As a Lighting Consultant, I help clients improve their installations by determining how to control light which spills beyond and above the boundaries of their facilities.
Outdoor Lighting
Guidance for the control of obtrusive lighting has existed since 1990 and was updated in 2013. These guidelines define the limits of light spilt upward and outward into premises or passing into living rooms or bedrooms. Yet, it is not stated how to achieve the desired results.
Light emitted directly upwards causes skyglow and can be considered as waste and reduces our ability to see the stars in the night sky and for optical observatories to obtain clear images of the planets above us. In addition, the many particles in our atmosphere, including those emitted by human activity, such as carbon emissions from our built environment, including power stations, homes, and commercial facilities, also reduce our ability to see the stars in the night sky.
In my view, there is no reason not to provide zero direct upward light and work towards lighting systems with the lowest reasonable energy demand. What we need to consider is what the system looks like when viewed from outside the facility in terms of apparent brightness intensity and how disturbing or dangerous this may be to passers-by, residents, or road users.
Planning Consent
Local authority regulations always include requirements for limiting stray light when planning a new lighting installation. Stray light through a living room or bedroom window can, over time, impact human health by providing too much light at the wrong time, contributing to disturbed sleep-wake cycles, which impacts our circadian system and in turn, can impact our health if exposure is present over a significant amount of time.
I always ensure to work with local authority ecologists to determine whether wildlife or sensitive habitats need to be considered, which informs and shapes the design process.
Climate Change
The impact of the warming climate leading to ever more extreme weather events caused partly by increasing emissions is becoming ever more prevalent. Governments are committing to carbon reduction targets to limit global warming to no more than 1.5 degrees Celsius based on the Paris agreement.
There is an increasing requirement to reduce carbon emissions. For lighting installations, this principally means connected load or power consumed at the point of use while meeting all other specified criteria.
For outdoor lighting installations, this is different from choosing the highest claimed lumens per watt or the energy category found on product packaging, which can be misleading. Because it does not look at how well a product performs as part of a specific project or application and how the specified criteria for the illumination of the sports surface or obtrusive light parameters are achieved.
The products used all come with embodied energy contained within the materials and components from which they are made. Environmental Product Declarations are starting to be used where a product is assigned, a ranking based on its level of sustainability, much like the energy labelling system, which has been in use for many years.
People living and working beyond the facility’s boundaries do not want to be disturbed by stray light for aesthetic and health reasons. The designer can mitigate or, at the very least, minimise these effects.
Each site is unique, and as part of developing a lighting scheme, the solution cannot be considered in isolation from the surrounding environment. Well-considered systems meet the most demanding criteria using well-conceived, controlled, and adjusted lighting systems.
To discuss with me further about this topic or any other lighting requirements, feel free to contact me on michael@michaelgormanlighting.com
Michael Gorman
Executive Director Michael Gorman Lighting