IES LP-3-10: A new lighting practice standard puts the pedestrian at the center of the lighting design
process
The Illuminating Engineering
Society (IES) unveiled a new lighting practice standard, titled Quality Lighting Design for People in
Outdoor Environments. Recently, Nancy Clanton (Clanton & Associates) and Randy Burkett (Randy Burkett
Lighting Design, Inc), members of the subcommittee that wrote the standard, presented the new lighting
guidance, which centers on design elements of outdoor space and the context and hierarchy of lighting
the nighttime environment. Rather than dealing with criteria, LP-2 presents the issues of outdoor
lighting for pedestrians with a focus on design applications. Here is a recap of Clanton and Burkett’s
introduction to LP-2-20.
The new lighting guidance centers on design elements of outdoor space
and the context and hierarchy of lighting the nighttime environment.
LP-2 flips the traditional approach of lighting outdoor spaces by putting the pedestrian, not the vehicle,
at the center of the design process. As the subcommittee began its work on LP-2, it needed to further define
a pedestrian to include not only people, but their activities: biking, riding scooters and skateboards,
rollerblading, walking, attending concerts, and so on.
Lighting design in the outdoors takes into consideration not only human activities, but also the context of
pedestrian spaces, among them the architecture, changes based on day to night, and adjacencies. Is the space
a large, open park or a series of streetscape parklets? Is it an active place? Transitions are important in
outdoor areas, and changes in lighting is an important way to signal transitions from an area, an activity,
or a task. Such context determines how a designer approaches lighting spaces for pedestrians.
Lighting design in the outdoors takes into consideration not only human
activities, but also the context of pedestrian spaces, among them the architecture, changes based on day
to night, and adjacencies.
The standard is based on a hierarchy of design elements
to consider when lighting outdoor spaces for people. Randy Burkett notes that the levels of the hierarchy
may change in importance depending on the environment that is being lit. Reassurance, for example, may
become more important in areas that are unfamiliar or associated with something negative, where safety may
be less important when lighting a gated community or familiar area.
The standard is based on a hierarchy of design elements to consider
when lighting outdoor spaces for people.
- Orientation and wayfinding help people understand a space. Orientation is an essential function of
lighting and contributes to a pedestrian feeling comfortable in a space. A person’s efforts to
navigate a space can be both conscious and subconscious. Lighting that achieves recognizable
contrasts, patterns, and predictable visual cues all aid in a person’s ability to orientate.
- Lighting that reassures is the result of objective design (meeting codes) and subjective design
(meeting the needs of a person to not feel doubtful or afraid). Lighting that allows a person to
recognize faces and expressions and is uniform are important to a person’s feeling reassured in an
outdoor space. Coherence and understanding also contribute to a sense of reassurance.
- Lighting design that reveals terrain, curbs, boundaries, and objects creates a safer, less hazardous
experience for a pedestrian. Avoiding glare, overlighting, and shadows help to create a physically
safer space.
- Lighting designers can choreograph the environment, considering CCT and spectrum, architecture,
texture and material, and function in designing lighting that creates atmosphere and enjoyment.
Lighting for atmosphere and enjoyment differs for different environments. Luminance ratios and
patterns, lighting levels and uniformity, and glare reduction are all aspects of a lighting design
that elicits emotional responses and an improved perception of the space.
Randy Burkett sums up the importance of context and considering the whole
environment and pedestrain experience with this example.
“I was working with a client on a lighting design for the city’s entire urban area.
I took places and landmarks within the city that are well-known and identified during daytime hours. I then
overlaid photos of those places and outlined the landmarks and elements within them. I was able to
demonstrate to my client that less than 15 percent of what one sees is a street or sidewalk (the horizontal
plane). Building facades, tree canopies, sculptures, play structures, furnishings, etc., make up a far
larger percentage of what we see and take in and help orient and reassure us. So why have we spent so much
time lighting streets and sidewalks and neglected the other 85 percent? Lighting designers need to be
mindful of both near field and far field conditions. It’s the total environment that defines a person’s
sense of place. The elements of the hierarchy remind us to assess the role all of these things play. It’s
how we become mindful of an environment, not just what is in front of us. It’s the context of everything
that is our field of view.”