Building

Most of us are familiar with air, water, and land pollution, but did you know that light can also be a pollutant? Here are some examples of light pollution:

• Glare: a visual sensation caused by excessive and uncontrolled brightness
• Light trespass: light falling where it is not intended or needed
• Sky glow: upward-directed light emanating from poorly designed or directed lamps and security floodlights

The architectural lighting on the house on the left was installed in a way that trespasses on the neighbouring property.

The house on the right has lighting on the lower floor only, directed down so as to not impact the neighbouring property.

Using shielded outdoor light fixtures that have a solid cap above the light bulb helps to prevent light from being emitted directly to the sky, minimizing sky pollution. The image below shows cap options with the most responsible exterior home lighting choice being on the far right.

• Illuminate only where necessary for safety and security purposes, such as doorways, paths, gathering areas, and staircases.
• Mount lights at a height no greater than is necessary. Consider eliminating soffit lighting from second floor eaves.
• Install motion sensors on outdoor fixtures so they turn on when needed and turn off after a short time. Make sure to adjust the motion detector sensitivity as needed to prevent lights from turning on and off unnecessarily.
• Install and aim lighting so it does not shine across property lines.
• Select full cut off or shielded fixtures that shine light downwards rather than sideways or upwards. Outdoor lights need to be within a fixture that aims light downward.
• Switch to LED lighting to reduce illuminance without compromising visibility. Select warm coloured LED bulbs with dimmers.