Skyscrapers have a contentious relationship with the sun.
Incredible amounts of time and energy are devoted to controlling how much of the sun’s radiation enters a tower. Even particular wavelengths of light are more desirable than others. It’s been a foregone conclusion that towering skyscrapers come with equally massive shadows — until now.
NBBJ’s mixed-use “shadowless” tower in London. Images courtesy NBBJ.
The global architecture and planning firm NBBJ recently unveiled a conceptual design for a pair of towers — some 50 stories tall and located in London — that would reflect sunlight onto the shadows they cast. A parametric design program within the 3D modeling software Rhinoceros used solar data, along with size requirements and other inputs, to calculate these sculptural form. The process required some tweaking but eventually it produced this iteration that reduces shadows by up to 60%. While this strategy could certainly be exported to other locations, it has some drawbacks.
The curving glass surface of the skyscraper reflects a scattered light, not a sharp beam. GIF courtesy NBBJ, via Wired.
If this GIF is any indication, the use of two complementary towers only can illuminate one of their shadows. Granted, this is just a conceptual design, but eliminating a single shadow only gets half the job done. Moreover, in sites closer to the equator the sun’s inclination is more extreme and shade might be more desirable. Lastly, it requires a measure of preexisting exposure. This is ideal for a city like London, where an ongoing surge of skyscraper construction looms over a smaller skyline, but may not find its way to New York’s financial district. Nevertheless, it appears to be one of many strategies aiming to better synergize skyscrapers and the sun.
Ateliers Jean Nouvel’s One Central Park.Photo by Murray Fredericks / via Designboom
One such project was the recently-completed One Central Park, designed by Ateliers Jean Nouvel, in Sydney. By day, an array of computer-controlled mirrors — not shown in this photograph — track the sun and beam its rays to an upper array of mirrors. They, in turn, shine the light downwards onto a rooftop garden and a shopping center beneath it. By night, LEDs take over.
Both Nouvel’s and NBBJ’s projects are developing a toolkit for architects to treat sun and shadow with greater nuance and ingenuity. Given continuing global urbanization, it seems more pertinent than even that skyscraper utilize solar radiation to benefit of their inhabitants and surroundings.