Clustering around a patch of ground covered with new bricks, students from King Lam Catholic Primary School scrambled to tread on the fresh paving. Unlike traditional bricks meant simply to smooth the ground, the eco-friendly ones are the novel invention of Polytechnic University's Poon Chi-sun. Professor Poon, who is director of the university's Centre for Environmental Technology and Management, said they were made from recycled construction waste, including glass and concrete. 'The bricks help save space at congested landfill sites,' he said. They also featured on government premises and private estates. The Tseung Kwan O school is one of the five local schools featuring the eco-friendly bricks. The schools are beneficiaries of a green campaign launched by the university and HSBC Insurance to improve the school environment. A 200-square-metre plot of land at King Lam has been paved with the bricks. Principal Wong Sau-man said using them could help spread a green message among students.