Light Pollution – LEEDing concerns

Light Pollution from Space

Can you pick out the various continents in the images above? The difference between the night skies visible in the country versus within the city was our early clue of the excessive night-light being generated by urban environments. You could actually see the glow of the city on the horizon from the countryside. The greatest realization came with space travel when we could see the dramatic effects of light pollution in our urban environments from outer space.

Sustainability and LEED certification address this growing issue of light pollution and focus on means to reduce the negative effects of lighting at night. Our thoughts typically go to the idea of outdoor lighting and how to control it better. And, this is indeed where the majority of the night light pollution occurs.

LEED addresses light pollution in the category of Sustainable Sites Credit C8; Light Pollution Reduction. This credit is worth one point towards certification. While there are a number of credits that are only one point; we need to get each one that we can and this one should be easy to achieve. The concept of reducing light pollution is to have the light pointed towards the ground instead of horizontally or even worse upwards.

The concept goes further than reducing the effects of lighting the sky and seeks to limit light spillage which is light leaving the limits of your property. Have you known anyone that has had to deal with a neighbor’s back yard flood light that stays on all night and shines directly into their bedroom? Perhaps you have a personal experience of this sort. This effect is also referred to as light trespass.

Urban Light Pollution

Perhaps the greatest purpose of night lighting is for human safety. But being mindful of light trespass and excessive lighting levels beyond levels needed for safety is something we need to work towards. The FSB design had achieved proper levels of lighting on the site without spillage, however, as we analyzed achieving this credit, we realized that the design of the building itself was now contributing to light pollution.

How was this possible? It was our high bay gallery space with the extensive areas of glass that provided great views of the adjacent parkland during the day. Turns out at night, those same extensive areas of glass allowed the indoor lighting to spill outside of the building.

Light Pollution from within

The solution:

“Reduce the input power (by automatic device) of all nonemergency interior luminaries with a direct line of sight to any openings in the envelope by at least 50% between 11pm and 5am.”

Easily done by the incorporation of automatic light controls that would achieve the LEED objective stated above. The only catch, this is not currently addressed in our documents and we will need to work with the construction team to get it incorporated.

Coming ahead:

  • Masonry Veneer Construction
  • Curtain Wall Installation
  • Recycling Construction Waste
  • Closing Out the Project

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