Not so long ago, one of the most compelling reasons for daylighting a space was energy savings. Since the 1970s, lighting has been one of the largest users of electricity in buildings. But advances in lighting technology, namely the rapid improvement of LEDs, which are longer-lasting and more efficient than more traditional sources, are changing the discussion. Lightingâs energy consumption has been on the decline, representing 17 percent of electricity end use in commercial buildings in 2012, according to the U.S. Energy Information Association, down from 38 percent in 2003. Electric illuminationâs slice of the energy pie should fall even more as LEDs develop further and their controls become both more sophisticated and more user-friendly.
Of course, there are other arguments for designing around daylight. Architects have intuitively understood its ability to elevate the experience of their interiors. Now an increasing body of science, accumulated over decades, has quantified daylightingâs beneficial effects. One still frequently cited 1999 study examined schools in three U.S. districts and found significantly improved performance among students occupying daylit classrooms. Since then, research has demonstrated higher sales figures in skylit big-box stores, as well as better outcomes for patients in hospital rooms with daylight, including shortened stays, reduced need for pain medication, and quicker post-op recovery.
Design teams and their clients are showing renewed interest in such health and productivity benefits. One chief factor is the expansion of the green building movement to encompass occupant well-being in addition to energy efficiency, says Chad Groshart, lighting-design lead in the New Haven office of Atelier Ten, an environmental design consultant: âThe focus is no longer only on how the meter is spinning.â
One attribute of daylight that architects are keen to harness is its ability to help regulate our biological clocks, or circadian rhythms. Its spectral distribution and intensity affect a host of interrelated physiological and psychological functions including mood, alertness, and hormone levels. Designers are also eager to use electric light to improve these functions, a possibility enabled by the advent of tunable-white LEDs, which have color temperatures that can range from very warm to very cool. But experts warn that there is still debate about the optimum color, timing, and duration of exposure in such electric illumination. âCircadian lighting design is more of a lengthy experiment rather than an authoritative design standard,â says Brian Stacy, Arupâs lighting lead for the Americas. Groshart echoes this view: âSunlight is the best circadian light,â he says, advising that project teams seeking to help regulate occupantsâ internal rhythms should first focus on strategies for achieving the best quality daylight, including the orientation, form, and fenestration of the architecture.
Such factors can be readily manipulated when designing a new building, but tenant fit-out projects or the renovation of existing buildings naturally require a different approach. An example is one of Groshartâs own projects, the New York headquarters for Delos, the wellness real-estate and technology company best known for creating the WELL Building Standard (the rating system is now administered by Green Business Certification Inc.). Delos moved into its space on the fourth and fifth floors of 860 Washington Street, a new 10-story structure by James Carpenter Design Associates and Adamson Associates Architects in the cityâs Meatpacking District in late 2017. The organization picked the building in large part for its floor-to-ceiling glass curtain wall on three of its four facades, since both daylight and views are important aspects of WELL. This skin affords ample daylight and views of the adjacent High Line park and the rest of the neighborhood. (The offices have been certified WELL Platinum, have earned Living Building Challenge âpetalâ status, and are on track for a LEED Gold or Platinum rating.)
The projectâs architect, Gensler, with Atelier Ten as lighting designer, developed the 19,000-square-foot office with a variety of environments, including âfree addressâ workstations, a cafĂŠ, and meeting and focus rooms, all organized around a central stair featuring a digital artwork that is activated as occupants ascend or descend. At lea