Guardians of the Night: Part 3
March 2025
At DW Windsor, we remain committed to responsible lighting practices. To further this commitment, we recently interviewed leading Dark Sky experts and consolidated their insights into a five-part series called Guardians of the Night. These articles illuminate the impact of light pollution and propose practical steps to mitigate it. Grounded in expert knowledge and research, these recommendations serve as a guiding framework for sustainable nighttime lighting solutions.
Part 3 - Key considerations for designing DarkSky Approved lighting schemes
The following article provides thought-provoking insights and practical guidance when designing Dark Sky approved lighting schemes that mutually benefits the end-user and our environment.
Establishing a baseline for responsible lighting
The starting point is to understand the baseline – what is the present condition, and what’s the impact caused by the existing scheme? This can be achieved by taking measurements on a clear night to check how the lighting is currently affecting the sky (Asfuroglu, 2024). The key is knowing how light is used, why it is needed, and what it achieves. It’s this joined-up thinking that matters (Bissell, 2024).
Furthermore, what do you need the lighting to do, what is its function, and does a certain area actually need lighting? We don’t always ask these questions, but we should, and this allows us to explore if we can invest in fewer lighting points while achieving a higher quality output (Bissell, 2024).
It is very important to be realistic about the environment. The right balance needs to be found between what is possible and the client’s need to meet certain standards. There is always an optimal point between what a client wants and what the environment needs, and there will always be reductions available across all elements to get the best solution (Asfuroglu, 2024).
It’s also important to consider what the site is for, who the client is, and why lighting is required within each space. It can often be a problem when designs or architectural plans prioritise lighting to create an aesthetic rather than focusing on practicality (Bissell, 2024).
By asking the right people the right questions, these challenges can be addressed. Awareness is improving, but we are learning all the time. We also must ensure the right person is fulfilling each task. This will allow us to ascertain whether lighting is needed in the first place and ensure that the best people are involved to achieve the optimum outcome (Bissell, 2024).
Integrating dark sky principles into lighting design
Designs should ensure that Dark Sky principles are embedded within the earliest stages of work and that lighting is not added as an afterthought. The reason for this is that although lighting designs can be compliant, there may be opportunities within the overall design that could eliminate the need for lighting. For example, the better design of conflict areas and the removal of obstacles that are difficult to perceive in the dark. However, this is challenging, as lighting designers need to be consulted at the earliest stages, and the industry tends to overlook this (Oakley, 2024).
The ROLAN principles play a crucial role for lighting designers and help to set out five responsible lighting principles. One is assessing environmental impact—working out whether we need light in certain places. Furthermore, it asks important questions, such as whether lighting should be turned off during migration seasons to limit the impact on wildlife (Yakushina, 2024).
Designs should also ensure that the presence of lighting is factored in. This element is often missed, as existing guidance tends to cover the impact of lighting upon installation and not the suitability of lighting in sensitive areas. This is a difficult issue to fix, as every design is different. However, provided that the designer follows the recommended EIA guidance, it should be considered within the design. It is then up to the local planning authority to decide (Oakley, 2024).
Designs should ensure that Dark Sky principles are embedded within the earliest stages of work and that lighting is not added as an afterthought. Although lighting designs can be compliant, there may be opportunities within the overall design that could eliminate the need for lighting altogether.
—Dan Oakley, Darkscape Consulting
Minimising light pollution while protecting wildlife
Other considerations that are a high priority when designing lighting solutions that honour wildlife and Dark Sky environments include precise light control. Opting for fixtures with tightly controlled vertical cutoff angles will keep light directed downward, reducing skyglow and disturbance to nocturnal animals. This is set out in the IDA information on Vertical Cutoff (Mazhar, 2024).
Research on Wildlife and Light has shown that choosing warm-coloured LEDs that emit less disruptive blue light will align with natural wildlife behaviours and minimise ecological impact. Adding to this, adaptive lighting can be used. This includes the installation of systems with programmable controls to adjust light levels seasonally. Dimming lighting during breeding or migration seasons will minimise disruption to wildlife activities. The IDA’s guidance on Seasonal Adjustments recognises this (Mazhar, 2024).
