The world’s biggest bamboo interior space, a total of 230,000 m² (2.3 million sq.ft) of bamboo ceiling strips has been installed at Madrid Airport. Made to specification, highest fire retardant standard – M1 for public space application. Completed in 2005 with extension carry-out in 2007. The bamboo linear roof structure is connected above by a chain of roof lights, gently curved laminated bamboo laths, permitting maximum flexibility in the arrangement of accommodation on each of the floors.