Guidance

Artificial light at night (ALAN) significantly impacts wildlife. Wildlife-friendly lighting design aims to minimise this impact while still meeting essential lighting needs (e.g., for safety). Refer to guidance from Bat Conservation Trust (BCT) and Institute of Lighting Professionals (ILP).

Avoid Unnecessary Light: Question if lighting is needed at all. Minimise duration (timers, motion sensors) and intensity.

Intensity & Brightness: Use lowest intensity necessary for the task. Avoid over-lighting. Measure illuminance (lux) at ground level/target area.

Light Spectrum / Colour Temperature: Use warm light sources (< 3000 Kelvin, ideally < 2700K). Avoid blue-rich white LEDs, as these have greater ecological impact (especially on bats/insects). Filters can sometimes be used on existing lamps.

Directionality & Shielding: Use directional fittings that only light the target area. Use full cut-off luminaires or shields/baffles to prevent upward light spill and minimise horizontal glare/spill onto sensitive habitats (e.g., hedgerows, water bodies, trees, known bat routes/roosts).

Controls: Use timers to switch lights off during less busy periods (e.g., post-midnight) or when not needed. Use motion sensors (PIRs) with short activation times where appropriate (e.g., security lighting, pathways), ensuring they don't trigger unnecessarily.

Location: Avoid installing lights near known sensitive habitats or features (bat roosts, badger setts, ponds, mature trees, dense vegetation). Maintain dark corridors for wildlife movement.

Design & Assessment: Integrate lighting design early in development process. Consider potential impacts on wildlife identified during ecological surveys. Specialist ecological/lighting assessment may be needed for sensitive sites.