Shelia Cahnman (Image credit: Organic Headshots )
In South London, King’s College Hospital’s development of a new outdoor rooftop intensive care ward stands out as one of the more interesting healthcare concepts in recent years.
The approximately 1,800-square-foot space allows critically ill patients and their staff to experience the therapeutic benefits of greenery, fresh air, and natural light in a beautiful garden atmosphere while being connected to necessary life support and monitoring systems.
Although the rooftop ward includes just six of the 60 ICU beds in the hospital’s new building, it represents a bold experiment as well as an opportunity to study the impact of structured access to the outdoors on delirium, length of stay, and long-term cognitive and psychological outcomes on patients after discharge.
While housing ICU patients outside, even for short periods of time, may be an extreme undertaking at most institutions, a recent personal experience convinced me that as healthcare designers, we haven’t advocated enough for access to natural light, views, and outdoor access in clinical spaces.
Why it’s important to advocate for natural light in healthcare spaces
This past spring, I volunteered weekly at a highly regarded major academic medical center, embedding myself within the clinical staff not as an architect but as part of their operations. My job was escorting families to see their loved ones pre- and post-surgery in holding areas and the post-anesthesia care unit (PACU). The hospital complex was a newer, beautifully designed, and well-organized facility. But working day to day in the hospital provided some additional insights.
The most striking thing I noticed was the lack of windows in the staff corridor and clinical areas due to the size of the units and necessary proximity to surgery. The short-stay unit had no windows, even with patients staying overnight. Without exterior views, there was nothing to orient users to time of day, weather, or building location. Instead, family and patient wayfinding depended completely on signage or a helpful volunteer.
While the hospital provided staff with a wonderful sunlit cafeteria, outdoor dining area, and walking path, these spaces were a great distance from most of the facilities. Furthermore, some staff members, such as the registration team, had only a 30-minute lunch break, which didn’t provide enough time to take advantage of the amenities.
WELL Building standards outline lighting criteria for healthcare environments
Within the healthcare design industry, there’s growing research on the benefits of nature in the healthcare environment, especially on inpatient units. Yet project teams continue to create larger floorplates that benefit operational efficiency while denying staff and patients natural light and views most of their day.
The International WELL Buildings Institute (IWBI) WELL Buildings V2 standard (published in 2025), a voluntary third‑party certification program, includes lighting criteria that “aims to create lighting environments that promote visual, mental, and biological health” based on extensive industry research. In addition to describing and promoting circadian lighting design as well as appropriate workplace light levels, the standard defines optimum distances to building envelope glazing (i.e., natural light and views) using two options:
- The first option requires that 30 percent of regularly occupied space be within 20 feet of exterior glazing. In common areas such as waiting rooms, 70 percent of seats must be within 16 feet of that glazing.
- The second option takes a broader architectural approach. It requires exterior glazing to make up at least 7 percent of the regularly occupied floor area, limits the floor plate to 65 feet between opposing glazed walls, and prohibits opaque obstructions taller than 4 feet within 20 feet of the glazing.
Meeting the IWBI lighting standards by building configuration alone is problematic in larger hospitals. Their diagnostic and treatment platforms of imaging, surgery, and procedural suites prioritize operational efficiency, departmental adjacency, and reduction in mechanical infrastructure over daylight and views. Patient intake and recovery areas, staff spaces, and internal corridors operate almost entirely under artificial light and are far off IWBI’s targets for circadian lighting, visual comfort, and connection to nature.
Designers simulate sky and exterior views with backlit ceilings or digital walls rather than provide true daylight access. This stands in contrast to hospital lobbies and waiting areas where generous windows with views are common. Designers must help hospitals reprioritize how diagnostic and treatment platforms are configured to create a more humane environment for patients and especially staff.
Overcoming challenges of providing natural light in hospitals
Experienced healthcare planners know the challenges of creating building perimeter for windows, especially at larger hospitals: increased enclosure cost, fewer energy savings, and less efficient floor plans with the potential for longer travel distances. But considering the importance of staff retention and emotional and psychological effects on patients and families, has the pendulum swung too far, especially on procedural and diagnostic platforms?
While the industry applauds the King’s College Hospital outdoor critical care unit, can designers use this inspiration to plan all patient-facing hospital departments with ready access to natural light and views? Ideally, this also includes access to exterior spaces if climate allows. Who will take the challenge?
Sheila Cahnman, FAIA, FACHA, LEED AP, is president, JumpGarden Consulting LLC and can be reached at [email protected].
