Urban Greenhouse, Seoul

Seoul Botanic Park's futuristic greenhouse draws on biophilic design principles and is both an inner-city botanical conservatory and a piece of groundbreaking architecture

outh Korean architect Chanjoong Kim, director of THE_SYSTEM LAB, is a selfproclaimed maverick. Regardless of domain, he says, he seeks out projects that allow him to try something new and unorthodox. So, when the Seoul Metropolitan Government commissioned him to design the capital's first inner-city botanical conservatory as part of the new Seoul Botanic Park, the iconoclast was determined to build a greenhouse unlike any other.

The result is a circular winter garden with what Kim describes as an ‘upside-down roof ', shaped like a massive dinner plate. A series of white steel buttresses surround the roof like flower petals, while the roof 's panels — made from sustainable ETFE plastic — are irregularly shaped hexagons that mimic the way plant cells look through a microscope.

Kim, one of the nation's foremost architects, speaks more about function than aesthetics when explaining the rationale behind his design, especially the unusual concave roof. ‘For each project, I search for that one optimised solution,' he says. ‘I look for a system rather than a language.' The architect's three-pronged approach was to achieve visual harmony with the surrounding botanical garden, diversification of visitor experience and environmental friendliness.

From the outset, Kim sought to avoid erecting a large showpiece with the kind of elaborate, protruding roof often expected of a greenhouse. Instead, he advocated the dish-shaped alternative so it would appear integrated with the greater 504,000-squaremetre park, which was masterplanned by

Kyung-Jin Zoh, professor of landscape architecture at Seoul National University and chief advisor of parks and green space in the Seoul Metropolitan Government. From street level, the roof is virtually invisible save for the translucent facade and the curved buttresses that envelop the indoor garden.

The unconventional roof design also lets the park's landscape artist Ou-Gon Jon attempt unusual planting layouts. In a traditional setup, Kim says, ‘the tallest trees tend to go to the centre and people stand on the periphery, looking up to observe them.' Here, however, there is ample space at the core, while the tallest trees are spread throughout the premises. Elevated skywalks allow visitors to experience the horticulture from multiple angles.

The 7,500-square-metre conservatory is divided into the Mediterranean Zone and the Tropical Zone, two separate areas with different climate settings over which trees and plants from 12 cities on six continents have been planted.

The concave roof serves another purpose other than letting in sunlight: with the lowest point in the middle, it allows for rainwater and snow to collect in the centre, where it is then filtered and reused for gardening and lavatories.

Kim says the design initially faced scepticism from city officials who had hoped for a towering landmark for the newly developed Magok district in western Seoul. But the conservatory has been a runaway success, attracting almost seven million people since its opening — almost a quarter of Seoul Capital Area's population.