Architectural Lighting

What is Architectural Lighting?

You may not spend a lot of time thinking about architectural lighting, but it is foundational to the feel of every space you pass through. Good architectural lighting design helps tell the story of a space, providing comfort or drama. It may suggest that you speed through a corridor or take time to linger on a work of art. 

A poorly designed lighting plan may send all the wrong messages.  A room or public space can suffer from a lack of light or from too much. The vibe of a room can be ruined with the wrong temperature of light, or productivity can fall as a result of a too-relaxed ambiance. At an even more basic level, a room with poor architectural lighting design may lead to code violations or fire hazards.

Part of what makes architectural lighting challenging is that each light source comes with a series of tradeoffs. Natural lighting is efficient and provides heat, but it’s also inconsistent and difficult to control. Some super-efficient lights are great for the environment but terrible for the feel of an architectural design. 

The first step to improving your architectural lighting design is understanding it. Below are some helpful definitions and basic concepts to help you better light whatever kind of space you are upgrading. 

A Brief Definition of Architectural Lighting

Architectural lighting encompasses all lighting systems, both natural and electric. The term references light not only as an essential utility for living and working, but also the aesthetic qualities of different light sources. Used properly, architectural lighting can draw our attention to the most interesting elements of a room or provide a feeling of safety where we would otherwise be uncomfortable. 

The three key components when evaluating architectural lighting fixtures are aesthetics, functionality, and efficiency.

Aesthetics

Not all light sources are created equal. When we consider the aesthetics of architectural lighting fixtures, we are thinking not only about the look of the light fixture, but also that of the light itself. Some sources provide a warm glow, while others provide a more sterile, blue illumination. Other aesthetic properties include whether a light source is on display or hidden, and whether or not it has a clear sense of directionality. 

Functionality

As important as the look of a light fixture is its ability to serve a particular purpose. When designing your architectural lighting, consider how you need it to help people move through a space. For example, an art gallery’s lighting should encourage passersby to spend time with a particular piece while also protecting the condition of the art. While warm lighting promotes relaxation, many offices benefit from colder light sources that encourage focus and provide strong visibility for nuanced tasks such as writing. 

Efficiency

Good lighting design should lower your energy bill and protect the environment. Efficiency extends not only to the types of lighting you use (LED, incandescent, etc.) but also to the placement of your lighting. Using reflective surfaces and well-placed fixtures can significantly improve the lighting efficiency of your space. In the long run, these savings can make a huge impact. 

Architectural Lighting Fixtures Categories

Task Lighting

Task lighting does just what you would expect. It enables a person to focus on the task at hand. As a result, selecting good task lighting is as much about brightness as it is about selecting light sources that improve contrast. 

Ambient Lighting

The partner to both task lighting and accent lighting is ambient lighting, which has the highest level of light distribution among the three categories. As you might expect, ambient lighting is the light that fills a space without a clear sense of directionality. Often one will move through a room without ever really knowing what the source of ambient lighting is. However, it is perhaps the most essential form of lighting in giving a room its character. Sources of ambient light can be natural or provided by fixtures such as recessed lights, ceiling lamps, or chandeliers.  Some types of picture lighting could be considered as ambient lighting too. Windows, skylights, and walls of glass fill the room with ambient light during the daytime, but in the evening layers of intentional ambient lighting need to be planned and installed with as much attention as to where and how large your windows should be.

Deciding on Color Temperature

Color temperature refers to the color of light. That may seem like a fuzzy concept, but there’s a lot of hard science that goes into determining the specific temperature of any light source. 

Specifically, color temperature is measured from 1000 to 10000 Kelvin, and it is the temperature at which a “black-body radiator” emits a particular color of light. A “black-body radiator” is an object that emits light that is characteristic of its temperature instead of its material composition.

The low end of the color temperature spectrum (up to about 3,000 K) includes warm colors, which are typically described as reddish and used in relaxation spaces such as living rooms and bedrooms. Above warm colors are “cool white” colors typically found between 3100 K and 4500 K. These colors are often described as being light blue or white, and they can be found in spaces such as kitchens and bathrooms. At the high end of the spectrum (4500 K and up) are daylight colors that mimic the sun’s natural lighting. Daylighting colors are typically used in spaces that require a high degree of visibility and concentration, such as a lab or a garage. 

Deciding on Brightness

Like temperature, brightness may seem like a relatively intuitive concept, but there are some concrete measurements that one should consider.  

The first of those measurements is illuminance, or the luminous flux per unit area, measured in footcandles or lux. If “luminous flux per unit area” doesn’t mean much to you, then try to think of illuminance as how bright the light would be without reflection off of any surface. 

Luminance, on the other hand, is the intensity of light reflected from a surface, and it’s measured in candelas. Luminance is a crucial consideration when considering the architectural light of a space because it forces you to consider not only your light sources but also the objects on which your light falls. Bright colors reflect more light while dark colors reflect less. And of course. Each surface can have a polished or matte finish, affecting its luminance. 

Measuring luminance and illuminance can be a challenging task requiring some relatively sophisticated calculations. There are tools that can help you calculate the illuminance of your natural light given the time of year, a crucial calculation for new buildings. Moving deeper into this topic, you can find tools that provide a dynamic view of how light will operate in your room throughout the course of a day. 

Consultants & Advisors

Now that you have some information about how architectural lighting design works, you may be wondering where you can go for some more personalized guidance. The truth is that there are a number of great sources that you may already be working with. Depending on the size of the project you are working on, you may be able to talk to your architect, interior designer, lighting designer, or energy efficiency consultant to discuss lighting solutions. Don't hesitate to use our lighting calculator.

If you are working on a much smaller project, just remember some basic rules about lighting design, which should get you pretty far on your way to a great result:

• Creating a great architectural lighting scheme is about telling a story. Things should unfold in a natural way. 
• Lighting should express the mood of a place, whether it is high- or low energy. 
• Your design should always prioritize safety and efficiency

And with that, good luck with your next architectural lighting project!

__________________________________________________________________________________________

Wyatt Dalton is a freelance writer whose work has appeared in several media outlets including Governing Magazine, Statescoop, and several blogs for Harvard University. He began his career conducting architectural research and continues to write about the built environment.