Developing successful lighting solutions

Successful lighting projects take many shapes, but there are core traits that make them shine regardless of the building type or scale.
By Sara Schonour, CannonDesign December 21, 2017

This article has been peer-reviewed.Learning objectives:

  • Understand the basic traits of a successful lighting design.
  • Review a case study of a building’s successful lighting design, taking several factors into consideration.
  • Learn about the codes and standards that offer guidance to the lighting designer.

What makes a lighting design successful? The answer may vary slightly from project to project, but the basic traits are the same—and every successful project requires a client with clear lighting goals who asks the right questions.

Figure 1: Zurich's mission is rooted in clear communication of their people-centric approach - from visual promotion of their branding message to defining what design factors they value to drive success in the creation of their new headquarters. Courtesy: With more than 140 years of experience in the insurance industry, Zurich North America believes smart investing begins with placing value on their people. The design of its new, 750,000-sq-ft headquarters located in Schaumburg, Ill., embodies this notion, providing an entire campus of amenities and people-centric working environments all geared toward optimizing their employees’ experience, satisfaction, and productivity. The project’s program offers a bit of everything—open and private office spaces, a luxurious dining café, state-of-the-art fitness facilities, a full-service auditorium, and a variety of knowledge hubs and gathering zones—each with unique character and purpose.

From the start, lighting was identified as a design element that would be integral to the realization of Zurich’s employee-focused goals as they constructed the building. To support the success of Zurich’s people and their mission, the lighting design team defined the word “success” in lighting terms and set out to deliver functional, visually comfortable, efficient, affordable, and maintainable lighting solutions that visually enhance their environments. There are many traits to successful lighting design, many of which can be achieved by asking the right questions:

Functionality and lighting design

Functionality is perhaps the obvious starting point for measuring the success of a lighting design. Lighting serves a purpose, and successful lighting needs to do its job. However, jobs can be complex and multifaceted, and there’s often a right and a wrong way to get a job done. To start off on the right path, ask the following questions:

Does the lighting serve the people who use it?

To create purpose behind the lighting being designed, a lighting designer needs to understand the needs and preferences of the people the lighting will benefit as well as the concerns of those who will install and maintain the equipment. Considering the human aspect of lighting throughout the life of a lighting design is critical to ensuring a successful overall outcome.

Are the right lighting tools being used for the job?

Figure 2: The dining and servery lighting is layered to support the various visual tasks occurring in the space while highlighting the architecture and guilding vision from station to station. Courtesy: Christopher Barrett, CannonDesignFunctional lighting is more than just lights that turn on or off. A well-designed system accounts for the myriad people using the space and the tasks they perform, and ensures the lighting conditions are best suited to those tasks. Key questions to ask include: Which surfaces are important to light, to what level, and from where? How important is color rendering? What about luminaire quality? Is ample daylight available to perform some (or all) of the lighting tasks? How much flexibility is needed for each user? What controls are needed to make the space’s lighting intuitive?

Once the functional parameters are understood, appropriate design criteria, like illuminance targets, lighting quality metrics, and control schemes, can be established to set up the design for success. Products with qualities that meet these criteria (gleaned from manufacturer data sheets, the Illuminating Engineering Society (IES) files used for calculations, etc.) can then be selected and included in the design.

Is the lighting design code-compliant?

It may sound rudimentary, but the basic lighting requirements outlined in applicable code manuals that prescribe light levels for safety (such as NFPA 70: National Electric Code, NFPA 101: Life Safety Code, International Building Code, and any local jurisdictional adoptions) and standards that dictate energy conservation and control requirements (such as ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings and the International Energy Conservation Code) represent the baseline for lighting systems in terms of occupant safety and energy performance.

These codes should always be taken into consideration as fundamental components of a functional lighting design. References, such as the U.S. Department of Energy, are useful to understand which codes are in effect for a given project. As these codes continue to be shaped by technology—and to increase energy efficiency, stronger prescriptive requirements, such as daylight harvesting, multilevel/dimmable lighting, and automatic shutoff during non-occupied hours, force lighting designers to be intimately familiar with the code requirements applicable to each project. While not required by code, if the project is targeting U.S. Green Building Council LEED certification or other sustainable certifications, there may be other prescribed energy efficiency requirements to incorporate into the design.

