of human activity where the vision of human residents and users is adapted to high light levels, such as high density entertainment districts or heavy industrial areas, are in LZ4 – lighting zone 4. In these areas, lighting is considered necessary for safety, security and/or convenience and it is mostly uniform and/or continuous. After curfew, lighting may be extinguished or reduced in some areas as activity levels decline. This is not used as a default zone.
Understanding which zone your project fits within will ensure your lighting design is correct. Talk to your lighting designer to establish what lighting zone fits your project application best if you are unsure. This will help determine the lighting level and spacing requirements that fit best.