Perspectives February 10, 2021

The importance of natural light can’t be understated—here’s why

To improve the passenger experience, Charlotte Douglas International Airport focused on light and views. Now, a recent study of user satisfaction confirms that key design decisions have yielded positive results.

Charlotte Douglas International Airport (CLT) has doubled the number of annual visitors in the past 20 years and emerged as the sixth busiest airport in the U.S. As the airport has scaled its operations, new research shows the expansion is also driving higher passenger satisfaction. In fact, users were 68% more likely to give a five-star rating on their overall experience in the new concourse compared to the existing concourse.

The study, commissioned by View Inc. and published in the Journal of Aviation Management, measured the satisfaction of more than 500 concourse visitors over the course of six days. The key finding was that there was significantly higher passenger satisfaction in Concourse A following its redesign by architecture firms Perkins&Will and C Design.

“We pride ourselves on providing an exceptional passenger experience, and this study shows that our new facilities are helping achieve that mission. As airports increasingly look to instill confidence in the travel experience, it is clear that concourse design is key to ensuring satisfaction.”

-Haley Gentry, CLT’s Acting Aviation Director

A new gateway to the airport

The Perkins&Will and C Design team shared a clear goal with their client: to redefine and enhance the user’s journey through the concourse. “This was a paradigm shift approach to the passenger experience,” says Malcolm Davis, practice leader for the North Carolina studio of Perkins&Will. This was the first project in a three-phase facility expansion, setting the standard for future design and finishes across the airport campus.”

The nine-gate concourse mimics the aerodynamic form of an airplane wing, with curved metallic ceilings and two-story views of the aircraft activity. Exposure to natural light via expansive views was a key driver of the design. The glass-walled corridor’s location—adjacent to the airport’s main entry drive— provides a sweeping visual connection to both landside and runway-side activities.


While a daylight-flooded space has obvious aesthetic appeal, it can come with less desirable side effects, namely glare and heat. Instead of resorting to window blinds or fritted glass to solve this challenge, the design team opted for a system known as Smart Windows, which automatically tint based on the position of the sun. This provides uninterrupted views while reducing glare and unwanted heat within the terminal. Manufactured by View Inc., each electrochromic glass pane is controlled by View’s Intelligence software, proactively tinting to provide control over climate and light in the space.

“We created a first-class experience by adding large circulation spaces, soaring ceilings, plentiful amenities, and a dynamic art exhibit. However, one of the most impactful design elements was the View Smart Glass glazing, which offers plentiful daylighting and unimpeded views—all while supporting our energy efficiency goals,” says Gary Beal, Aviation Market Leader at C Design.

Survey says: Light and views improve user comfort

The research into the user experience pointed to one key indicator of satisfaction: daylight. Visitors were 3.3 times more likely to be very satisfied with the concourse gate if they reported being very comfortable with the daylight conditions.

The study was led by Dr. Alan Hedge, professor emeritus in the Department of Design and Environmental Analysis at Cornell University, a year after CLT opened the Concourse A expansion. Phoenix Marketing International, which has studied passenger experience trends at CLT airport for over 10 years, surveyed 575 passengers on six clear weather days between 9 a.m. and 5 p.m. Passengers at gates on the south side of each concourse were asked about their comfort, perceptions, and satisfaction at their gate.

In addition to improving passenger comfort, the self-regulating windows reduce the building’s cooling needs, ultimately improving energy efficiency. Though the redesigned Concourse A has four times the window area of Concourse E, which has traditional windows, its seating surface temperatures were found to be 15 degrees cooler. This means travelers waiting at their gates are more thermally comfortable and the building’s owners are benefiting from reduced energy.

Survey Says: CLT passengers were 3.3 times more likely to be very satisfied with the concourse gate if they reported being very comfortable with the daylight conditions.

“Every airport is now investing in facilities that enhance the passenger experience. Most modern airport designs incorporate multi-story glass facades that bring more natural light and provide dramatic views; however, traditional glass also creates significant passenger discomfort through increased glare and heat,” said Rahul Bammi, Chief Business Officer of View, Inc. “View Smart Windows uniquely solve this problem while also reducing the airport’s carbon footprint.”

CLT is in the midst of Destination CLT, a $2.5 to $3.1 billion capital investment program that will bring additional renovations and expansions to the airport over the next five years in response to increased passenger and airline demand. In revealing concrete evidence that light and views (without heat and glare) improve user experience, this new research may very well offer a road map on how to improve the holistic airport experience.