Also focusing on wildlife is the implementation of tailored habitat lighting, as identified in the Wildlife Conservation Society – Habitat Protection guidance. Designating zones with reduced lighting intensity in sensitive habitats like wetlands and forests preserves critical ecosystems while enhancing nighttime visibility (Mazhar, 2024).
For this, the IDA Vegetation Buffer Zones recommends integrating natural vegetation buffers between lights and wildlife areas to mitigate direct light spillage and provide additional habitats. This approach supports local wildlife populations. Adding to this, a focus on natural rhythms is important. Coordinating lighting schedules with natural cycles to maintain consistency for nocturnal species will minimise confusion and stress caused by artificial light, promoting healthier wildlife environments (Mazhar, 2024).
About the authors
Andrew is a past president of the Society of Light and Lighting and a Partner at Ridge and Partners LLP. He has worked in lighting design since 1996, currently leading Ridge’s lighting design team. During his presidency, Andrew developed guidance to protect the night sky, supported early-career professionals, and raised the profile of lighting specialists within the construction industry. His projects span various sectors, focusing on improved design processes, enhanced environments for both people and wildlife, and reduced energy use and material waste. More recently, Andrew has contributed to large-scale Dark Sky initiatives in the UK and Saudi Arabia.
Kerem is the founder of Dark Source, an award-winning lighting design studio in the UK and Ireland guided by environmental principles. After earning an MA in Architectural Lighting Design from Wismar University in 2010, he spent 7.5 years at Speirs Major before establishing Dark Source in 2019. Named a Dark Sky Defender by Dark Sky International, Kerem has led projects such as the Plas Y Brenin Outdoor Centre, Presteigne Dark Sky Community, Newport Dark Sky Masterplan, Cloughjordan Ecovillage, Clwydian Range & Dee Valley, and Dark Sky Planning Guidelines for Cumbria. His work highlights low-impact solutions that harmonise built environments with nature.
Yana is a lawyer, researcher, and dark sky protection educator currently pursuing a PhD at the University of Ghent under the Horizon EU PLAN-B project, where she also serves as one of the scientific coordinators. Yana specialises in light pollution regulations and space law, leading and contributing to international projects on the development of the protection of the nocturnal environment, and collaborating with various organisations, including the Space Court Foundation Inc., the EU Commission, DarkSky International, Starlight Foundation, the International Astronomical Union, and UNOOSA. In 2023, she co-founded the Belgian dark sky organisation Living Night (DarkSky Chapter).
Dan Oakley is a dark sky expert and founding director of Darkscape Consulting. He previously served as the Dark Sky Officer at the South Downs National Park Authority, overseeing the IDA International Dark Sky “Moore's” Reserve application and developing planning policies and technical guidance. Dan chairs the International Dark-Sky Association (IDA) Places Committee and is a founding member of IDA-UK. He also established and coordinates the UK Dark Skies Partnership to reduce light pollution. With degrees in physics, wildlife management, and environmental policy, Dan has earned multiple accolades, including the IDA Dark Sky Defender award.
Hiba is an award-winning Architectural Lighting Designer based in Dubai, contributing to innovative lighting solutions for international public, urban, and interior projects with a focus on sustainability and dark sky practices. Recognised for her pioneering work, Hiba's research titled "Reimagining Traditional City Lighting with New Light Recipes to Confiscate Light Pollution" was presented at SLL CIBSE 2022, earning her a finalist position in the CIBSE Research Competition. Her research also highlighted the effects of city lighting on animals. Hiba’s accolades include the SIGNIFY Global Lighting Design Awards 2021 and an “Honourable Mention” in the LIT Awards 2022. By merging technical expertise with creative vision, she is redefining architectural lighting, championing designs that safeguard ecosystems and enhance urban landscapes.
Steve is a Fellow of the Royal Astronomical Society who has authored numerous articles and books on practical astronomy. For over 40 years, he has taught astronomy to adults and children, sharing his passion through lectures, workshops, and hands-on sessions. He serves as the Dark Skies Advisor to both the Federation of Astronomical Societies and the International Dark Sky Reserve at Cranborne Chase National Landscape. In addition to speaking at astronomical societies in Britain and abroad, he regularly addresses Rotary, Probus, and U3A groups. Steve also writes a monthly column for BBC Sky at Night Magazine, reviewing equipment and literature.