What good is a sustainable building that makes people sick?

With the need for energy-efficiency and net zero retrofits becoming ever more urgent, many building owners and operators have put sustainability at the top of their agenda—and rightly so. But of what use is a carbon-neutral building that harms the well-being of the people who work in it?

There’s a growing recognition that sustainability means sustaining the health both of the planet and health and well-being of its people. This recognition is reflected in healthy building standards such as Fitwel and the WELL Building Standard. Both acknowledge the important role that lighting has to play in making a building “healthy”. The Well Building Standard has several categories of recommendations specifically related to circadian lighting.

The WELL Building Standard is a performance-based system that awards points for measured, certified, and monitored features of the built environment. It defines standards for building features that affect human health and well-being in work environments, including lighting, air, water, nourishment, fitness, comfort, and mind.

A study conducted by researchers at MIT shows that rents for buildings with WELL certification are between 4.4% and 7.7% higher per square meter than they are for non-certified buildings. This premium for healthy spaces is independent of all other factors, such as LEED certification, building age, renovation, lease duration, and submarket. This has helped drive an explosive demand for buildings to conform to the WELL standard. More than 2,000 organizations, including 20% of Fortune 500 companies, now use WELL standards in their roadmap.

The WELL Building Standard acknowledges the fact that lighting is about much more than just whether employees can “see” well enough to do their work. Current lighting conditions in many buildings meet the visual requirements of workers but not necessarily the circadian (non-visual) requirements. To address this shortcoming, the WELL standard offers guidelines for lighting specifically designed to support improving employee well-being.

WELL specifies nine categories related to light and lighting. Three of these—L01 Light Exposure, L02 Visual Lighting Design, and L03 Circadian Lighting Design—give recommendations and requirements for the best way to deploy human-centric and melanopic lighting in a building.

• L01 seeks to support proper alignment of the human circadian rhythms with the natural day-night cycle by requiring proper indoor light exposure through daylight and electric light strategies. Daylighting strategies can be handled using windows, atriums, and skylights, and by situating workstations within a maximum distance from windows. Lighting strategies require the specific thresholds for illuminance based on an understanding of the effect of light on the human circadian system.

• L02 requires good visual lighting design, ensuring every indoor and outdoor space has the appropriate illuminance levels. The goal is to provide visual comfort and enhance visual acuity for all users through electric lighting. All indoor and outdoor spaces (including transition areas) must comply with illuminance thresholds specified in one of several industry-standard lighting reference guidelines. The illuminance must also take into consideration the tasks and the age groups of the occupants.

• L03 lays out specific requirements for supporting circadian and psychological health through indoor daylight exposure and outdoor views. These include minimum light levels for specified durations at specific times of the day.

The importance of circadian rhythm regulation and how light affects people means that a “one size fits all” approach is not sufficient for supporting workplace well-being. Many employees are not exposed to natural, bright daylight followed by darkness for a good night’s rest and melatonin production. Variable, tunable, adjustable office lighting can correct this situation by delivering the right light in the right amounts at the right times for supporting optimum circadian well-being.