Patrick Blanc, a French botanist, believes that his patented Vertical Garden concept (http://www.verticalgardenpatrickblanc.com/) could turn Hong Kong’s concrete high-rises into green buildings.
The idea is to reduce energy consumption and insulate structures, not to mention make them pleasant to behold, a plan that I would support without reservation. Some of the city’s high-rises are well-decorated but many are not; the paint scheme is often less than attractive and after a few years attracts grime and is destroyed by air pollution.
Blanc designed the green wall in three sections: a lightweight metal frame that hangs from the wall creating an insulating air layer; a 1cm thick PVC riveted to the frame for strength and waterproofing; and a polyamide felt layer stapled to the PVC that distributes water and nutrients, eliminating the need for soil. The entire garden is about 5cm thick and weighs less than 30kg per square metre, allowing it to be installed on any size of wall, including Hong Kong’s concrete monoliths.
The main challenge is wind-resistance, given Hong Kong’s vulnerability to tropical cyclones. Blanc would solve that problem through biodiversity, as with his famous green wall at the Musee des Arts Premiers Quai Branly in Paris, which contains more than 100 plant species.
Transforming grid after grid of boring residential tower blocks into lush gardens is an immensely appealing thought that could turn Hong Kong into a modern version of the Hanging Gardens of ancient Babylon.
And the air would be a lot fresher in the bargain.