Dark Sky and Lighting, Just a Buzzword or Something We Should Take Seriously?

You may have heard people talking about dark skies and wondered whether it is simply another phrase that has become fashionable in design and planning. It is a fair question. After all, we need light to help us use and enjoy places after dark.

But dark skies are about much more than being able to see the stars. They are about recognising that darkness has value, and that the lighting we choose can affect people, wildlife and the character of a place.

What do we mean by dark sky lighting?

Dark sky lighting does not mean leaving every street, garden or entrance unlit. It means thinking carefully about whether light is needed, where it should fall, how bright it should be and when it should be on.

Imagine a path beside a hedgerow. People may need enough light to find their way safely. The hedgerow, however, may be an important route for bats. A thoughtful scheme would consider both, lighting the route for its intended use while avoiding unnecessary spill into the habitat. In some circumstances, the best decision may be to leave part of the site dark.

That is a design question, not simply a matter of choosing a fitting labelled “dark sky friendly”.

How a light is aimed, installed and controlled matters as much as the fitting itself.

Why does it matter?

For wildlife. Night-time is part of the natural environment. Artificial light can affect how some species move, feed and use their habitats. Bats are a particularly important consideration on many projects, but the question is wider than bats alone. The effect depends on the species and the location, as well as the light’s intensity, direction, colour and operating hours.

For people and places. Light spilling into a bedroom window, glare from a poorly aimed fitting or a bright wash across a previously dark landscape can change how a place feels at night. Good lighting should help people use a space without creating avoidable disturbance beyond it.

For the night sky

Light sent upwards or reflected unnecessarily contributes to sky glow. Even when each individual installation seems small, the combined effect can make the night sky harder to appreciate.

For energy use

Lighting an area that does not need to be lit, or leaving lights on long after they are needed, uses energy without adding value.

Do planners and lighting professionals take it seriously?

Yes. Government planning guidance in England specifically addresses light pollution, including effects on dark landscapes, neighbouring properties and wildlife. It asks decision-makers to consider where, when and how much light is used.

The Institution of Lighting Professionals also publishes technical guidance on obtrusive light. Its 2026 guidance is titled The Avoidance of Obtrusive Light, reflecting the value of addressing unwanted light early in a design. Separate guidance developed with the Bat Conservation Trust addresses bats and artificial lighting at night.

The detail required will vary from project to project. A garden, a housing development and a public space will not all need the same solution. What matters is understanding the site before deciding where the lights go.

What can thoughtful lighting look like?

It might mean:

* lighting the area people actually need to use, rather than flooding the whole site;

* selecting and positioning fittings to control glare and spill;

* preserving genuinely dark areas and wildlife corridors where appropriate;

* setting suitable light levels for the task and surroundings; and

* using dimming, timers or other controls so light is available when it is needed.

None of these is a universal rule that can be applied without looking at the site. A safe, usable and attractive space can still be sensitive to its surroundings. The work lies in finding that balance.

A subject worth exploring

Dark skies are something we care deeply about at Circalume. Over this series, we will look at what light pollution really means, how lighting can affect wildlife, why planning teams ask for lighting information, and how better design can protect the night-time environment. Because the most useful question is not simply, “Can we light it?” It is, “What needs light, and what deserves to remain dark?”

If you are planning external lighting for a development, garden or public space, Circalume can help you develop a strategy that responds to the people using the space and the environment around it.