Has everything been properly coordinated, installed, and commissioned?

Lighting technology is complicated, and as we move into a more digital world, the opportunities—and the complexity of designs—continue to increase. As the functionality of lighting and control systems expand, there are more elements to understand and manage, which sometimes require education on behalf of users, facility maintenance teams, and sometimes even the installer.

As designers in the architectural, engineering, and construction (AEC) world, it’s likely we’ve all heard stories about complex lighting or control systems that do nothing but cause headaches because either they weren’t commissioned correctly or the responsible groups weren’t properly trained. Diligence on behalf of the designer as a project completes construction and is turned over to the client—in the form of providing sequence-of-operations intent and other commissioning information, issuing punch lists, and assisting with coordination of user training—is an essential element in ensuring the envisioned design achieves its functional goals.

For example, Zurich’s headquarters had such a wide variety of space types and people who would use them, it was important to consider each space individually in terms of function and the task that would need to be accommodated. For instance, the dining and service area have food-preparation zones with strict safety guidelines dictating illuminance levels and prohibiting equipment using lamps or lenses that can shatter and make their way into food.

As a result, the luminaires and their characteristics had much different selection criteria than the lighting intended to entice employees shopping for their lunches on the other side of the counter. For these customers, who are most concerned with how well-displayed and appetizing the food appears, the lighting needed to consider visual-quality markers like the color rendering of the food, contrast levels to make the merchandise pop, and visual cues to help organize and navigate the space.

Figure 3: The fitness areas are lit using lively, playful approaches to increase the atmosphere of activity and motion. Courtesy: Christopher Barrett, CannonDesignVisual comfort

Visual comfort is closely related to functionality and can make or break a successful lighting design. Things can look just fine on paper, but the occupants’ comfort is an important factor to consider. The link between light and health is an expanding area of study, but it’s already well-known that too much unshielded light (direct glare), lighting that doesn’t take geometries of reflective surfaces into account (indirect glare/veiling reflections), and high-contrast ratios in the field of view can cause extreme visual discomfort, which can in turn lead to all sorts of headaches—both for those living in those conditions and for those trying to fix them retroactively. A few good questions to consider:

Do the specified products address visual comfort?

Quality luminaires take visual comfort into account, and more attention has been focused on this issue with the rapid rise of LED technology. “Flicker” and stroboscopic effects perceived with poor-quality luminaires are not just visually annoying, they can trigger seizures or interfere with laser-scanning devices operating at a similar frequency. The efficiency of compact LEDs, compared with high-intensity discharge, incandescent, and fluorescent lamps, allows for smaller form factors for many luminaires while producing the high lumen outputs of their legacy sources. However, select products with caution. While a lensed 6-in. recessed slot using a T8 fluorescent source (around 400 delivered lumens per foot at the lens) would usually be considered acceptable in terms of visual comfort, standard options for LED recessed slots range up to and beyond 1,000 delivered lumens/foot in apertures as small as an inch—a combination that can feel blindingly bright. Regardless of the technology, without careful consideration of product quality, appropriate shielding, and visual geometry of people to the source, it’s easy to make a “glaring” mistake.

Does the design achieve appropriate contrast ratios?

Visual comfort is somewhat subjective as the visual experience is personal, but the IES Lighting Handbook and associated IES Recommended Practices for various applications outline maximum, average, and minimum illuminance ratios for different scenarios that are generally acceptable from a visual-comfort perspective. These guidelines take into consideration adaptation capabilities of the human eye when comparing the task areas with the surrounding field(s) of view. Verification that a lighting design adheres to these parameters is a good step toward avoiding visual-comfort problems.

Figure 4: Large expanses of treated fenestration allow natural light to pour into perimeter spaces in a controlled way, with electric lighting organized into daylighting zones outfitted with separate controls to take advantage and save energy. Courtesy: ChAre daylighting strategies a concern for visual comfort?

As energy codes and energy conservation initiatives push for the inclusion of more daylighting strategies, too much unmitigated daylight can be a visual-comfort concern. It’s not uncommon for a lighting designer to be asked to weigh in on building massing/siting, glazing/fenestration selections, and shading solutions to optimize visual comfort when a client is looking to capitalize on daylighting opportunities.

