Architectural Lighting Design

What is architectural lighting design?

Lighting design is the art and science of lighting the human environment. It applies to both indoor and outdoor spaces.

Wikipedia defines architectural lighting design as "a field within architecture and architectural engineering that concerns itself primarily with the illumination of buildings," but lighting design is a transdisciplinary design profession that is, in fact, distinct from architectural, interior, landscape and urban design, as well as electrical and electronic engineering, yet intersects with all of them. This design discipline integrates knowledge in the natural sciences and the social sciences, as well as technology and engineering. It requires expertise in the physics of light and the physiology and the psychology of light perception by humans, also known as ergonomics or human factors. It is taught at the undergraduate and graduate academic levels, and its practicing professionals come from various backgrounds, including fine arts, design and engineering.

A view of the Manhattan skyline

A view of the Manhattan skyline

What are some of the key concerns for a lighting designer working on an urban space?

An urban space is a complex sum of parts, and the key concern in a lighting project is that the design must perform holistically. In order to create esthetic compositions that provide appropriate answers to all programmatic specificities and meet all code requirements, a lighting designer works with multiple variables. These include esthetics, program, function (the users' visual tasks, safety, orientation), context, identity, photometry, technology, sustainability and so on.

Lighting design is also a spatio-temporal design field. Both daylight and electric light are dynamic, and we design their transitions over the course of the day and night and varying programs and seasons -- I like to say that we design in at least five dimensions.

A good example of lighting in an urban space is the lighting of the High Line park in New York, which I worked on during the competition project. The design concept is esthetic and simple: The flora glows in the foreground, revealing the magical city skyline beyond. Continuous white light is mounted at a low height and provides soft yet adequate lighting for visual comfort and orientation. The context and typology make people feel safe: They are in a protected space, which is elevated and narrow, and at the same time they connect visually and cognitively with a greater environment. As a whole, the dramatic lighting scheme creates a strong identity for the park and makes a visit there a unique experience.

New York City's High Line park

The lights at New York City's High Line park as seen in The City Dark

What are the key principles or regulations guiding architectural lighting?

In lighting design, we compose space with contrast, both in brightness and hue. The key design principle is that in visual perception, nothing is absolute and all is relative, because humans have evolved a visual system that is attuned to relative relationships rather than absolute measures.

The regulatory framework for architectural lighting in the United States comprises life and safety codes, building (electrical) codes and energy codes and standards. Additional requirements can come from voluntary programs, such as green building certification programs (LEED is the best known example), and standards, guidelines and ordinances developed by professional organizations, such as the Illuminating Engineering Society (IES) and the International Association of Lighting Designers (IALD) or advocacy groups, such as the International Dark-Sky Association (IDA).

Currently, sustainability is key. New and upcoming mandatory regulations on energy efficiency address both light levels and occupancy-based controls. This is driving a widespread integration of technologies like solid state lighting (a.k.a. LEDs) and electronic controls.

Another driver is the reduction of light pollution. Some manufacturers are voluntarily offering luminaires with a label that declares them "Dark Sky Compliant." These feature "cut-off" optics to reduce glare and prevent light from spilling upward or sideways. They are commonly used in specific applications, such as roadway or site lighting, but their light distribution is not adequate for all applications and luminaire types.

It is likely that current scientific research on the impact of artificial light on circadian and ecological systems will lead to future regulations concerning the emitted spectrum of artificial light sources.

How do you think the architectural lighting industry will have changed 10 years from now?

Over just the past half-century, the global human population has almost tripled and become dominantly urban, and this trend will continue over the next 10 years. Our urban environments vary greatly in density, growth rate and size, and there now exist many megalopolises of several million inhabitants. In this global context, we must look at the right to light and the right lights: Most lighting is ad-hoc, and darkness can equate with illiteracy, respiratory illness and danger of rape or death.

There is a disconnect between pervasive lighting problems and the limited grounds of lighting design professional practice. It would be simplistic to reduce architectural lighting to energy and light pollution and to advocate "low-consumption" light sources, "dark sky compliance" optics or darkness as universal solutions. Instead, lighting must respond adequately to the complexity of all users' needs within every environment. Expanding professional lighting expertise would greatly contribute to the dissemination of architectural lighting's best practices, which are ergonomic, sustainable, ecological, esthetic and adaptive.

Lighting matters: We have a real opportunity to share the art and the science of light with the general public, and to scale up the positive contribution that lighting design professionals make in the built environment. We cannot predict how the lighting industry will have changed 10 years from now, but we can advocate for best practices to prevail.

Nathalie Rozot

Nathalie Rozot is an award-winning lighting design professional and the founder of the lighting think tank PhoScope. She is a part-time assistant professor and teaches at Parsons in the lighting design graduate program. She also regularly serves as a guest lecturer and critic and has published and lectured internationally on social and critical issues in lighting.