German author Paul Scheerbart captivated architectural imagination with his visions for a future built environment made of glass in his 1914 book Glasarchitektur. In it, he not only espoused its merits as a primary façade material, but also speculated about its future manifestations for channeling light. Now, more than a century later, it turns out that he demonstrated remarkable prescience regarding our approach to building glazing: "As air is one of the worst conductors of heat, the double glass wall is an essential condition for all glass architecture,” he writes. In this same passage, Scheerbart articulates a technical capacity that would, for many decades, remain a mystery to its readers: "The light between these walls shines outward and inward, and both the outer and the inner walls may be ornamentally colored."
In 2012, the chemical company BASF and electronics corporation Philips announced this kind of capability in an organic lightemitting diode–based (OLED-based) car sunroof. A product of the companies' combined expertise, the multilayered glass module demonstrated a novel form of adaptability: In its inactivate state, the window is transparent, but when electricity is delivered, it becomes a homogeneous plane of illumination—essentially combining the functions of a window and a diffused interior light source. At the time of its publication, the technology was limited in size and clearly aimed at the automotive industry; however, Scheerbart's architectural vision would soon be fulfilled.
In 2016, two years after its founding, Vienna-based LightGlass Technology launched a line of self-illuminating glass in the U.S. market. Based on its inherently compelling nature, LightGlass “ALED” technology has positioned itself as an innovative contender within the field of smart glass technology. Unlike more common liquid crystal– or electrochromic-based approaches that provide switchable shading or opacity, LightGlass acts as its own illumination source. A closer analysis reveals its impressive potential for architecture.
ALED technology is composed of an insulating lamination of single-pane safety glass that reflects the light provided over a light-conducting surface. Thanks to its shallow installation depth, ALED can be integrated into standard building profiles, for both exterior and interior applications. According to Reinhard Tschaickner, head of marketing and PR for LightGlass, ALED offers an unprecedented capability: For the first time, it is possible for completely transparent glass to be fully and homogeneously illuminated, and in daylight quality—either to match the actual course of daylight or to be steplessly controlled within a custom color spectrum.
ALED offers a color temperature that can range between 2700K and 6500K and a luminous output starting at 2,575 lumens for “fixed white.” LightGlass’ ALED Daylight product offers 6,300 lumens; when even greater brightness is desired, its Fixed White High Brilliant provides a 10,300 lumen output. Other features include dynamic light-tuning throughout the day, automated response to contextual light conditions, and individual stepless control between full transparency and near-absolute opacity. ALED’s features may be manipulated via external switches, smart home controls, or smartphones—or at the glass itself.
Tschaickner claims that ALED “can be integrated everywhere where there is architectural glass,” including windows and doors, building façades, elevators, hospital technologies, and partition wall systems. The technology can also be incorporated into horizontal applications such as ceilings, countertops, and floors. Notably, the standard size of the product is 5 feet by 10 feet, suitable for curtainwall and other common glazing applications; larger sizes are available on request. For additional display functions, LightGlass “TechWall” enables the integration of electronic capabilities such as responsive monitors, gauges, and sensors—effectively bringing touch-responsive smartphone-screen technology to the scale of architecture.
According to Tschaickner, one of the biggest challenges of ALED has been the delivery of electricity—specifically the integration of suitable electronic components into insulating glass units. LightGlass has tested its wiring approach in several full-scale installations in Vienna: a 2.2-meter-by-1.2-meter (approximately 7-foot-by-4-foot) partition wall at the Vienna Technical Museum, an "artificial window" with marginal natural daylight for a private residence, and a "light frieze" for Austria’s Association for the Electrical and Electronics Industries. These installations tested the company’s ability to develop suitable wiring solutions and integrate them with their surrounding contexts in aesthetically acceptable ways. ALED’s electricity requirements depend on the format, glass type, and color temperature specified—ranging from 30W to 120W per square meter.
Although Tschaickner declined my request for cost information, claiming that the price depends greatly on the quantity ordered, he responded enthusiastically to my query about ALED’s potential. “LightGlass technologies provide light in daylight quality wherever we need it,” he says. “Imagine a future in which light turns into architecture—in which glass possesses new functions and intelligently participates in shaping our daily life.” One could imagine an office environment, or virtually any space, in which the primary interior light sources are its windows, thus replacing all overhead fixtures. In such an example, the nocturnal experience might become uncannily similar to that of the day, particularly with ALED’s color temperature customization capability, which could be tuned to render a perpetual sunset—or the light of high noon. Although one’s view would be obstructed at night, such technology might entice the perpetually overworked to burn even more of the midnight oil; however, it would also likely improve working conditions for the late-shift set.
Describing ALED as an “everyday life application,” Tschaickner is confident about the technology’s adoption based on building occupants’ clear understanding and habitual use of windows as their primary source of illumination. “The phrase ‘turn on the window’ will be as common as ‘turn on the light’ nowadays,” he says.
Scheerbart would doubtless be pleased.
The author does not have a stake in LightGlass Technology.