The understated, minimalist style of Zurich’s interior design aesthetic drove the lighting team toward small-scale apertures and lines of light integrated into architectural elements wherever possible. While there was a vision to enhance the design throughout the project, the occupants’ visual comfort was never sacrificed. The team paid attention to “dwell time” of employees in different spaces as we developed lighting strategies, with the understanding that the more time occupants spent in a space trying to focus, the less tolerance they would likely have for visual “distraction”—another contributor to visual comfort. In workstation areas and meeting rooms, we opted for more regular lines of continuous light in an organized pattern to promote focus and productivity. For more transient, energy-intensive areas like the fitness center, collaboration areas, and grab-and-go cafés, energetic, playful designs were used that activate the spaces and create points of visual appeal.

Efficiency

Traditional lighting systems burn around 30% to 40% of a typical commercial building’s energy, according to the U.S. Energy Information Administration, so it’s no surprise that today’s clients place a high priority on efficient lighting systems. Capitalizing on available natural light is a focus in sustainable design, and LED technology and advanced lighting controls have pushed the envelope on energy efficiency. Successful lighting designs are obviously energy code-compliant, but high-performance designs that save beyond code-prescribed allowances are often within reach by employing daylighting techniques and advanced lighting technologies. The following questions can help to optimize lighting efficiency:

Are we taking full advantage of available natural light?

Daylight is free light, and when optimized, can offset significant lighting energy costs. Several versions of ASHRAE 90.1 require a building’s lighting design to take advantage of daylight harvesting in certain perimeter zones and in spaces with skylights or clerestories. Building owners who want to get an even bigger energy benefit will take their site-specific sunpath into account when considering their building shape, programming, and design of the façade, making glazing selections that allow sunlight in while also reducing solar heat gain (to avoid taxing the mechanical systems).

Measures include shading or sunlight-redirecting devices, like louvers or light shelves, and colocating daylit areas with appropriate space types. As mentioned previously, it’s always important to consider glare and other aspects of visual comfort when integrating daylight into architectural spaces.

Is efficiency maximized in the design of the electric lighting?

With LED and other lighting technologies becoming more common, there are more luminaire choices than ever before, and source efficacy (lumens of light produced per watt of energy) has quickly increased. In many (if not most) cases, there are high-quality LED options that will save more energy than traditional luminaires.

Furthermore, luminaire designs are advancing to optimize the properties of LED optics and performance, introducing new form factors for highly efficient products that are changing age-old paradigms and guidelines for output and spacing. Often, these more efficacious sources are paired with advanced optics to allow larger distances between luminaires, resulting in not only less energy intensity, but also fewer required fixtures (an installation cost efficiency). Adding in advanced lighting controls can further reduce energy consumption and result in dramatic energy savings through automatic sensing, time scheduling, task tuning, load shedding, and daylight harvesting.

At one point in Zurich’s building design, a value-engineering option was introduced to reduce costs by using fluorescent slots instead of LED. After discussing the increased costs for fluorescent dimming ballasts in daylight zones (which were being pursued for energy benefits as well as code compliance), the value engineering was reconsidered. Around the same time, a high-efficiency slot-style product came on the market that could increase spacing and achieve the target illuminance levels and contrast ratios using fewer fixtures and less energy.

Figure 5: LED lighting approaches were specified with maintenance and longevity in mind. Courtesy: Christopher Barrett, CannonDesign 	Affordability and maintainability

Cost is always a significant design factor, and while pricing for quality lighting systems is coming down, it’s important to keep the budget in mind to avoid redesign and value-engineering work down the road. Lighting system maintenance can also be difficult if neglected in design. While LED technology offers longer life than many alternatives and several other maintenance benefits, it’s important to understand which lighting components will fail and when, and how to best respond by asking these questions:

What is the budget for the lighting system?

It’s always a good idea to have an understanding of what the client’s budget is for the lighting system design. Lighting equipment costs often vary based on quantity, location of the project, particulars of the local market, and even timing of the order. Working with lighting agents and factory representatives to help determine budget pricing at multiple stages of the design process can help keep a project on track, cost-wise, and provide options if lower-cost alternatives need to be considered.

What are the expected lifetimes of the components?

