International Bamboo and Rattan Organisation

International Bamboo and Rattan Organisation

The Arc: Green School’s latest bamboo building

23 Aug 2021

The latest creation of the famous ‘bamboo school’ is a gym with bamboo arches that span 19 metres.

Nestled in the heart of the Balinese jungle, Green School is something of an institution. Founded in 2008 by entrepreneur John Hardy and his wife Cynthia Hardy, this international school describes itself as a ‘school of the now’: a wall-less, nature-immersed campus in the trees, which aims to inspire children’s creativity and curiosity through its surroundings. A big part of Green School’s appeal is its buildings, which are made entirely from locally sourced bamboo.

Credit: Sasha de Laage

Indeed, bamboo is more than just a building material: it is a key part of Green School’s sustainability ethos. When INBAR spoke with John Hardy in the Global Bamboo and Rattan Congress in 2015, he said: “Bamboo is the only material we can actually promise everybody. We can promise everybody an extra house with bamboo! All we have to do is plant it. It grows almost everywhere. Every shooting season I stand in the garden in Bali, and I wonder how could it be that in three years, this plant in my garden will become timber for me to build another building.”

“Bamboo is the only material we can actually promise everybody…”
                                                                  — John Hardy

Credit: Tommaso Riva

The original Green School campus was built by John Hardy’s team under the creative direction of Aldo Landwehr, and since 2010 all significant structures have been designed by IBUKU under Elora Hardy’s creative direction and built by PT Bamboo Pure. ‘The Arc’ is Green’s School latest bamboo building, built in just 8 months by IBUKU, the leading Indonesian bamboo design firm, in collaboration with bamboo construction specialist Jörg Stamm and the British structural engineering company Atelier One. Other emblematic buildings of the school include the multi-storey Heart of School and the Millennium Bridge.

Credit: Tommaso Riva

The Arc is a visually impressive creation: a 14-metre-tall, 23.5-metre-wide and 41-metre-long structure made of intersecting bamboo arches that span 19 metres. The curving roof is not just aesthetic. This ‘anticlastic structure’ derives its strength and stability from the curvature in two opposite directions, and allows the building to have a long, open space without columns.

The inspiration for this building was drawn from a human ribcage. According to Jörg Stamm, who first drew up the concept for the building: “The Arc operates like the ribs of a mammal’s chest, stabilised by tensile membranes analogous to tendons and muscles between ribs. Biologically, these highly tensile microscopic tendons transfer forces from bone to bone. In The Arc, bamboo splits transfer forces from arch to arch.”

Credit: IBUKU

This building, with a floor area of 760 square metres, will be used as a wellness space and gymnasium for the school. Dendrocalamus asper is the main local bamboo species used in its construction. It is composed of 18 arches, which are made of bundles of bamboo poles, and are ‘curved’ using the technique known in Indonesia as reb-reb, where repeated spaced incisions allow the bamboo pole to bend.

The Arc is a living example of the possibilities of round pole bamboo, and part of a promising new era for bamboo architecture: just this year, the International Organization on Standardization published a new standard on structural design with bamboo poles.

 

 

 

Indonesia is one of the founding Member States of INBAR, joining on 6 November 1997.

Other Indonesian businesses and initiatives include the Environmental Bamboo Foundation and Bamboo U.

Read INBAR’s 2018 interview with John Hardy, founder of Green School.

 INBAR coordinates international research of the structural uses of bamboo through its Construction Task Force.