Why cities are calling time on their traditional bright lights
As more cities look to cut excessive artificial light, adapting building lighting can make a big difference
The days of brightly illuminated urban skylines could be numbered as more cities clamp down on excessive artificial light.
London’s Square Mile is the latest urban area to propose plans to reduce visual pollution and save energy by requiring owners to switch off unnecessary lights within certain hours.
In the U.S., New York’s Dark Skies Act will require most non-essential outdoor lights to be turned off, covered or switched to sensor activation after 11pm to reduce the numbers of migratory birds who become fatally distracted. Pittsburgh, meanwhile, is moving to lower-wattage, blue-minimizing LED bulbs and adding streetlamp shading to dial down the effects of light on homes and habitats, following other designated International Dark Sky Places such as Flagstaff, Arizona and Fulda, Germany.
“Lighting design historically prioritized visual comfort and occupant safety over its impact on the external environment,” says Patrick Staunton, Sustainability Associate at JLL. “Now, an increasing focus on ecology, alongside a greater understanding of the impact of artificial lighting on people and biodiversity, means that tackling light pollution is becoming a critical part of urban sustainability strategies.”
It ties in with wider calls for more sustainable energy usage across real estate. Earth Hour, on March 26, asks people across the world to turn off their lights for an hour to raise awareness about energy consumption and its impact on climate change.
“Light pollution represents significant amounts of wasted energy,” says Jennifer Fortenberry, Global Product Manager, Energy & Sustainability at JLL. “Reducing light pollution means improving the energy efficiency of lighting systems, ultimately driving down carbon emissions too.”
Optimizing energy efficiency in real estate
As more companies aim to make their real estate more sustainable, lighting is one of the first areas addressed within energy efficiency plans.
In the U.S., for example, electric lighting accounts for around 40 percent of energy consumption in commercial buildings, including energy for ventilation to remove heat generated by inefficient bulbs.
Upgrading to newer bulbs is one simple measure: LEDs use up to 90 percent less energy than halogen or fluorescent lights, which release most of their energy as heat. What’s more, current LED technology is more efficient than older LEDs, says Staunton.
Smart lighting controls, which can cut energy consumption and costs by reducing wasted light, are a more advanced option. Occupancy sensors, alongside timers and internet-connected LED luminaires, control light intensity depending on how spaces are being used.
A study of luminaire-level lighting control in an open office by the Lighting Research Centre at Rensselaer Polytechnic Institute reported additional energy savings of up to 48 percent compared with manual controls. Shortening the automatic delay between space being vacated and the lights going off produced further energy reductions of up to 21 percent.
Installing power-over-Ethernet lighting networks instead of traditional electrical systems can also significantly reduce energy spend compared to LEDs on a 277V system.
“The energy and carbon reduction benefits of a well-designed system beat low-cost lamp replacement measures every time,” says Larry Lubeck, Senior Manager Portfolio Energy Manager at JLL. “Applying lighting controls across a building enables systems to be tuned according to need, which will make a huge impact on energy consumption and costs.”
Understanding lighting use
Regular assessments and audits of buildings’ night-time use can shape policies to optimize lighting use.
“Without visibility into what’s happening in a space – and when the lights need to be on - it’s difficult to know where you can reduce energy consumption,” says Fortenberry.
Audits can verify the data processed by smart systems to ensure lighting controls are appropriately deployed, avoiding issues such as sensors that detect ambient light activating around sundown despite few building occupants.
Design can also improve lighting efficiency. Outside, shielding streetlights minimizes light loss, while unidirectional fittings focus light on areas such as entrances or pathways and lessen the impact on nocturnal animals.
Inside, it’s about maximizing natural daylight, says Staunton, by choosing interior materials and colors that reflect and brighten. “This should always be a priority before turning to artificial light sources,” he adds.
Healthier environments for all
Optimizing natural light and reducing artificial sources are equally key components of healthy buildings, which are increasingly prized by both tenants and investors.
“Beyond financial return, the intangible benefits of better light quality include improved productivity, happiness and performance,” says Fortenberry. “Ultimately, this positively impacts employees, the rentability of spaces themselves, and the attractiveness of these assets to the market.”
As new sustainability regulations take effect around the world, buildings that fall short face the looming risk of a brown discount – where they’re seen as less valuable by tenants and investors than those with strong green credentials.
And while energy-efficient lighting is only a small part of making real estate more sustainable, it will nevertheless have a significant impact on the surrounding urban environment.
“It’s all about building eco-resilience and lowering climate risk,” says Staunton. “Tackling light pollution must be part of a robust ESG strategy for real estate assets.”