For LED products, the weakest link is usually the driver. Understanding the driver’s lifecycle and whether the driver is covered under the fixture’s warranty are key to developing a maintenance strategy. LEDs, unlike other source types, don’t usually “burn out” or catastrophically fail at end of life; instead, they slowly lose output until they are too dim to see (and if they do fail, it usually happens shortly after energization, therefore they’re easy to spot).

The industry term “L70” represents the general end of useful life of an LED module, which is at the point where the output is only 70% of the original source lumens. It’s common for an LED L70 rating to be 50,000 hours, with some cresting 100,000+ hours. If the rated life of the luminaire’s driver or the lumen maintenance information for the module aren’t readily apparent on the product’s cutsheet, these are good questions to mention to lighting agents or factory representatives.

What is the maintenance plan/future-proofing strategy to keep the system operational?

Let’s say the components are both rated for 50,000 hours—which seems like a long time. But their lifecycle depends on the operating hours and the lighting control system. With dimming, automatic sensors, daylight harvesting, and scheduled shutoff, that 50,000 hours could be stretched for quite a few years of operational life. Many facilities will accept that, in 15 to 20 years, an even more efficient system will make a good case for a retrofit upgrade. Many 24/7 applications common in hospitals, schools, industrial facilities, parking garages, etc. exceed 50,000 hours in 7 years.

How to find replacement components and whether they are easy to install are other necessary questions to ask when considering products for these types of projects, particularly for those responsible for maintaining the system. Sometimes, because the advancement of LED technology is so rapid, it’s recommended to purchase “attic stock” of certain components, especially for specialty LEDs for decorative elements, to ensure availability when it comes time for replacement.

Figure 6: Lighting approaches are integrated into the architecture for a seamless, cohesive design aesthetic while also achieving the functional lighting goals of the client. Courtesy: Christopher Barrett, CannonDesignIs the lighting equipment accessible?

Because lighting components may eventually need service, it’s important to keep access in mind. For applications that present challenges to fixture access, many products are made with remote drivers that allow the component most likely to fail to be located in a more easily maintainable area. Planning for access—remote drivers, motorized mounting points, lifts, or good old-fashioned ladders—is always a good idea.

Zurich’s all-LED lighting system is paired with a robust, web-based lighting control system that includes central and local overrides, multizone dimming, automatic sensing, and daylight harvesting throughout the complex. The high-quality products installed in the facility were vetted for appropriate lifespans, and with the benefit of the energy-saving and life-extending control system, Zurich shouldn’t have to plan for major lighting maintenance for at least 10 years.

Visual enhancement of the environment

The final component of successful lighting is a sense that the lighting “works” with the environment—the quality of light and the character of the fixtures help achieve the space’s aesthetic goals. In some cases, those goals may not be as lofty as others, but truly successful lighting is well thought out and balanced, especially when the visual experience of a space is important. The best lighting solutions are achieved as an integrated team: architect, interior designer, electrical engineer, and the other assorted team members whose work will need to be coordinated working closely with the lighting designer to create a cohesive visual concept.

Lighting approaches might enhance aspects of the architecture or materiality, reinforce hierarchy, provide visual cues and other points of focus, extend a design motif, or support particular visual sensations to create a feeling of atmosphere or mood. Once the visual idea is understood and a lighting concept to support it is created, the relevant questions that have been previously outlined can be posed to the appropriate team members to ensure the design will be a success not just in terms of aesthetics, but also as a balanced, well-designed system.

The lighting team benefitted from close collaboration with the design team throughout the process of designing Zurich’s new facility. By understanding the architectural direction, style, and material palate and collaborating with the interior designers and electrical team, we were able to create coordinated lighting details to hide fixtures in clever locations by integrating them with architectural elements, which reinforced the minimalistic yet progressive aesthetic of the client.

The result? A state-of-the-art system of high-performance luminaires and advanced controls with lighting power density of 0.43 w/sq ft that deliver to Zurich and its employees all the hallmarks of a successful design for its 750,000-sq-ft facility: functionality, visual comfort, energy efficiency, affordability, and maintainability artfully coordinated to support the project’s aesthetic and branding goals.

By working with clients to ask and answer the right questions, it sets the project up to be a success.


Sara Schonour is a vice president and head of the Lighting Studio at CannonDesign. She is a 2017 Consulting-Specifying Engineer 40 Under 40 award winner.