6 minute read
The Light Within
Exploring the Translucent Facade of The Perelman Performing Arts Center
By RANDY REID
Photo Credit: Martin Hidalgo for designing lighting(dl)
The world of architectural design is constantly evolving, with innovations emerging that redefine our understanding of space, materials, and aesthetics. Recently, a novel approach to lighting building facades has surfaced, characterized by the ingenious use of translucent marble as a primary material. This has the potential to change the way we perceive buildings, especially during the evening hours.
The Perelman Performing Arts Center (PAC NYC) in Manhattan chose this unique approach for their facade. This project not only showcases the possibilities of contemporary design but also the challenges that come with it.
Suzan Tillotson of Tillotson Design Associates discussed this architectural marvel. The conversation revealed the practical aspects of the design process, the hurdles faced, and the final impressive outcome.
At first glance, the building facade captivates observers with its luminous glow. This isn’t a result of external lighting fixtures shining on the surface. Instead, the light originates from within the facade itself, emanating a soft, consistent illumination that highlights the building’s unique structure and design. It’s a scene that can make passersby stop and admire, pondering the techniques behind such an illumination.
To achieve this luminosity, the facade employs a special construction technique.
The building is adorned with translucent, veined marble, giving it an elegant appearance in the day with its bookmatched stone. This marble, sourced from the same Vermont quarry as the U.S. Supreme Court Building and the Thomas Jefferson Memorial, is a key component of the high-performance facade.
The marble used is half an inch thick, a deliberate choice to highlight the depth of the veining. Any thicker would risk delamination due to the stone’s natural expansion and contraction.
To counter this, a layer of glass is laminated to each side of the stone, creating a seal that prevents any moisture from reaching the marble. This precaution stops the stone from hydrating and dehydrating, which could cause it to bow.
The result is a translucent sandwich of glass-stone-glass. Each sandwich unit measures 3 feet in height and 5 feet in width. The outermost piece of glass has a microtexture similar to honed stone. So convincing is this texture that many people don’t realize the outer surface is actually glass, not stone.
This three-layered composition is often referred to as an insulated glass unit (IGU). The unique composition allows interior light from chandeliers to pass through the marble, creating a mesmerizing effect that is crucial to achieving the kind of radiant glow that sets this design apart from conventional structures.
The chandeliers, which are five-foot-long bars of LEDs in a highly polished stainless steel finish, are arranged in a V-shape. There are ten chandeliers per side, per level, totaling 80 chandeliers for the entire project. Each one has a specific angle of light emission. The team had to calibrate all the optics to ensure light reached all areas of the facade evenly, including down to the floor and slab edges.
If the angle and dimming was not perfect, it would affect the illumination on the facade. A 9-degree beam of light might be perfect for a particular chandelier, but a 13-degree beam would cause too much glare or miss the wall entirely. Bars positioned at a direct angle to the glass were dimmed more than those angled downward. The downward-facing bars maintained full brightness for consistent lighting. Suzan emphasized, “There was no room for error, and every product provided had to be absolutely precise.”
The color temperature of the light was 3000K, chosen to complement the amber tint of the marble. The lighting remains constant, creating a mesmerizing effect on the facade.
The building is separated by a 4-foot floor slab/plenum; a 9’ floor slab/plenum exists at the top. Obviously, the light could not penetrate the structure separating the two floors. Supplemental lighting from i2Systems was used to create an illusion of light bleeding through the floor. From an exterior point of view, these slab edge lights prevented any unwanted shadows.
The timing of the lighting was also crucial. This building, illuminated by its own skin, stands out, especially during twilight hours. As the sun sets and natural light dims, the building begins to shine, serving as a beacon of modern architectural prowess. The team spent many hours observing the sunset to program the perfect timing for the lights to come on. As the sun sets, especially on the west facade, the light on the material is much brighter than the light that can be pushed through it due to energy code limitations. Hence, they needed to wait for the ideal moment when the sun had completely set before they could turn the lights on to their maximum brightness.
Another challenge was dealing with the refraction off the glass from wayward light trespassing from streetlights and other buildings. This is where close collaboration between the lighting design team and the owner prevented a problem. While the interior glass has a very high specular reflectivity, the exterior has more of a matte finish to help diminish the reflection of stray lumens.
Despite not being able to conduct a full-scale mockup prior to construction, the team was able to successfully execute their vision. They tested uniformity using a white fabric scrim in a theater but only had one small piece of marble for testing. They were able to overcome these limitations to achieve their desired outcome.
The project began in 2016 and was recently completed. The facade did not turn out to be a completely luminous box. This was expected by Tillotson’s team, as each 3’ x 5’ marble slab was unique. Despite this, they were extremely satisfied with the outcome.
Thoughtful design and intricate planning are ushering in a new era for architectural facades. These exteriors, previously just shields against the elements, now serve as evocative canvases that narrate tales and highlight human creativity.
The Perelman Center's facade exemplifies sustainable lighting, embedding the light source within the structure. This innovation leads to significant energy savings, less light pollution, and a seamless blend of architecture with its environment.
Translucent marble, central to this innovation, heralds exciting potential for future architectural designs, envisioning cities where buildings internally illuminate, reflecting culture, history, and achievement.
Tillotson's pioneering work on this facade is not merely an architectural achievement but signifies the progressive trajectory of design. As design horizons expand, our urban spaces become not only functional but also mirrors of our collective aspirations and creativity.
