Ten more schools have joined a programme that gives secondary school students the chance to propose action plans to "green" their schools.

The Greenovate programme - a collaboration between the Building and Construction Authority (BCA), Singapore Green Building Council (SGBC), Republic Polytechnic (RP) and Johnson Controls - was launched last June with an initial group of nine secondary schools.

Following energy audits done by RP students and energy service company Johnson Controls, secondary school students in the programme draw up plans to improve the environmental sustainability of their school buildings.

Last year, students from Commonwealth Secondary School and Woodgrove Secondary School helped their schools attain BCA's Green Mark Gold and GoldPlus certifications respectively. The certification is a benchmarking scheme that aims to promote sustainability in the built environment.

Speaking at the opening ceremony of the Build-it-Green carnival yesterday, Mr Desmond Lee, Minister in the Prime Minister's Office, said that the collaboration has been extended for another year.

The three-day carnival, organised by BCA and SGBC for the third year running, is being held at Bedok Town Square. It aims to promote eco-friendly practices for families.

Mr Lee, who is also Second Minister for Home Affairs and National Development, said all Singaporeans play a significant role in ensuring the environmental sustainability of the built environment. "Changing our behaviour and mindset is the main challenge, which is why it is important to start young," he said.

The event also saw the release of an illustrated storybook, The Adventures Of Greco And Beco: The School In The Glass City, to further spread the message of conserving resources to school children.

The BCA has commissioned theVoice, a local performing arts company, to produce and stage a musical based on the new book. Performances will be held at all primary schools by the end of 2019. There was a preview yesterday for carnival visitors.

Nine-year-old Tan Kai Yee, who was at the carnival with her grandmother, Madam Goh Ai Hock, 73, a retiree, said she is looking forward to seeing the performance at her school.

The carnival is open to the public and will run till tomorrow.