The functionality of a building is largely dependent on the quality of its lighting. In order to safely and comfortably perform their tasks, occupants need lighting that provides adequate visibility without causing discomfort or distraction.
But a focus on quality is also the key to achieving sustainable lighting.
As Nancy Clanton, CEO of Clanton & Associates, advises, “Don’t design for energy savings; design well, and the result will be incredible energy savings.” By creating quality lighting conditions in their buildings, not only will project teams provide functional and comfortable spaces, but they’ll also achieve efficiency.
And because the lighting in a space has such a significant impact on how people use that space and how they feel while in that space, it is critical to the human-health component of sustainability. Lighting affects not only the performance and productivity of occupants but also, more critically, their well-being. High-quality lighting, beyond providing basic comfort, can protect and promote health.
The effects of lighting
Like acoustic design, lighting design can have either positive or negative effects on people, especially in the spaces where many people spend a lot of time, like schools and offices. Research has shown positive correlations between quality lighting conditions and improved productivity as well as higher student test scores. Studies also suggest that quality lighting has positive impacts in healthcare settings—for example by improving the mood and perception of both staff and patients. Conversely, poor lighting conditions can hinder the way people work, learn, and heal by causing distraction, discomfort, and fatigue.
Getting the light right is crucial. As Bob Harris, FAIA, principal at Lake|Flato Architects put it, “If you’re not doing a good job with lighting, you’re not going to be doing a good job architecturally.” He explains that lighting is often treated as a secondary concern, taking a back seat to form-making. Too often, he argues, architecture is conceived of as an object to be viewed from a detached position rather than as a habitat to be experienced and lived in.
And of course, in addition to affecting usability, comfort, and health, the way a building is lit also affects its environmental impact.
What do we mean when we say sustainable lighting?
A wide variety of sustainability issues intersect with architectural lighting. Though this report will largely focus on energy efficiency and occupant health and wellness, it is important to also consider the following related concerns when developing an integrated approach to sustainable lighting:
Light pollution—Project teams should avoid over-lighting, prevent light trespass, and consider potential impacts of lighting on the plant and animal life of the surrounding ecosystem, as well as on neighboring buildings, places, and communities.
Life-cycle impacts of lighting products—Lighting designers should work with manufacturers over time to reduce the embodied energy and carbon cost of fixtures, luminaires, and lamps. To help extend the life of the building and further reduce environmental impacts, when appropriate the lighting should be designed so that it can be easily retrofitted and adapted to align with future technology advances. (See Modular LED Lighting Enters the Mainstream and Product as a Service: Buying the Lumen, Not the Lightbulb.)
Chemicals of concern—Project teams should advocate and work with manufacturers to, over time, reduce the level of toxic materials in lighting products. For example, compact fluorescent lights, which contain highly toxic mercury, have to a large extent been replaced by LEDs, which do not contain mercury. However, sometimes LEDs are manufactured with high levels of lead and heavy metals. And some LEDs also contain copper, which can create an environmental hazard if it accumulates in waterways. (LEDs, despite their long life, will eventually need to be replaced. They can be disposed of in regular landfills, as they are not currently regulated as hazardous waste.)
High quality, low energy
The information offered in this report generally revolves around lighting design that provides building occupants with the highest-quality illumination possible—providing comfortable and safe environments in which to complete their tasks—while using as little energy as possible.
According to the Energy Information Administration, in 2010, lighting in U.S. commercial buildings required 297 billion kWh of electricity—about 22% of total commercial building electricity used in the nation. But technology has been rapidly evolving, and it’s becoming ever easier and more cost effective to drastically reduce the amount of energy consumed by lighting. In fact, LEDs have become so efficacious that additional gains in efficiency are small. The point has been reached where many in the lighting industry, who now see energy efficiency as a given, are turning most of their attention to the human-health component of sustainability and the ways that quality lighting can support it.