How do you evaluate lighting performance in commercial design?

1 Lighting objectives

The first step in evaluating lighting performance is to define the lighting objectives for the project. What are the functional and visual requirements of the space? How do you want to create the desired mood, ambiance, and brand identity? How do you balance the natural and artificial light sources? How do you optimize the energy consumption and maintenance costs? These are some of the questions that you need to answer before you design and install the lighting system, and use them as the criteria to assess its performance.

2 Lighting metrics

In order to accurately measure and compare different lighting aspects, it is important to understand the lighting metrics that are used. Illuminance is used to measure the amount of light that falls on a surface, expressed in lux or footcandles, which indicates the brightness or visibility of a space. Luminance measures the amount of light that is emitted or reflected by a surface, expressed in candelas per square meter or nits, which indicates the contrast or glare of a space. Color temperature is used to measure the hue or tone of the light, expressed in kelvins, which indicates the warmth or coolness of a space. The Color Rendering Index (CRI) measures the ability of the light to reveal true colors of objects, expressed on a scale from 0 to 100, indicating accuracy or fidelity of a space. Lastly, Luminous efficacy measures the ratio of light output to power input, expressed in lumens per watt, indicating efficiency or sustainability of a space.

3 Lighting standards

The third step is to consult the lighting standards and guidelines that are relevant to your project. These are the minimum or recommended levels of lighting quality and performance that are established by various authorities, such as codes, regulations, certifications, or best practices. They can help you ensure that your lighting system meets the safety, health, comfort, and environmental criteria for your specific type of space, such as offices, retail, hospitality, or education.

4 Lighting tools

The fourth step is to use the lighting tools that are available to help you measure and evaluate the lighting performance. These can be either physical or digital tools, such as light meters, which measure the illuminance or luminance of a space, color meters that measure the color temperature or CRI of a space, lighting software programs that simulate and visualize the lighting effects of a space, and lighting sensors that monitor and control the lighting conditions of a space. Examples of light meters include lux meters or luminance meters; examples of color meters include spectrometers or colorimeters; examples of lighting software include Dialux, Relux, or Revit; and examples of lighting sensors include dimmers, timers, or occupancy sensors.

5 Lighting feedback

The final step in evaluating the lighting performance in commercial design is to collect and analyze the feedback from the users and occupants of the space. This qualitative aspect reflects the satisfaction, preference, and behavior of those who interact with the lighting system. To gather and interpret this feedback, you can use surveys, interviews, and observations. Surveys involve questionnaires that ask users to rate or comment on aspects like brightness, color, comfort, or mood. Interviews explore users' opinions or experiences with the lighting system. Observations record user actions or reactions to the lighting system. By following these steps, you can use the results to improve your lighting design decisions and outcomes.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?