Dark City: A holistic approach to urban lighting
We need to illuminate our cities. Our urban centres virtually grind to a halt when the lights go out.
The presence of artificial light not only allows us to extend the day, supporting our basic need for safety and security, but also provides the means by which key social and economic activity takes place after dark.
Good lighting can greatly improve life within any city or town. It empowers us to venture out into the dark, helping to create social cohesion and encouraging us to share space, and promote activity. In the UK alone the night-time economy is valued at over £66bn.
But illuminating our cities and towns comes with a price: Lighting accounts for more than 19% of global energy production: light pollution doesn’t simply block our view of the stars but can adversely influence our sleep patterns while also having a serious impact on local bio-diversity.
The illumination of our cities and towns is not just street lighting, but is made up of complex layers of both private and public light in various ownerships:
- The base layer – the internal light through the glazing of our offices, shops and homes.
- The increasingly private-owned lighting to highways, roads, paths, squares, subways and all manner of routes and spaces.
- The applied illumination of buildings, landscapes, signs, media screens, retail lighting, security lighting – the list goes on.
All of these make up the lighting of the city - often combining with no reference to each other at all, leading to over illumination.
So how can we better control the use of artificial light?
1. Plan the lighting of our cities on a more holistic basis
We plan our urban environment in great detail and within carefully defined legal frameworks for many things from aesthetic to environmental control.
Lighting, however, is still not sufficiently considered. Although many developments are now subject to providing lighting strategies, the lack of knowledge about artificial light within the planning authorities remains a problem.
The implications of planning decisions on lighting are not always properly considered - both in terms of night-time character and potential environmental impact. Moves must be made to address this - and urgently.
2. Change our attitudes towards the amount of light we use and its control
While we are not nocturnal creatures, we have evolved to see in extremes of light. This ranges from dim moonlight (less than 1 lux) to bright sunlight (in excess of 100,000 lux).
Despite this we continuously seek to use larger and larger quantities of light than are needed, rather than properly considering the light quality and effect – which are key to determining the legibility of our visual environment.
Contrast and adaptation become the main problem. The more light that is used in one area the darker the adjacencies become. This results in a dialling up of lighting levels as we attempt to resolve issues such as fear of crime.
That is not to ignore the important role that lighting plays in making urban areas safe and secure. But the answer cannot be to brightly light up every square metre of public space.
Rather we need to understand more about the complex relationship between light and human behaviour – and begin to realise that less can be more.
3. Improve general education about light and lighting
Despite our growing appreciation of the value of good lighting we are still remarkably ignorant about the technologies that produce it.
It could be argued that much of our thinking about artificial light and its benefits has been directed by those who supply and manufacture lighting products.
And although there are undoubted energy savings to be made by employing exciting new technologies, their hidden environmental impact has not been fully enough considered – especially in terms of whole life cost to the earth.
For example the disposal of highly toxic low energy lamps such as compact fluorescent can cause issues with landfill. Also, low energy technologies do not necessarily make us use less light – media facades only became a possibility with the advent of LEDs.
While we would not, and should not aim to turn the clock back to pre-electric civilisation, we must take stock and evaluate how far we have come since Edison first introduced us to relatively affordable light at the flick of a switch.
The time has arrived when we should begin to see electric light as a highly precious resource that must be properly planned and controlled to meet the requirements of the community as well as the individual.
The only way forward is to improve general education – to learn to use this commodity more sparingly but also to great effect. Only then can we begin to create truly sustainable lighting development.
Mark Major is a Principal of Speirs + Major and a Royal Designer for Industry.
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